共三个文件，和一些自定义属性，根据自己的需求使用
 
先看一下效果，边框宽度颜色都可以设置，也可以改变其中某个角的度数
 

 一：Corner注解
 
@Retention(RetentionPolicy.SOURCE)
@IntDef({
		Corner.TOP_LEFT, Corner.TOP_RIGHT,
		Corner.BOTTOM_LEFT, Corner.BOTTOM_RIGHT
})
public @interface Corner {
	int TOP_LEFT = 0;
	int TOP_RIGHT = 1;
	int BOTTOM_RIGHT = 2;
	int BOTTOM_LEFT = 3;
}
 
二：RoundedDrawable类
 
@SuppressWarnings("UnusedDeclaration")
public class RoundedDrawable extends Drawable {

	public static final String TAG = "RoundedDrawable";
	public static final int DEFAULT_BORDER_COLOR = Color.BLACK;

	private final RectF mBounds = new RectF();
	private final RectF mDrawableRect = new RectF();
	private final RectF mBitmapRect = new RectF();
	private final Bitmap mBitmap;
	private final Paint mBitmapPaint;
	private final int mBitmapWidth;
	private final int mBitmapHeight;
	private final RectF mBorderRect = new RectF();
	private final Paint mBorderPaint;
	private final Matrix mShaderMatrix = new Matrix();
	private final RectF mSquareCornersRect = new RectF();

	private Shader.TileMode mTileModeX = Shader.TileMode.CLAMP;
	private Shader.TileMode mTileModeY = Shader.TileMode.CLAMP;
	private boolean mRebuildShader = true;

	private float mCornerRadius = 0f;
	// [ topLeft, topRight, bottomLeft, bottomRight ]
	private final boolean[] mCornersRounded = new boolean[]{true, true, true, true};

	private boolean mOval = false;
	private float mBorderWidth = 0;
	private ColorStateList mBorderColor = ColorStateList.valueOf(DEFAULT_BORDER_COLOR);
	private ScaleType mScaleType = ScaleType.FIT_CENTER;

	public RoundedDrawable(Bitmap bitmap) {
		mBitmap = bitmap;

		mBitmapWidth = bitmap.getWidth();
		mBitmapHeight = bitmap.getHeight();
		mBitmapRect.set(0, 0, mBitmapWidth, mBitmapHeight);

		mBitmapPaint = new Paint();
		mBitmapPaint.setStyle(Paint.Style.FILL);
		mBitmapPaint.setAntiAlias(true);

		mBorderPaint = new Paint();
		mBorderPaint.setStyle(Paint.Style.STROKE);
		mBorderPaint.setAntiAlias(true);
		mBorderPaint.setColor(mBorderColor.getColorForState(getState(), DEFAULT_BORDER_COLOR));
		mBorderPaint.setStrokeWidth(mBorderWidth);
	}

	public static RoundedDrawable fromBitmap(Bitmap bitmap) {
		if (bitmap != null) {
			return new RoundedDrawable(bitmap);
		} else {
			return null;
		}
	}

	public static Drawable fromDrawable(Drawable drawable) {
		if (drawable != null) {
			if (drawable instanceof RoundedDrawable) {
				// just return if it's already a RoundedDrawable
				return drawable;
			} else if (drawable instanceof LayerDrawable) {
				LayerDrawable ld = (LayerDrawable) drawable;
				int num = ld.getNumberOfLayers();

				// loop through layers to and change to RoundedDrawables if possible
				for (int i = 0; i < num; i++) {
					Drawable d = ld.getDrawable(i);
					ld.setDrawableByLayerId(ld.getId(i), fromDrawable(d));
				}
				return ld;
			}

			// try to get a bitmap from the drawable and
			Bitmap bm = drawableToBitmap(drawable);
			if (bm != null) {
				return new RoundedDrawable(bm);
			}
		}
		return drawable;
	}

	public static Bitmap drawableToBitmap(Drawable drawable) {
		if (drawable instanceof BitmapDrawable) {
			return ((BitmapDrawable) drawable).getBitmap();
		}

		Bitmap bitmap;
		int width = Math.max(drawable.getIntrinsicWidth(), 2);
		int height = Math.max(drawable.getIntrinsicHeight(), 2);
		try {
			bitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
			Canvas canvas = new Canvas(bitmap);
			drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
			drawable.draw(canvas);
		} catch (Throwable e) {
			e.printStackTrace();
			Log.w(TAG, "Failed to create bitmap from drawable!");
			bitmap = null;
		}

		return bitmap;
	}

	public Bitmap getSourceBitmap() {
		return mBitmap;
	}

	@Override
	public boolean isStateful() {
		return mBorderColor.isStateful();
	}

	@Override
	protected boolean onStateChange(int[] state) {
		int newColor = mBorderColor.getColorForState(state, 0);
		if (mBorderPaint.getColor() != newColor) {
			mBorderPaint.setColor(newColor);
			return true;
		} else {
			return super.onStateChange(state);
		}
	}

	private void updateShaderMatrix() {
		float scale;
		float dx;
		float dy;

		switch (mScaleType) {
			case CENTER:
				mBorderRect.set(mBounds);
				mBorderRect.inset(mBorderWidth / 2, mBorderWidth / 2);

				mShaderMatrix.reset();
				mShaderMatrix.setTranslate((int) ((mBorderRect.width() - mBitmapWidth) * 0.5f + 0.5f),
						(int) ((mBorderRect.height() - mBitmapHeight) * 0.5f + 0.5f));
				break;

