调用这个方法，传入你想要屏幕截图的最外层ViewGroup:

public Bitmap screenShot(View view) {
    Bitmap bitmap = Bitmap.createBitmap(view.getWidth(),
            view.getHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    view.draw(canvas);
    return bitmap;
}

作为参考，捕获屏幕(而不仅仅是应用程序活动)的一种方法是捕获帧缓冲区(device /dev/graphics/fb0)。要做到这一点，你必须拥有根权限，或者你的应用程序必须是一个具有签名权限的应用程序(“只有当请求应用程序与声明该权限的应用程序使用相同的证书进行签名时，系统才授予该权限”)-这是不太可能的，除非你编译了自己的ROM。

我测试过的几个设备上的每个framebuffer捕获都只包含一个截图。人们报告它包含更多，我猜这取决于框架/显示尺寸。

我尝试连续读取framebuffer，但它似乎返回了固定数量的读取字节。在我的例子中，这是(3 410 432)字节，这足以存储854*480 RGBA(3 279 360字节)的显示帧。是的，帧，二进制，从fb0输出是RGBA在我的设备。这很可能取决于不同的设备。这对你解码它很重要=)

在我的设备/dev/graphics/fb0权限是这样的，只有root和组图形的用户可以读取fb0。

图形是一个受限制的组，所以您可能只能使用su命令在根机中访问fb0。

Android应用程序的用户id (uid) = app_##，组id (guid) = app_##。

adb shell有uid = shell和guid = shell，它们拥有比app更多的权限。你可以在/system/permissions/platform.xml中查看这些权限

这意味着你将能够在没有根的adb shell中读取fb0，但如果没有根，你将无法在应用中读取它。

同样，在AndroidManifest.xml上给予READ_FRAME_BUFFER和/或ACCESS_SURFACE_FLINGER权限对常规应用没有任何作用，因为这些只对“签名”应用有效。

也检查这个关闭线程的更多细节。

这个问题的大多数答案使用Canvas绘图方法或绘图缓存方法。然而，View.setDrawingCache()方法在API 28中已弃用。目前，用于制作截图的推荐API是API 24提供的PixelCopy类(但接受Window参数的方法可从API 26 == Android 8.0 Oreo获得)。下面是一个检索位图的示例Kotlin代码:

@RequiresApi(Build.VERSION_CODES.O)
fun saveScreenshot(view: View) {
    val window = (view.context as Activity).window
    if (window != null) {
        val bitmap = Bitmap.createBitmap(view.width, view.height, Bitmap.Config.ARGB_8888)
        val locationOfViewInWindow = IntArray(2)
        view.getLocationInWindow(locationOfViewInWindow)
        try {
            PixelCopy.request(window, Rect(locationOfViewInWindow[0], locationOfViewInWindow[1], locationOfViewInWindow[0] + view.width, locationOfViewInWindow[1] + view.height), bitmap, { copyResult ->
                if (copyResult == PixelCopy.SUCCESS) {
                    saveBitmap(bitmap)
                }
                // possible to handle other result codes ...
            }, Handler())
        } catch (e: IllegalArgumentException) {
            // PixelCopy may throw IllegalArgumentException, make sure to handle it
        }
    }
}

public class ScreenShotActivity extends Activity{

private RelativeLayout relativeLayout;
private Bitmap myBitmap;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    relativeLayout = (RelativeLayout)findViewById(R.id.relative1);
    relativeLayout.post(new Runnable() {
        public void run() {

            //take screenshot
            myBitmap = captureScreen(relativeLayout);

            Toast.makeText(getApplicationContext(), "Screenshot captured..!", Toast.LENGTH_LONG).show();

            try {
                if(myBitmap!=null){
                    //save image to SD card
                    saveImage(myBitmap);
                }
                Toast.makeText(getApplicationContext(), "Screenshot saved..!", Toast.LENGTH_LONG).show();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }
    });

}

public static Bitmap captureScreen(View v) {

    Bitmap screenshot = null;
    try {

        if(v!=null) {

            screenshot = Bitmap.createBitmap(v.getMeasuredWidth(),v.getMeasuredHeight(), Config.ARGB_8888);
            Canvas canvas = new Canvas(screenshot);
            v.draw(canvas);
        }

    }catch (Exception e){
        Log.d("ScreenShotActivity", "Failed to capture screenshot because:" + e.getMessage());
    }

    return screenshot;
}

public static void saveImage(Bitmap bitmap) throws IOException{

    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.PNG, 40, bytes);
    File f = new File(Environment.getExternalStorageDirectory() + File.separator + "test.png");
    f.createNewFile();
    FileOutputStream fo = new FileOutputStream(f);
    fo.write(bytes.toByteArray());
    fo.close();
}

}

添加权限

< uses-permission android: name = " android.permission.WRITE_EXTERNAL_STORAGE " / >

我的解决方案是:

public static Bitmap loadBitmapFromView(Context context, View v) {
    DisplayMetrics dm = context.getResources().getDisplayMetrics(); 
    v.measure(MeasureSpec.makeMeasureSpec(dm.widthPixels, MeasureSpec.EXACTLY),
            MeasureSpec.makeMeasureSpec(dm.heightPixels, MeasureSpec.EXACTLY));
    v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());
    Bitmap returnedBitmap = Bitmap.createBitmap(v.getMeasuredWidth(),
            v.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(returnedBitmap);
    v.draw(c);

    return returnedBitmap;
}

and

public void takeScreen() {
    Bitmap bitmap = ImageUtils.loadBitmapFromView(this, view); //get Bitmap from the view
    String mPath = Environment.getExternalStorageDirectory() + File.separator + "screen_" + System.currentTimeMillis() + ".jpeg";
    File imageFile = new File(mPath);
    OutputStream fout = null;
    try {
        fout = new FileOutputStream(imageFile);
        bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fout);
        fout.flush();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        fout.close();
    }
}

图像保存在外部存储文件夹中。

仅限系统应用!

Process process;
process = Runtime.getRuntime().exec("screencap -p " + outputPath);
process.waitFor();

注意:系统应用不需要执行“su”命令执行该命令。