2015-05-23 11:30:54 sammyieveo 阅读数 840


在需要模糊的UIView上,添加一个UIVisualEffectView对象即可,若直接在storyboad里面直接加UIVisualEffectView,你的项目必须是iOS8以上才能用


- (void)viewDidLoad {

    [super viewDidLoad];

//    UIImageView *imageview = [[UIImageView alloc] init];

//    

//    imageview.frame = CGRectMake(10, 200, 300, 300);

//    

//    imageview.image = [UIImage imageNamed:@"2"];

//    

//    imageview.contentMode = UIViewContentModeScaleAspectFit;

//    

//    imageview.userInteractionEnabled = YES;

//    

//    [self.view addSubview:imageview];

    

    

    

    UIBlurEffect *blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];

    

    UIVisualEffectView *effectview = [[UIVisualEffectView alloc] initWithEffect:blur];

    

   // effectview.frame = CGRectMake(0, 0, imageview.frame.size.width/2, 300);

    effectview.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);

    

    

    //[imageview addSubview:effectview];

    [self.view addSubview:effectview];

    

    UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];

    

    btn.frame = CGRectMake(10, 50, 100, 40);

    

    [btn setTitle:@"btn" forState:UIControlStateNormal];

    

    [effectview.contentView addSubview:btn];

    

  

}



2017-11-17 17:11:33 YCM1101743158 阅读数 260

iOS常见的截图模糊问题解决办法

主要原因:是在iOS7 的分辨率 会改为另外一种代替的方法

iOS7之前是UIGraphicsBeginImageContext

iOS7之后是UIGraphicsBeginImageContextWithOptions

+(UIImage*)captureScreen:(UIView*)viewToCapture

{
    UIGraphicsBeginImageContextWithOptions(viewToCapture.bounds.size, NO, 0.0);
    [viewToCapture.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return viewImage;

}



 UIGraphicsBeginImageContext(viewToCapture.bounds.size);//模糊
    UIGraphicsBeginImageContextWithOptions(viewToCapture.bounds.size, NO, 0.0);//原图

2015-12-01 13:43:45 u012897297 阅读数 236
注:该内容从极客网学习而来。
先看个效果图:

实现方法一:利用ios8中得系统原生类 UIVisualEffectView 、UIVibrancyEffect

ios8才出得类昂,切记。

 // 创建一个模糊view,添加到UIImageView上
    UIVisualEffectView *viewEbg = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleLight]];
    viewEbg.frame = CGRectMake(0, 100, 375, 500);
    [self.imgView addSubview:viewEbg];
    
    
    
    // 创建一个子模糊view,添加在父模糊view上
    UIVisualEffectView *subV = [[UIVisualEffectView alloc] initWithEffect:[UIVibrancyEffect effectForBlurEffect:(UIBlurEffect *)viewEbg.effect]];
    // 该类的view 是用 contentView 来添加子控件的
    [viewEbg.contentView addSubview:subV];
    subV.frame = viewEbg.bounds;
    
    UILabel *la = [[UILabel alloc ] initWithFrame:subV.bounds];
    la.text = @"你好";
    la.textColor = [UIColor redColor];
    la.font = [UIFont systemFontOfSize:60.0];
    la.textAlignment = NSTextAlignmentCenter;
    [subV.contentView addSubview:la];

体会:效果跟图片有很大的关系,假如代码不变,只换一张图片,那么效果就是下面这样:



官方文档介绍:



方法二:可以借助别人的分类 UIImage+ImageEffects.h //也支持ios7昂

用起来特别方便

UIImage+ImageEffects.h

@import UIKit;

@interface UIImage (ImageEffects)

#pragma mark - Blur Image

/**
 *  Get blured image.
 *
 *  @return Blured image.
 */
- (UIImage *)blurImage;

/**
 *  Get the blured image masked by another image.
 *
 *  @param maskImage Image used for mask.
 *
 *  @return the Blured image.
 */
- (UIImage *)blurImageWithMask:(UIImage *)maskImage;

