如何在Android 5.0或sdk >21中截屏

Question

正如你所知道的，如果设备是根的，你可以用代码截屏

Process sh = Runtime.getRuntime().exec("su", null,null);
OutputStream  os = sh.getOutputStream();
os.write(("/system/bin/screencap -p " + "/sdcard/img.png").getBytes("ASCII"));
os.flush();
os.close();
sh.waitFor();

但对于SDK>21 (5.0或更高版本)，它不支持此功能。所以，我想知道如何使用Android 5.0或更高版本的服务(另一个应用程序)截屏。

我看到了MediaProjectionManager，但它需要运行onActivityResult来接收结果，但在服务中，它不能激活。

Answer 1

这将为您提供:在您的类文件中全局声明它-

私有文件imageFile；私有void takeScreenshot() {

    try {
        String mPath = Environment.getExternalStorageDirectory().toString() +"\\/pic";            View v1 = FirstScreenActivity.mActivity.getWindow().getDecorView().getRootView();
        v1.setDrawingCacheEnabled(true);
        Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
        v1.setDrawingCacheEnabled(false);

        imageFile = new File(mPath);

        FileOutputStream outputStream = new FileOutputStream(imageFile);
        int quality = 100;
        bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
        outputStream.flush();
        outputStream.close();
    } catch (Throwable e) {
        e.printStackTrace();
    }

Answer 2

首先在您的activity类中添加一个Activity对象，如下所示-

public class FirstScreenActivity extends AppCompatActivity {

public static Activity mActivity;
private File imageFile;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mActivity=this;
}

@Override
protected void onResume() {
    super.onResume();}

然后在您的非活动类文件中使用静态mActivity，如下所示，在前面的答案中使用上面的代码：

View v1 = FirstScreenActivity.mActivity.getWindow().getDecorView().getRootView();

Answer 3

以下是要在清单文件中指定的接收者-

<receiver android:name=".reciever.EventReceiver">
        <intent-filter >
            <action android:name="android.provider.Telephony.SMS_RECEIVED" />
            <action android:name="android.intent.action.USER_PRESENT"/>
        </intent-filter>
    </receiver>

像这些动作一样，你也可以选择其他动作。注意：不要忘记为您将在receiver中使用的操作添加权限。这是receiver类，您将在其中编写代码(在本例中为截图)-

public class EventReceiver  extends BroadcastReceiver {
private File imageFile;
private Context mContext;

@Override
public void onReceive(final Context context, Intent intent) {
    mContext=context;
    takeScreenshot();
//you can execute some of your other code also

}
private void takeScreenshot() {
    try {
        String mPath = Environment.getExternalStorageDirectory().toString() +"\\/pic";
        View v1 = FirstScreenActivity.mActivity.getWindow().getDecorView().getRootView();
        v1.setDrawingCacheEnabled(true);
        Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
        v1.setDrawingCacheEnabled(false);

        imageFile = new File(mPath);

        FileOutputStream outputStream = new FileOutputStream(imageFile);
        int quality = 100;
        bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
        outputStream.flush();
        outputStream.close();
    } catch (Throwable e) {
        e.printStackTrace();
    }
}

}

使用它，您的接收器类的onReceive()将在您在清单中指定的特定事件操作上执行。