			case CENTER_CROP:
				mBorderRect.set(mBounds);
				mBorderRect.inset(mBorderWidth / 2, mBorderWidth / 2);

				mShaderMatrix.reset();

				dx = 0;
				dy = 0;

				if (mBitmapWidth * mBorderRect.height() > mBorderRect.width() * mBitmapHeight) {
					scale = mBorderRect.height() / (float) mBitmapHeight;
					dx = (mBorderRect.width() - mBitmapWidth * scale) * 0.5f;
				} else {
					scale = mBorderRect.width() / (float) mBitmapWidth;
					dy = (mBorderRect.height() - mBitmapHeight * scale) * 0.5f;
				}

				mShaderMatrix.setScale(scale, scale);
				mShaderMatrix.postTranslate((int) (dx + 0.5f) + mBorderWidth / 2,
						(int) (dy + 0.5f) + mBorderWidth / 2);
				break;

			case CENTER_INSIDE:
				mShaderMatrix.reset();

				if (mBitmapWidth <= mBounds.width() && mBitmapHeight <= mBounds.height()) {
					scale = 1.0f;
				} else {
					scale = Math.min(mBounds.width() / (float) mBitmapWidth,
							mBounds.height() / (float) mBitmapHeight);
				}

				dx = (int) ((mBounds.width() - mBitmapWidth * scale) * 0.5f + 0.5f);
				dy = (int) ((mBounds.height() - mBitmapHeight * scale) * 0.5f + 0.5f);

				mShaderMatrix.setScale(scale, scale);
				mShaderMatrix.postTranslate(dx, dy);

				mBorderRect.set(mBitmapRect);
				mShaderMatrix.mapRect(mBorderRect);
				mBorderRect.inset(mBorderWidth / 2, mBorderWidth / 2);
				mShaderMatrix.setRectToRect(mBitmapRect, mBorderRect, Matrix.ScaleToFit.FILL);
				break;

			default:
			case FIT_CENTER:
				mBorderRect.set(mBitmapRect);
				mShaderMatrix.setRectToRect(mBitmapRect, mBounds, Matrix.ScaleToFit.CENTER);
				mShaderMatrix.mapRect(mBorderRect);
				mBorderRect.inset(mBorderWidth / 2, mBorderWidth / 2);
				mShaderMatrix.setRectToRect(mBitmapRect, mBorderRect, Matrix.ScaleToFit.FILL);
				break;

			case FIT_END:
				mBorderRect.set(mBitmapRect);
				mShaderMatrix.setRectToRect(mBitmapRect, mBounds, Matrix.ScaleToFit.END);
				mShaderMatrix.mapRect(mBorderRect);
				mBorderRect.inset(mBorderWidth / 2, mBorderWidth / 2);
				mShaderMatrix.setRectToRect(mBitmapRect, mBorderRect, Matrix.ScaleToFit.FILL);
				break;

			case FIT_START:
				mBorderRect.set(mBitmapRect);
				mShaderMatrix.setRectToRect(mBitmapRect, mBounds, Matrix.ScaleToFit.START);
				mShaderMatrix.mapRect(mBorderRect);
				mBorderRect.inset(mBorderWidth / 2, mBorderWidth / 2);
				mShaderMatrix.setRectToRect(mBitmapRect, mBorderRect, Matrix.ScaleToFit.FILL);
				break;

			case FIT_XY:
				mBorderRect.set(mBounds);
				mBorderRect.inset(mBorderWidth / 2, mBorderWidth / 2);
				mShaderMatrix.reset();
				mShaderMatrix.setRectToRect(mBitmapRect, mBorderRect, Matrix.ScaleToFit.FILL);
				break;
		}

		mDrawableRect.set(mBorderRect);
		mRebuildShader = true;
	}

	@Override
	protected void onBoundsChange(@NonNull Rect bounds) {
		super.onBoundsChange(bounds);

		mBounds.set(bounds);

		updateShaderMatrix();
	}

	@Override
	public void draw(@NonNull Canvas canvas) {
		if (mRebuildShader) {
			BitmapShader bitmapShader = new BitmapShader(mBitmap, mTileModeX, mTileModeY);
			if (mTileModeX == Shader.TileMode.CLAMP && mTileModeY == Shader.TileMode.CLAMP) {
				bitmapShader.setLocalMatrix(mShaderMatrix);
			}
			mBitmapPaint.setShader(bitmapShader);
			mRebuildShader = false;
		}

		if (mOval) {
			if (mBorderWidth > 0) {
				canvas.drawOval(mDrawableRect, mBitmapPaint);
				canvas.drawOval(mBorderRect, mBorderPaint);
			} else {
				canvas.drawOval(mDrawableRect, mBitmapPaint);
			}
		} else {
			if (any(mCornersRounded)) {
				float radius = mCornerRadius;
				if (mBorderWidth > 0) {
					canvas.drawRoundRect(mDrawableRect, radius, radius, mBitmapPaint);
					canvas.drawRoundRect(mBorderRect, radius, radius, mBorderPaint);
					redrawBitmapForSquareCorners(canvas);
					redrawBorderForSquareCorners(canvas);
				} else {
					canvas.drawRoundRect(mDrawableRect, radius, radius, mBitmapPaint);
					redrawBitmapForSquareCorners(canvas);
				}
			} else {
				canvas.drawRect(mDrawableRect, mBitmapPaint);
				if (mBorderWidth > 0) {
					canvas.drawRect(mBorderRect, mBorderPaint);
				}
			}
		}
	}