/**
 *  Get blured image and you can set the blur radius.
 *
 *  @param radius Blur radius.
 *
 *  @return Blured image.
 */
- (UIImage *)blurImageWithRadius:(CGFloat)radius;

/**
 *  Get blured image at specified frame.
 *
 *  @param frame The specified frame that you use to blur.
 *
 *  @return Blured image.
 */
- (UIImage *)blurImageAtFrame:(CGRect)frame;

#pragma mark - Grayscale Image

/**
 *  Get grayScale image.
 *
 *  @return GrayScaled image.
 */
- (UIImage *)grayScale;

#pragma mark - Some Useful Method

/**
 *  Scale image with fixed width.
 *
 *  @param width The fixed width you give.
 *
 *  @return Scaled image.
 */
- (UIImage *)scaleWithFixedWidth:(CGFloat)width;

/**
 *  Scale image with fixed height.
 *
 *  @param height The fixed height you give.
 *
 *  @return Scaled image.
 */
- (UIImage *)scaleWithFixedHeight:(CGFloat)height;

/**
 *  Get the image average color.
 *
 *  @return Average color from the image.
 */
- (UIColor *)averageColor;

/**
 *  Get cropped image at specified frame.
 *
 *  @param frame The specified frame that you use to crop.
 *
 *  @return Cropped image
 */
- (UIImage *)croppedImageAtFrame:(CGRect)frame;

@end


UIImage+ImageEffects.m

/*
     File: UIImage+ImageEffects.m
 Abstract: This is a category of UIImage that adds methods to apply blur and tint effects to an image. This is the code you’ll want to look out to find out how to use vImage to efficiently calculate a blur.
  Version: 1.0
 
 Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple
 Inc. ("Apple") in consideration of your agreement to the following
 terms, and your use, installation, modification or redistribution of
 this Apple software constitutes acceptance of these terms.  If you do
 not agree with these terms, please do not use, install, modify or
 redistribute this Apple software.
 
 In consideration of your agreement to abide by the following terms, and
 subject to these terms, Apple grants you a personal, non-exclusive
 license, under Apple's copyrights in this original Apple software (the
 "Apple Software"), to use, reproduce, modify and redistribute the Apple
 Software, with or without modifications, in source and/or binary forms;
 provided that if you redistribute the Apple Software in its entirety and
 without modifications, you must retain this notice and the following
 text and disclaimers in all such redistributions of the Apple Software.
 Neither the name, trademarks, service marks or logos of Apple Inc. may
 be used to endorse or promote products derived from the Apple Software
 without specific prior written permission from Apple.  Except as
 expressly stated in this notice, no other rights or licenses, express or
 implied, are granted by Apple herein, including but not limited to any
 patent rights that may be infringed by your derivative works or by other
 works in which the Apple Software may be incorporated.
 
 The Apple Software is provided by Apple on an "AS IS" basis.  APPLE
 MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
 THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
 FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
 OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
 
 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
 OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,
 MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED
 AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),
 STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 
 Copyright (C) 2013 Apple Inc. All Rights Reserved.
 
 
 Copyright © 2013 Apple Inc. All rights reserved.
 WWDC 2013 License
 
 NOTE: This Apple Software was supplied by Apple as part of a WWDC 2013
 Session. Please refer to the applicable WWDC 2013 Session for further
 information.
 
 IMPORTANT: This Apple software is supplied to you by Apple Inc.
 ("Apple") in consideration of your agreement to the following terms, and
 your use, installation, modification or redistribution of this Apple
 software constitutes acceptance of these terms. If you do not agree with
 these terms, please do not use, install, modify or redistribute this
 Apple software.
 
 In consideration of your agreement to abide by the following terms, and
 subject to these terms, Apple grants you a non-exclusive license, under
 Apple's copyrights in this original Apple software (the "Apple
 Software"), to use, reproduce, modify and redistribute the Apple
 Software, with or without modifications, in source and/or binary forms;
 provided that if you redistribute the Apple Software in its entirety and
 without modifications, you must retain this notice and the following
 text and disclaimers in all such redistributions of the Apple Software.
 Neither the name, trademarks, service marks or logos of Apple Inc. may
 be used to endorse or promote products derived from the Apple Software
 without specific prior written permission from Apple. Except as
 expressly stated in this notice, no other rights or licenses, express or
 implied, are granted by Apple herein, including but not limited to any
 patent rights that may be infringed by your derivative works or by other
 works in which the Apple Software may be incorporated.
 
