Android当前任务管理器不显示应用进程

Android框架为我们维护了一个名叫“最近运行”的应用程序列表，以方便进行应用程序切换。

它是通过ActivityManifest.xml中的activity标签定义了一个这样的属性。

• excludeFromRecents

  该属性表示应用程序是否应该将Activity从最近运行的应用程序列表排除。android:excludeFromRecents=”true”—表示排除，反之不排除。默认值为false。这个属性的前提是该Activity是某个任务的根Activity。

看下面代码：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.yiba.test.test">
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:excludeFromRecents="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".SecondActivity" />
        <activity
            android:name=".ThirdActivity"
            android:excludeFromRecents="true"
            android:launchMode="singleInstance" />
    </application>
</manifest>

Activity的跳转步骤

MainActivity–>SecondActivity–>ThirdActivity(启动模式singleInstatce)。

• MainActivity

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn = (Button) findViewById(R.id.btn);
        TextView text = (TextView) findViewById(R.id.text);
        text.setText(getClass().getSimpleName());
        btn.setText("跳转到SecondActivity");
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(getApplicationContext(), SecondActivity.class));
            }
        });
    }
}

• SecondActivity

public class SecondActivity extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView text = (TextView) findViewById(R.id.text);
        text.setText(getClass().getSimpleName());
        Button btn = (Button) findViewById(R.id.btn);
        btn.setText("跳转到ThirdActivity");
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(getApplicationContext(), ThirdActivity.class));
            }
        });
    }
}

• ThridActivity

public class ThirdActivity extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView text = (TextView) findViewById(R.id.text);
        text.setText(getClass().getSimpleName());
    }
}

显示的效果：