	private void redrawBitmapForSquareCorners(Canvas canvas) {
		if (all(mCornersRounded)) {
			// no square corners
			return;
		}

		if (mCornerRadius == 0) {
			return; // no round corners
		}

		float left = mDrawableRect.left;
		float top = mDrawableRect.top;
		float right = left + mDrawableRect.width();
		float bottom = top + mDrawableRect.height();
		float radius = mCornerRadius;

		if (!mCornersRounded[Corner.TOP_LEFT]) {
			mSquareCornersRect.set(left, top, left + radius, top + radius);
			canvas.drawRect(mSquareCornersRect, mBitmapPaint);
		}

		if (!mCornersRounded[Corner.TOP_RIGHT]) {
			mSquareCornersRect.set(right - radius, top, right, radius);
			canvas.drawRect(mSquareCornersRect, mBitmapPaint);
		}

		if (!mCornersRounded[Corner.BOTTOM_RIGHT]) {
			mSquareCornersRect.set(right - radius, bottom - radius, right, bottom);
			canvas.drawRect(mSquareCornersRect, mBitmapPaint);
		}

		if (!mCornersRounded[Corner.BOTTOM_LEFT]) {
			mSquareCornersRect.set(left, bottom - radius, left + radius, bottom);
			canvas.drawRect(mSquareCornersRect, mBitmapPaint);
		}
	}

	private void redrawBorderForSquareCorners(Canvas canvas) {
		if (all(mCornersRounded)) {
			// no square corners
			return;
		}

		if (mCornerRadius == 0) {
			return; // no round corners
		}

		float left = mDrawableRect.left;
		float top = mDrawableRect.top;
		float right = left + mDrawableRect.width();
		float bottom = top + mDrawableRect.height();
		float radius = mCornerRadius;
		float offset = mBorderWidth / 2;

		if (!mCornersRounded[Corner.TOP_LEFT]) {
			canvas.drawLine(left - offset, top, left + radius, top, mBorderPaint);
			canvas.drawLine(left, top - offset, left, top + radius, mBorderPaint);
		}

		if (!mCornersRounded[Corner.TOP_RIGHT]) {
			canvas.drawLine(right - radius - offset, top, right, top, mBorderPaint);
			canvas.drawLine(right, top - offset, right, top + radius, mBorderPaint);
		}

		if (!mCornersRounded[Corner.BOTTOM_RIGHT]) {
			canvas.drawLine(right - radius - offset, bottom, right + offset, bottom, mBorderPaint);
			canvas.drawLine(right, bottom - radius, right, bottom, mBorderPaint);
		}

		if (!mCornersRounded[Corner.BOTTOM_LEFT]) {
			canvas.drawLine(left - offset, bottom, left + radius, bottom, mBorderPaint);
			canvas.drawLine(left, bottom - radius, left, bottom, mBorderPaint);
		}
	}

	@Override
	public int getOpacity() {
		return PixelFormat.TRANSLUCENT;
	}

	@Override
	public int getAlpha() {
		return mBitmapPaint.getAlpha();
	}

	@Override
	public void setAlpha(int alpha) {
		mBitmapPaint.setAlpha(alpha);
		invalidateSelf();
	}

	@Override
	public ColorFilter getColorFilter() {
		return mBitmapPaint.getColorFilter();
	}

	@Override
	public void setColorFilter(ColorFilter cf) {
		mBitmapPaint.setColorFilter(cf);
		invalidateSelf();
	}

	@Override
	public void setDither(boolean dither) {
		mBitmapPaint.setDither(dither);
		invalidateSelf();
	}

	@Override
	public void setFilterBitmap(boolean filter) {
		mBitmapPaint.setFilterBitmap(filter);
		invalidateSelf();
	}

	@Override
	public int getIntrinsicWidth() {
		return mBitmapWidth;
	}

	@Override
	public int getIntrinsicHeight() {
		return mBitmapHeight;
	}

	/**
	 * @return the corner radius.
	 */
	public float getCornerRadius() {
		return mCornerRadius;
	}

	/**
	 * @param corner the specific corner to get radius of.
	 * @return the corner radius of the specified corner.
	 */
	public float getCornerRadius(@Corner int corner) {
		return mCornersRounded[corner] ? mCornerRadius : 0f;
	}

	/**
	 * Sets all corners to the specified radius.
	 *
	 * @param radius the radius.
	 * @return the {@link RoundedDrawable} for chaining.
	 */
	public RoundedDrawable setCornerRadius(float radius) {
		setCornerRadius(radius, radius, radius, radius);
		return this;
	}