 The Apple Software is provided by Apple on an "AS IS" basis. APPLE MAKES
 NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE
 IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR
 A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
 OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
 
 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
 OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,
 MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED
 AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),
 STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 
 EA1002
 5/3/2013
 */

#import "UIImage+ImageEffects.h"
#import <float.h>
@import Accelerate;

@implementation UIImage (ImageEffects)


- (UIImage *)applyLightEffect{
    
    UIColor *tintColor = [UIColor colorWithWhite:1.0 alpha:0.3];
    return [self applyBlurWithRadius:30 tintColor:tintColor saturationDeltaFactor:1.8 maskImage:nil];
}


- (UIImage *)applyExtraLightEffect {
    
    UIColor *tintColor = [UIColor colorWithWhite:0.97 alpha:0.82];
    return [self applyBlurWithRadius:20 tintColor:tintColor saturationDeltaFactor:1.8 maskImage:nil];
}


- (UIImage *)applyDarkEffect {
    
    UIColor *tintColor = [UIColor colorWithWhite:0.11 alpha:0.73];
    return [self applyBlurWithRadius:20 tintColor:tintColor saturationDeltaFactor:1.8 maskImage:nil];
}


- (UIImage *)applyTintEffectWithColor:(UIColor *)tintColor {
    
    const CGFloat EffectColorAlpha = 0.6;
    UIColor      *effectColor      = tintColor;
    int           componentCount   = (int)CGColorGetNumberOfComponents(tintColor.CGColor);
    
    if (componentCount == 2) {
        
        CGFloat b;
        if ([tintColor getWhite:&b alpha:NULL]) {
            
            effectColor = [UIColor colorWithWhite:b alpha:EffectColorAlpha];
        }
        
    } else {
        
        CGFloat r, g, b;
        if ([tintColor getRed:&r green:&g blue:&b alpha:NULL]) {
            
            effectColor = [UIColor colorWithRed:r green:g blue:b alpha:EffectColorAlpha];
        }
    }
    
    return [self applyBlurWithRadius:20 tintColor:effectColor saturationDeltaFactor:1.4 maskImage:nil];
}

- (UIImage *)blurImage {
    
    return [self applyBlurWithRadius:20
                           tintColor:[UIColor colorWithWhite:0 alpha:0.0]
               saturationDeltaFactor:1.4
                           maskImage:nil];
}

- (UIImage *)blurImageWithRadius:(CGFloat)radius {
    
    return [self applyBlurWithRadius:radius
                           tintColor:[UIColor colorWithWhite:0 alpha:0.0]
               saturationDeltaFactor:1.4
                           maskImage:nil];
}

- (UIImage *)blurImageWithMask:(UIImage *)maskImage {
    
    return [self applyBlurWithRadius:20
                           tintColor:[UIColor colorWithWhite:0 alpha:0.0]
               saturationDeltaFactor:1.4
                           maskImage:maskImage];
}

- (UIImage *)blurImageAtFrame:(CGRect)frame {
    
    return [self applyBlurWithRadius:20
                           tintColor:[UIColor colorWithWhite:0 alpha:0.0]
               saturationDeltaFactor:1.4
                           maskImage:nil
                             atFrame:frame];
}

- (UIImage *)applyBlurWithRadius:(CGFloat)blurRadius tintColor:(UIColor *)tintColor saturationDeltaFactor:(CGFloat)saturationDeltaFactor maskImage:(UIImage *)maskImage {
    
    // Check pre-conditions.
    if (self.size.width < 1 || self.size.height < 1) {
        
        NSLog (@"*** error: invalid size: (%.2f x %.2f). Both dimensions must be >= 1: %@", self.size.width, self.size.height, self);
        return nil;
    }
    
    if (!self.CGImage) {
        
        NSLog (@"*** error: image must be backed by a CGImage: %@", self);
        return nil;
    }
    
    if (maskImage && !maskImage.CGImage) {
        
        NSLog (@"*** error: maskImage must be backed by a CGImage: %@", maskImage);
        return nil;
    }