	/**
	 * Sets the corner radius of one specific corner.
	 *
	 * @param corner the corner.
	 * @param radius the radius.
	 * @return the {@link RoundedDrawable} for chaining.
	 */
	public RoundedDrawable setCornerRadius(@Corner int corner, float radius) {
		if (radius != 0 && mCornerRadius != 0 && mCornerRadius != radius) {
			throw new IllegalArgumentException("Multiple nonzero corner radii not yet supported.");
		}

		if (radius == 0) {
			if (only(corner, mCornersRounded)) {
				mCornerRadius = 0;
			}
			mCornersRounded[corner] = false;
		} else {
			if (mCornerRadius == 0) {
				mCornerRadius = radius;
			}
			mCornersRounded[corner] = true;
		}

		return this;
	}

	/**
	 * Sets the corner radii of all the corners.
	 *
	 * @param topLeft     top left corner radius.
	 * @param topRight    top right corner radius
	 * @param bottomRight bototm right corner radius.
	 * @param bottomLeft  bottom left corner radius.
	 * @return the {@link RoundedDrawable} for chaining.
	 */
	public RoundedDrawable setCornerRadius(float topLeft, float topRight, float bottomRight,
										   float bottomLeft) {
		Set<Float> radiusSet = new HashSet<>(4);
		radiusSet.add(topLeft);
		radiusSet.add(topRight);
		radiusSet.add(bottomRight);
		radiusSet.add(bottomLeft);

		radiusSet.remove(0f);

		if (radiusSet.size() > 1) {
			throw new IllegalArgumentException("Multiple nonzero corner radii not yet supported.");
		}

		if (!radiusSet.isEmpty()) {
			float radius = radiusSet.iterator().next();
			if (Float.isInfinite(radius) || Float.isNaN(radius) || radius < 0) {
				throw new IllegalArgumentException("Invalid radius value: " + radius);
			}
			mCornerRadius = radius;
		} else {
			mCornerRadius = 0f;
		}

		mCornersRounded[Corner.TOP_LEFT] = topLeft > 0;
		mCornersRounded[Corner.TOP_RIGHT] = topRight > 0;
		mCornersRounded[Corner.BOTTOM_RIGHT] = bottomRight > 0;
		mCornersRounded[Corner.BOTTOM_LEFT] = bottomLeft > 0;
		return this;
	}

	public float getBorderWidth() {
		return mBorderWidth;
	}

	public RoundedDrawable setBorderWidth(float width) {
		mBorderWidth = width;
		mBorderPaint.setStrokeWidth(mBorderWidth);
		return this;
	}

	public int getBorderColor() {
		return mBorderColor.getDefaultColor();
	}

	public RoundedDrawable setBorderColor(@ColorInt int color) {
		return setBorderColor(ColorStateList.valueOf(color));
	}

	public ColorStateList getBorderColors() {
		return mBorderColor;
	}

	public RoundedDrawable setBorderColor(ColorStateList colors) {
		mBorderColor = colors != null ? colors : ColorStateList.valueOf(0);
		mBorderPaint.setColor(mBorderColor.getColorForState(getState(), DEFAULT_BORDER_COLOR));
		return this;
	}

	public boolean isOval() {
		return mOval;
	}

	public RoundedDrawable setOval(boolean oval) {
		mOval = oval;
		return this;
	}

	public ScaleType getScaleType() {
		return mScaleType;
	}

	public RoundedDrawable setScaleType(ScaleType scaleType) {
		if (scaleType == null) {
			scaleType = ScaleType.FIT_CENTER;
		}
		if (mScaleType != scaleType) {
			mScaleType = scaleType;
			updateShaderMatrix();
		}
		return this;
	}

	public Shader.TileMode getTileModeX() {
		return mTileModeX;
	}

	public RoundedDrawable setTileModeX(Shader.TileMode tileModeX) {
		if (mTileModeX != tileModeX) {
			mTileModeX = tileModeX;
			mRebuildShader = true;
			invalidateSelf();
		}
		return this;
	}

	public Shader.TileMode getTileModeY() {
		return mTileModeY;
	}

	public RoundedDrawable setTileModeY(Shader.TileMode tileModeY) {
		if (mTileModeY != tileModeY) {
			mTileModeY = tileModeY;
			mRebuildShader = true;
			invalidateSelf();
		}
		return this;
	}

	private static boolean only(int index, boolean[] booleans) {
		for (int i = 0, len = booleans.length; i < len; i++) {
			if (booleans[i] != (i == index)) {
				return false;
			}
		}
		return true;
	}

	private static boolean any(boolean[] booleans) {
		for (boolean b : booleans) {
			if (b) {
				return true;
			}
		}
		return false;
	}

	private static boolean all(boolean[] booleans) {
		for (boolean b : booleans) {
			if (b) {
				return false;
			}
		}
		return true;
	}

	public Bitmap toBitmap() {
		return drawableToBitmap(this);
	}
}
 
三：RoundedImageView类
 
@SuppressWarnings("UnusedDeclaration")
public class RoundedImageView extends AppCompatImageView {

	// Constants for tile mode attributes
	private static final int TILE_MODE_UNDEFINED = -2;
	private static final int TILE_MODE_CLAMP = 0;
	private static final int TILE_MODE_REPEAT = 1;
	private static final int TILE_MODE_MIRROR = 2;

	public static final String TAG = "RoundedImageView";
	public static final float DEFAULT_RADIUS = 0f;
	public static final float DEFAULT_BORDER_WIDTH = 0f;
	public static final Shader.TileMode DEFAULT_TILE_MODE = Shader.TileMode.CLAMP;
	private static final ScaleType[] SCALE_TYPES = {
			ScaleType.MATRIX,
			ScaleType.FIT_XY,
			ScaleType.FIT_START,
			ScaleType.FIT_CENTER,
			ScaleType.FIT_END,
			ScaleType.CENTER,
			ScaleType.CENTER_CROP,
			ScaleType.CENTER_INSIDE
	};

	private final float[] mCornerRadii =
			new float[] { DEFAULT_RADIUS, DEFAULT_RADIUS, DEFAULT_RADIUS, DEFAULT_RADIUS };

	private Drawable mBackgroundDrawable;
	private ColorStateList mBorderColor =
			ColorStateList.valueOf(RoundedDrawable.DEFAULT_BORDER_COLOR);
	private float mBorderWidth = DEFAULT_BORDER_WIDTH;
	private ColorFilter mColorFilter = null;
	private boolean mColorMod = false;
	private Drawable mDrawable;
	private boolean mHasColorFilter = false;
	private boolean mIsOval = false;
	private boolean mMutateBackground = false;
	private int mResource;
	private int mBackgroundResource;
	private ScaleType mScaleType;
	private Shader.TileMode mTileModeX = DEFAULT_TILE_MODE;
	private Shader.TileMode mTileModeY = DEFAULT_TILE_MODE;

	public RoundedImageView(Context context) {
		super(context);
	}

	public RoundedImageView(Context context, AttributeSet attrs) {
		this(context, attrs, 0);
	}

	public RoundedImageView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);

		TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RoundedImageView, defStyle, 0);

		int index = a.getInt(R.styleable.RoundedImageView_android_scaleType, -1);
		if (index >= 0) {
			setScaleType(SCALE_TYPES[index]);
		} else {
			// default scaletype to FIT_CENTER
			setScaleType(ScaleType.FIT_CENTER);
		}

		float cornerRadiusOverride =
				a.getDimensionPixelSize(R.styleable.RoundedImageView_riv_corner_radius, -1);

		mCornerRadii[Corner.TOP_LEFT] =
				a.getDimensionPixelSize(R.styleable.RoundedImageView_riv_corner_radius_top_left, -1);
		mCornerRadii[Corner.TOP_RIGHT] =
				a.getDimensionPixelSize(R.styleable.RoundedImageView_riv_corner_radius_top_right, -1);
		mCornerRadii[Corner.BOTTOM_RIGHT] =
				a.getDimensionPixelSize(R.styleable.RoundedImageView_riv_corner_radius_bottom_right, -1);
		mCornerRadii[Corner.BOTTOM_LEFT] =
				a.getDimensionPixelSize(R.styleable.RoundedImageView_riv_corner_radius_bottom_left, -1);

		boolean any = false;
		for (int i = 0, len = mCornerRadii.length; i < len; i++) {
			if (mCornerRadii[i] < 0) {
				mCornerRadii[i] = 0f;
			} else {
				any = true;
			}
		}

		if (!any) {
			if (cornerRadiusOverride < 0) {
				cornerRadiusOverride = DEFAULT_RADIUS;
			}
			for (int i = 0, len = mCornerRadii.length; i < len; i++) {
				mCornerRadii[i] = cornerRadiusOverride;
			}
		}

		mBorderWidth = a.getDimensionPixelSize(R.styleable.RoundedImageView_riv_border_width, -1);
		if (mBorderWidth < 0) {
			mBorderWidth = DEFAULT_BORDER_WIDTH;
		}

		mBorderColor = a.getColorStateList(R.styleable.RoundedImageView_riv_border_color);
		if (mBorderColor == null) {
			mBorderColor = ColorStateList.valueOf(RoundedDrawable.DEFAULT_BORDER_COLOR);
		}

		mMutateBackground = a.getBoolean(R.styleable.RoundedImageView_riv_mutate_background, false);
		mIsOval = a.getBoolean(R.styleable.RoundedImageView_riv_oval, false);

		final int tileMode = a.getInt(R.styleable.RoundedImageView_riv_tile_mode, TILE_MODE_UNDEFINED);
		if (tileMode != TILE_MODE_UNDEFINED) {
			setTileModeX(parseTileMode(tileMode));
			setTileModeY(parseTileMode(tileMode));
		}

		final int tileModeX =
				a.getInt(R.styleable.RoundedImageView_riv_tile_mode_x, TILE_MODE_UNDEFINED);
		if (tileModeX != TILE_MODE_UNDEFINED) {
			setTileModeX(parseTileMode(tileModeX));
		}

		final int tileModeY =
				a.getInt(R.styleable.RoundedImageView_riv_tile_mode_y, TILE_MODE_UNDEFINED);
		if (tileModeY != TILE_MODE_UNDEFINED) {
			setTileModeY(parseTileMode(tileModeY));
		}

		updateDrawableAttrs();
		updateBackgroundDrawableAttrs(true);

		if (mMutateBackground) {
			//noinspection deprecation
			super.setBackgroundDrawable(mBackgroundDrawable);
		}

		a.recycle();
	}

	private static Shader.TileMode parseTileMode(int tileMode) {
		switch (tileMode) {
			case TILE_MODE_CLAMP:
				return Shader.TileMode.CLAMP;
			case TILE_MODE_REPEAT:
				return Shader.TileMode.REPEAT;
			case TILE_MODE_MIRROR:
				return Shader.TileMode.MIRROR;
			default:
				return null;
		}
	}

	@Override
	protected void drawableStateChanged() {
		super.drawableStateChanged();
		invalidate();
	}

	@Override
	public ScaleType getScaleType() {
		return mScaleType;
	}

	@Override
	public void setScaleType(ScaleType scaleType) {
		assert scaleType != null;

		if (mScaleType != scaleType) {
			mScaleType = scaleType;

			switch (scaleType) {
				case CENTER:
				case CENTER_CROP:
				case CENTER_INSIDE:
				case FIT_CENTER:
				case FIT_START:
				case FIT_END:
				case FIT_XY:
					super.setScaleType(ScaleType.FIT_XY);
					break;
				default:
					super.setScaleType(scaleType);
					break;
			}

			updateDrawableAttrs();
			updateBackgroundDrawableAttrs(false);
			invalidate();
		}
	}