    CGRect   imageRect   = { CGPointZero, self.size };
    UIImage *effectImage = self;
    
    BOOL hasBlur             = blurRadius > __FLT_EPSILON__;
    BOOL hasSaturationChange = fabs(saturationDeltaFactor - 1.) > __FLT_EPSILON__;
    if (hasBlur || hasSaturationChange) {
        
        UIGraphicsBeginImageContextWithOptions(self.size, NO, [[UIScreen mainScreen] scale]);
        CGContextRef effectInContext = UIGraphicsGetCurrentContext();
        CGContextScaleCTM(effectInContext, 1.0, -1.0);
        CGContextTranslateCTM(effectInContext, 0, -self.size.height);
        CGContextDrawImage(effectInContext, imageRect, self.CGImage);

        vImage_Buffer effectInBuffer;
        effectInBuffer.data     = CGBitmapContextGetData(effectInContext);
        effectInBuffer.width    = CGBitmapContextGetWidth(effectInContext);
        effectInBuffer.height   = CGBitmapContextGetHeight(effectInContext);
        effectInBuffer.rowBytes = CGBitmapContextGetBytesPerRow(effectInContext);
    
        UIGraphicsBeginImageContextWithOptions(self.size, NO, [[UIScreen mainScreen] scale]);
        CGContextRef effectOutContext = UIGraphicsGetCurrentContext();
        vImage_Buffer effectOutBuffer;
        effectOutBuffer.data     = CGBitmapContextGetData(effectOutContext);
        effectOutBuffer.width    = CGBitmapContextGetWidth(effectOutContext);
        effectOutBuffer.height   = CGBitmapContextGetHeight(effectOutContext);
        effectOutBuffer.rowBytes = CGBitmapContextGetBytesPerRow(effectOutContext);

        if (hasBlur) {
            
            // A description of how to compute the box kernel width from the Gaussian
            // radius (aka standard deviation) appears in the SVG spec:
            // http://www.w3.org/TR/SVG/filters.html#feGaussianBlurElement
            // 
            // For larger values of 's' (s >= 2.0), an approximation can be used: Three
            // successive box-blurs build a piece-wise quadratic convolution kernel, which
            // approximates the Gaussian kernel to within roughly 3%.
            //
            // let d = floor(s * 3*sqrt(2*pi)/4 + 0.5)
            // 
            // ... if d is odd, use three box-blurs of size 'd', centered on the output pixel.
            // 
            CGFloat inputRadius = blurRadius * [[UIScreen mainScreen] scale];
            NSUInteger radius = floor(inputRadius * 3. * sqrt(2 * M_PI) / 4 + 0.5);
            if (radius % 2 != 1) {
                
                radius += 1; // force radius to be odd so that the three box-blur methodology works.
            }
            
            vImageBoxConvolve_ARGB8888(&effectInBuffer, &effectOutBuffer, NULL, 0, 0, (uint32_t)radius, (uint32_t)radius, 0, kvImageEdgeExtend);
            vImageBoxConvolve_ARGB8888(&effectOutBuffer, &effectInBuffer, NULL, 0, 0, (uint32_t)radius, (uint32_t)radius, 0, kvImageEdgeExtend);
            vImageBoxConvolve_ARGB8888(&effectInBuffer, &effectOutBuffer, NULL, 0, 0, (uint32_t)radius, (uint32_t)radius, 0, kvImageEdgeExtend);
        }
        