	@Override
	public void setImageDrawable(Drawable drawable) {
		mResource = 0;
		mDrawable = RoundedDrawable.fromDrawable(drawable);
		updateDrawableAttrs();
		super.setImageDrawable(mDrawable);
	}

	@Override
	public void setImageBitmap(Bitmap bm) {
		mResource = 0;
		mDrawable = RoundedDrawable.fromBitmap(bm);
		updateDrawableAttrs();
		super.setImageDrawable(mDrawable);
	}

	@Override
	public void setImageResource(@DrawableRes int resId) {
		if (mResource != resId) {
			mResource = resId;
			mDrawable = resolveResource();
			updateDrawableAttrs();
			super.setImageDrawable(mDrawable);
		}
	}

	@Override public void setImageURI(Uri uri) {
		super.setImageURI(uri);
		setImageDrawable(getDrawable());
	}

	private Drawable resolveResource() {
		Resources rsrc = getResources();
		if (rsrc == null) { return null; }

		Drawable d = null;

		if (mResource != 0) {
			try {
				d = rsrc.getDrawable(mResource);
			} catch (Exception e) {
				Log.w(TAG, "Unable to find resource: " + mResource, e);
				// Don't try again.
				mResource = 0;
			}
		}
		return RoundedDrawable.fromDrawable(d);
	}

	@Override
	public void setBackground(Drawable background) {
		setBackgroundDrawable(background);
	}

	@Override
	public void setBackgroundResource(@DrawableRes int resId) {
		if (mBackgroundResource != resId) {
			mBackgroundResource = resId;
			mBackgroundDrawable = resolveBackgroundResource();
			setBackgroundDrawable(mBackgroundDrawable);
		}
	}

	@Override
	public void setBackgroundColor(int color) {
		mBackgroundDrawable = new ColorDrawable(color);
		setBackgroundDrawable(mBackgroundDrawable);
	}

	private Drawable resolveBackgroundResource() {
		Resources rsrc = getResources();
		if (rsrc == null) { return null; }

		Drawable d = null;

		if (mBackgroundResource != 0) {
			try {
				d = rsrc.getDrawable(mBackgroundResource);
			} catch (Exception e) {
				Log.w(TAG, "Unable to find resource: " + mBackgroundResource, e);
				// Don't try again.
				mBackgroundResource = 0;
			}
		}
		return RoundedDrawable.fromDrawable(d);
	}

	private void updateDrawableAttrs() {
		updateAttrs(mDrawable, mScaleType);
	}

	private void updateBackgroundDrawableAttrs(boolean convert) {
		if (mMutateBackground) {
			if (convert) {
				mBackgroundDrawable = RoundedDrawable.fromDrawable(mBackgroundDrawable);
			}
			updateAttrs(mBackgroundDrawable, ScaleType.FIT_XY);
		}
	}

	@Override public void setColorFilter(ColorFilter cf) {
		if (mColorFilter != cf) {
			mColorFilter = cf;
			mHasColorFilter = true;
			mColorMod = true;
			applyColorMod();
			invalidate();
		}
	}

	private void applyColorMod() {
		// Only mutate and apply when modifications have occurred. This should
		// not reset the mColorMod flag, since these filters need to be
		// re-applied if the Drawable is changed.
		if (mDrawable != null && mColorMod) {
			mDrawable = mDrawable.mutate();
			if (mHasColorFilter) {
				mDrawable.setColorFilter(mColorFilter);
			}
			// TODO: support, eventually...
			//mDrawable.setXfermode(mXfermode);
			//mDrawable.setAlpha(mAlpha * mViewAlphaScale >> 8);
		}
	}

	private void updateAttrs(Drawable drawable, ScaleType scaleType) {
		if (drawable == null) { return; }

		if (drawable instanceof RoundedDrawable) {
			((RoundedDrawable) drawable)
					.setScaleType(scaleType)
					.setBorderWidth(mBorderWidth)
					.setBorderColor(mBorderColor)
					.setOval(mIsOval)
					.setTileModeX(mTileModeX)
					.setTileModeY(mTileModeY);

			if (mCornerRadii != null) {
				((RoundedDrawable) drawable).setCornerRadius(
						mCornerRadii[Corner.TOP_LEFT],
						mCornerRadii[Corner.TOP_RIGHT],
						mCornerRadii[Corner.BOTTOM_RIGHT],
						mCornerRadii[Corner.BOTTOM_LEFT]);
			}

			applyColorMod();
		} else if (drawable instanceof LayerDrawable) {
			// loop through layers to and set drawable attrs
			LayerDrawable ld = ((LayerDrawable) drawable);
			for (int i = 0, layers = ld.getNumberOfLayers(); i < layers; i++) {
				updateAttrs(ld.getDrawable(i), scaleType);
			}
		}
	}

	@Override
	@Deprecated
	public void setBackgroundDrawable(Drawable background) {
		mBackgroundDrawable = background;
		updateBackgroundDrawableAttrs(true);
		//noinspection deprecation
		super.setBackgroundDrawable(mBackgroundDrawable);
	}

	/**
	 * @return the largest corner radius.
	 */
	public float getCornerRadius() {
		return getMaxCornerRadius();
	}