        BOOL effectImageBuffersAreSwapped = NO;
        if (hasSaturationChange) {
            
            CGFloat s = saturationDeltaFactor;
            CGFloat floatingPointSaturationMatrix[] = {
                0.0722 + 0.9278 * s,  0.0722 - 0.0722 * s,  0.0722 - 0.0722 * s,  0,
                0.7152 - 0.7152 * s,  0.7152 + 0.2848 * s,  0.7152 - 0.7152 * s,  0,
                0.2126 - 0.2126 * s,  0.2126 - 0.2126 * s,  0.2126 + 0.7873 * s,  0,
                                  0,                    0,                    0,  1,
            };
            const int32_t divisor = 256;
            NSUInteger matrixSize = sizeof(floatingPointSaturationMatrix)/sizeof(floatingPointSaturationMatrix[0]);
            int16_t saturationMatrix[matrixSize];
            
            for (NSUInteger i = 0; i < matrixSize; ++i) {
                
                saturationMatrix[i] = (int16_t)roundf(floatingPointSaturationMatrix[i] * divisor);
            }
            
            if (hasBlur) {
                
                vImageMatrixMultiply_ARGB8888(&effectOutBuffer, &effectInBuffer, saturationMatrix, divisor, NULL, NULL, kvImageNoFlags);
                effectImageBuffersAreSwapped = YES;
                
            } else {
                
                vImageMatrixMultiply_ARGB8888(&effectInBuffer, &effectOutBuffer, saturationMatrix, divisor, NULL, NULL, kvImageNoFlags);
            }
        }
        
        if (!effectImageBuffersAreSwapped) {
            
            effectImage = UIGraphicsGetImageFromCurrentImageContext();
        }
        
        UIGraphicsEndImageContext();

        if (effectImageBuffersAreSwapped) {
            
            effectImage = UIGraphicsGetImageFromCurrentImageContext();
        }
        
        UIGraphicsEndImageContext();
    }

    // Set up output context.
    UIGraphicsBeginImageContextWithOptions(self.size, NO, [[UIScreen mainScreen] scale]);
    CGContextRef outputContext = UIGraphicsGetCurrentContext();
    CGContextScaleCTM(outputContext, 1.0, -1.0);
    CGContextTranslateCTM(outputContext, 0, -self.size.height);

    // Draw base image.
    CGContextDrawImage(outputContext, imageRect, self.CGImage);

    // Draw effect image.
    if (hasBlur) {
        
        CGContextSaveGState(outputContext);
        
        if (maskImage) {
            
            CGContextClipToMask(outputContext, imageRect, maskImage.CGImage);
        }
        
        CGContextDrawImage(outputContext, imageRect, effectImage.CGImage);
        CGContextRestoreGState(outputContext);
    }

    // Add in color tint.
    if (tintColor) {
        
        CGContextSaveGState(outputContext);
        CGContextSetFillColorWithColor(outputContext, tintColor.CGColor);
        CGContextFillRect(outputContext, imageRect);
        CGContextRestoreGState(outputContext);
    }

    // Output image is ready.
    UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return outputImage;
}

- (UIImage *)grayScale {
    
    int width  = self.size.width;
    int height = self.size.height;
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
    
    CGContextRef context = CGBitmapContextCreate(nil,
                                                 width,
                                                 height,
                                                 8, // bits per component
                                                 0,
                                                 colorSpace,
                                                 kCGBitmapByteOrderDefault);
    
    CGColorSpaceRelease(colorSpace);
    
    if (context == NULL) {
        
        return nil;
    }
    
    CGContextDrawImage(context,
                       CGRectMake(0, 0, width, height), self.CGImage);
    CGImageRef image   = CGBitmapContextCreateImage(context);
    UIImage *grayImage = [UIImage imageWithCGImage:image];
    CFRelease(image);
    CGContextRelease(context);
    
    return grayImage;
}

- (UIImage *)scaleWithFixedWidth:(CGFloat)width {
    
    float newHeight = self.size.height * (width / self.size.width);
    CGSize size     = CGSizeMake(width, newHeight);
    UIGraphicsBeginImageContextWithOptions(size, NO, 0);
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    CGContextTranslateCTM(context, 0.0, size.height);
    CGContextScaleCTM(context, 1.0, -1.0);
    
    CGContextSetBlendMode(context, kCGBlendModeCopy);
    CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, size.width, size.height), self.CGImage);
    
    UIImage *imageOut = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return imageOut;
}