	/**
	 * @return the largest corner radius.
	 */
	public float getMaxCornerRadius() {
		float maxRadius = 0;
		for (float r : mCornerRadii) {
			maxRadius = Math.max(r, maxRadius);
		}
		return maxRadius;
	}

	/**
	 * Get the corner radius of a specified corner.
	 *
	 * @param corner the corner.
	 * @return the radius.
	 */
	public float getCornerRadius(@Corner int corner) {
		return mCornerRadii[corner];
	}

	/**
	 * Set all the corner radii from a dimension resource id.
	 *
	 * @param resId dimension resource id of radii.
	 */
	public void setCornerRadiusDimen(@DimenRes int resId) {
		float radius = getResources().getDimension(resId);
		setCornerRadius(radius, radius, radius, radius);
	}

	/**
	 * Set the corner radius of a specific corner from a dimension resource id.
	 *
	 * @param corner the corner to set.
	 * @param resId the dimension resource id of the corner radius.
	 */
	public void setCornerRadiusDimen(@Corner int corner, @DimenRes int resId) {
		setCornerRadius(corner, getResources().getDimensionPixelSize(resId));
	}

	/**
	 * Set the corner radii of all corners in px.
	 *
	 * @param radius the radius to set.
	 */
	public void setCornerRadius(float radius) {
		setCornerRadius(radius, radius, radius, radius);
	}

	/**
	 * Set the corner radius of a specific corner in px.
	 *
	 * @param corner the corner to set.
	 * @param radius the corner radius to set in px.
	 */
	public void setCornerRadius(@Corner int corner, float radius) {
		if (mCornerRadii[corner] == radius) {
			return;
		}
		mCornerRadii[corner] = radius;

		updateDrawableAttrs();
		updateBackgroundDrawableAttrs(false);
		invalidate();
	}

	/**
	 * Set the corner radii of each corner individually. Currently only one unique nonzero value is
	 * supported.
	 *
	 * @param topLeft radius of the top left corner in px.
	 * @param topRight radius of the top right corner in px.
	 * @param bottomRight radius of the bottom right corner in px.
	 * @param bottomLeft radius of the bottom left corner in px.
	 */
	public void setCornerRadius(float topLeft, float topRight, float bottomLeft, float bottomRight) {
		if (mCornerRadii[Corner.TOP_LEFT] == topLeft
				&& mCornerRadii[Corner.TOP_RIGHT] == topRight
				&& mCornerRadii[Corner.BOTTOM_RIGHT] == bottomRight
				&& mCornerRadii[Corner.BOTTOM_LEFT] == bottomLeft) {
			return;
		}

		mCornerRadii[Corner.TOP_LEFT] = topLeft;
		mCornerRadii[Corner.TOP_RIGHT] = topRight;
		mCornerRadii[Corner.BOTTOM_LEFT] = bottomLeft;
		mCornerRadii[Corner.BOTTOM_RIGHT] = bottomRight;

		updateDrawableAttrs();
		updateBackgroundDrawableAttrs(false);
		invalidate();
	}

	public float getBorderWidth() {
		return mBorderWidth;
	}

	public void setBorderWidth(@DimenRes int resId) {
		setBorderWidth(getResources().getDimension(resId));
	}

	public void setBorderWidth(float width) {
		if (mBorderWidth == width) { return; }

		mBorderWidth = width;
		updateDrawableAttrs();
		updateBackgroundDrawableAttrs(false);
		invalidate();
	}

	@ColorInt
	public int getBorderColor() {
		return mBorderColor.getDefaultColor();
	}

	public void setBorderColor(@ColorInt int color) {
		setBorderColor(ColorStateList.valueOf(color));
	}

	public ColorStateList getBorderColors() {
		return mBorderColor;
	}

	public void setBorderColor(ColorStateList colors) {
		if (mBorderColor.equals(colors)) { return; }

		mBorderColor =
				(colors != null) ? colors : ColorStateList.valueOf(RoundedDrawable.DEFAULT_BORDER_COLOR);
		updateDrawableAttrs();
		updateBackgroundDrawableAttrs(false);
		if (mBorderWidth > 0) {
			invalidate();
		}
	}

	/**
	 * Return true if this view should be oval and always set corner radii to half the height or
	 * width.
	 *
	 * @return if this {@link RoundedImageView} is set to oval.
	 */
	public boolean isOval() {
		return mIsOval;
	}

	/**
	 * Set if the drawable should ignore the corner radii set and always round the source to
	 * exactly half the height or width.
	 *
	 * @param oval if this {@link RoundedImageView} should be oval.
	 */
	public void setOval(boolean oval) {
		mIsOval = oval;
		updateDrawableAttrs();
		updateBackgroundDrawableAttrs(false);
		invalidate();
	}

	public Shader.TileMode getTileModeX() {
		return mTileModeX;
	}

	public void setTileModeX(Shader.TileMode tileModeX) {
		if (this.mTileModeX == tileModeX) { return; }

		this.mTileModeX = tileModeX;
		updateDrawableAttrs();
		updateBackgroundDrawableAttrs(false);
		invalidate();
	}

	public Shader.TileMode getTileModeY() {
		return mTileModeY;
	}

	public void setTileModeY(Shader.TileMode tileModeY) {
		if (this.mTileModeY == tileModeY) { return; }

		this.mTileModeY = tileModeY;
		updateDrawableAttrs();
		updateBackgroundDrawableAttrs(false);
		invalidate();
	}