- (UIImage *)scaleWithFixedHeight:(CGFloat)height {
    
    float newWidth = self.size.width * (height / self.size.height);
    CGSize size    = CGSizeMake(newWidth, height);
    
    UIGraphicsBeginImageContextWithOptions(size, NO, 0);
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    CGContextTranslateCTM(context, 0.0, size.height);
    CGContextScaleCTM(context, 1.0, -1.0);
    
    CGContextSetBlendMode(context, kCGBlendModeCopy);
    CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, size.width, size.height), self.CGImage);
    
    UIImage *imageOut = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return imageOut;
}

- (UIColor *)averageColor {
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    unsigned char rgba[4];
    CGContextRef context = CGBitmapContextCreate(rgba, 1, 1, 8, 4, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
    
    CGContextDrawImage(context, CGRectMake(0, 0, 1, 1), self.CGImage);
    CGColorSpaceRelease(colorSpace);
    CGContextRelease(context);
    
    if(rgba[3] > 0) {
        CGFloat alpha = ((CGFloat)rgba[3])/255.0;
        CGFloat multiplier = alpha/255.0;
        return [UIColor colorWithRed:((CGFloat)rgba[0])*multiplier
                               green:((CGFloat)rgba[1])*multiplier
                                blue:((CGFloat)rgba[2])*multiplier
                               alpha:alpha];
    }
    else {
        return [UIColor colorWithRed:((CGFloat)rgba[0])/255.0
                               green:((CGFloat)rgba[1])/255.0
                                blue:((CGFloat)rgba[2])/255.0
                               alpha:((CGFloat)rgba[3])/255.0];
    }
}

- (UIImage *)croppedImageAtFrame:(CGRect)frame {
    
    frame = CGRectMake(frame.origin.x * self.scale,
                       frame.origin.y * self.scale,
                       frame.size.width * self.scale,
                       frame.size.height * self.scale);
    
    CGImageRef sourceImageRef = [self CGImage];
    CGImageRef newImageRef    = CGImageCreateWithImageInRect(sourceImageRef, frame);
    UIImage   *newImage       = [UIImage imageWithCGImage:newImageRef scale:[self scale] orientation:[self imageOrientation]];
    CGImageRelease(newImageRef);
    return newImage;
}

- (UIImage *)addImageToImage:(UIImage *)img atRect:(CGRect)cropRect {
    
    CGSize size = CGSizeMake(self.size.width, self.size.height);
    UIGraphicsBeginImageContextWithOptions(size, NO, self.scale);
    
    CGPoint pointImg1 = CGPointMake(0,0);
    [self drawAtPoint:pointImg1];
    
    CGPoint pointImg2 = cropRect.origin;
    [img drawAtPoint: pointImg2];
    
    UIImage* result = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return result;
}

- (UIImage *)applyBlurWithRadius:(CGFloat)blurRadius
                       tintColor:(UIColor *)tintColor
           saturationDeltaFactor:(CGFloat)saturationDeltaFactor
                       maskImage:(UIImage *)maskImage
                         atFrame:(CGRect)frame
{
    UIImage *blurredFrame = \
    [[self croppedImageAtFrame:frame] applyBlurWithRadius:blurRadius
                                                tintColor:tintColor
                                    saturationDeltaFactor:saturationDeltaFactor
                                                maskImage:maskImage];
    
    return [self addImageToImage:blurredFrame atRect:frame];
}

@end



2014-09-19 15:12:26 xin814 阅读数 4710
  
    typedef NS_ENUM(NSInteger, UIBlurEffectStyle) {
    UIBlurEffectStyleExtraLight,
    UIBlurEffectStyleLight,
    UIBlurEffectStyleDark
} NS_ENUM_AVAILABLE_IOS(8_0);


    UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];
    UIVisualEffectView *blurEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
    blurEffectView.frame = self.imageView.bounds;
    [self.imageView insertSubview:blurEffectView atIndex:0];
 


未处理效果



UIBlurEffectStyleLight


UIBlurEffectStyleExtraLight



UIBlurEffectStyleDark

iOS 图片模糊效果

阅读数 218

iOS8带来了更多好玩的API。

博文 来自: oShuiJue
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