	/**
	 * If {@code true}, we will also round the background drawable according to the settings on this
	 * ImageView.
	 *
	 * @return whether the background is mutated.
	 */
	public boolean mutatesBackground() {
		return mMutateBackground;
	}

	/**
	 * Set whether the {@link RoundedImageView} should round the background drawable according to
	 * the settings in addition to the source drawable.
	 *
	 * @param mutate true if this view should mutate the background drawable.
	 */
	public void mutateBackground(boolean mutate) {
		if (mMutateBackground == mutate) { return; }

		mMutateBackground = mutate;
		updateBackgroundDrawableAttrs(true);
		invalidate();
	}
}
 
四：自定义的属性
 
<declare-styleable name="RoundedImageView">
        <attr name="riv_corner_radius" format="dimension" />
        <attr name="riv_corner_radius_top_left" format="dimension" />
        <attr name="riv_corner_radius_top_right" format="dimension" />
        <attr name="riv_corner_radius_bottom_left" format="dimension" />
        <attr name="riv_corner_radius_bottom_right" format="dimension" />
        <attr name="riv_border_width" format="dimension" />
        <attr name="riv_border_color" format="color" />
        <attr name="riv_mutate_background" format="boolean" />
        <attr name="riv_oval" format="boolean" />
        <attr name="android:scaleType" format="integer" />
        <attr name="riv_tile_mode" format="integer">
            <enum name="clamp" value="0" />
            <enum name="repeat" value="1" />
            <enum name="mirror" value="2" />
        </attr>
        <attr name="riv_tile_mode_x" format="integer">
            <enum name="clamp" value="0" />
            <enum name="repeat" value="1" />
            <enum name="mirror" value="2" />
        </attr>
        <attr name="riv_tile_mode_y" format="integer">
            <enum name="clamp" value="0" />
            <enum name="repeat" value="1" />
            <enum name="mirror" value="2" />
        </attr>
    </declare-styleable>

在css3中实现半圆、圆、不同度数的圆角都是通过border-radius来实现的，
 
接下来将展示通过行内样式来实现以下效果！
 
颜色随机选的~~
 
 
 代码如下，需要自取
 
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div style="width: 200px; height: 100px; background-color: rgb(0,123,8); border-radius: 50%;"></div>

  <div style="width: 200px; height: 200px; background-color: rgb(255,195,206); border-radius: 10px 20px 30px 40px;"></div>

  <div style="width: 200px; height: 200px; background-color: rgb(137,208,236); border-radius: 50% 0 50% 0;"></div>

  <div style="width: 200px; height: 200px; background-color: rgb(154,205,57); border-radius: 50% 50% 50% 0;"></div>

  <div style="width: 200px; height: 100px; background-color: rgb(255,216,27); border-radius: 100px 100px 0 0;"></div>
  
  <div style="width: 100px; height: 200px; background-color: rgb(121,0,120); border-radius: 100px 0 0 100px;"></div>
</body>
</html>
 

  //Glide设置图片圆角角度
    RoundedCorners roundedCorners = new RoundedCorners(50);
  //通过RequestOptions扩展功能,override:采样率,因为ImageView就这么大,可以压缩图片,降低内存消耗
   // RequestOptions options = RequestOptions.bitmapTransform(roundedCorners).override(20, 20);
       RequestOptions options = RequestOptions.bitmapTransform(roundedCorners);
   Glide.with(mContext).load(mUrlList.get(position % mUrlList.size())).apply(options).into(iv);

使用贝塞尔曲线
 
 
 
typedef NS_OPTIONS(NSUInteger, UIRectCorner) {
 
 
    UIRectCornerTopLeft     = 1 << 0,
 
 
    UIRectCornerTopRight    = 1 << 1,
 
 
    UIRectCornerBottomLeft  = 1 << 2,
 
 
    UIRectCornerBottomRight = 1 << 3,
 
 
    UIRectCornerAllCorners  = ~0UL
 
 
};
 
 
 
 
//16进制颜色
 
 
#define RGB16Color(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 green:((float)((rgbValue & 0xFF00) >> 8))/255.0 blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]
 
 
 
 
 
UIButton * chooseButton = [UIButton buttonWithType:UIButtonTypeCustom];
 
 
chooseButton.frame = CGRectMake(10, 15, 86, 24);
 
 
[self.view addSubview:chooseButton];
 
 
UIBezierPath *maskPath_two = [UIBezierPath bezierPathWithRoundedRect: chooseButton.bounds byRoundingCorners:UIRectCornerTopRight | UIRectCornerBottomRight cornerRadii:CGSizeMake(5,5)];
 
 
    //创建 layer
 
 
    CAShapeLayer *maskLayer_two = [[CAShapeLayer alloc] init];
 
 
    maskLayer_two.frame = chooseButton.bounds;
 
 
    //赋值
 
 
    maskLayer_two.path = maskPath_two.CGPath;
 
 
    chooseButton.layer.mask = maskLayer_two;
 
 
在以上的基础上 设置边框
 
 
 
//设置边框
 
 
    CAShapeLayer *borderLayer = [CAShapeLayer layer];
 
 
    borderLayer.frame = chooseButton.bounds;
 
 
    borderLayer.path = maskPath_two.CGPath;
 
 
    borderLayer.lineWidth = 1;
 
 
    borderLayer.fillColor = [UIColor clearColor].CGColor;
 
 
    borderLayer.strokeColor = RGB16Color(0x30C26D).CGColor;
 
 
    [chooseButton.layer addSublayer:borderLayer];