从Android 11 (API级别30)，你可以用辅助服务截屏:

takeScreenshot -截取指定显示的屏幕截图，并通过AccessibilityService.ScreenshotResult返回。

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 " / >

如果你想捕捉一个视图或布局，比如RelativeLayout或LinearLayout等。

只需使用代码:

LinearLayout llMain = (LinearLayout) findViewById(R.id.linearlayoutMain);
Bitmap bm = loadBitmapFromView(llMain);

现在你可以保存这个位图在设备存储:

FileOutputStream outStream = null;
File f=new File(Environment.getExternalStorageDirectory()+"/Screen Shots/");
f.mkdir();
String extStorageDirectory = f.toString();
File file = new File(extStorageDirectory, "my new screen shot");
pathOfImage = file.getAbsolutePath();
try {
    outStream = new FileOutputStream(file);
    bm.compress(Bitmap.CompressFormat.PNG, 100, outStream);
    Toast.makeText(getApplicationContext(), "Saved at "+f.getAbsolutePath(), Toast.LENGTH_LONG).show();
    addImageGallery(file);
    //mail.setEnabled(true);
    flag=true;
} catch (FileNotFoundException e) {e.printStackTrace();}
try {
    outStream.flush();
    outStream.close();
} catch (IOException e) {e.printStackTrace();}

private void captureScreen() {
    View v = getWindow().getDecorView().getRootView();
    v.setDrawingCacheEnabled(true);
    Bitmap bmp = Bitmap.createBitmap(v.getDrawingCache());
    v.setDrawingCacheEnabled(false);
    try {
        FileOutputStream fos = new FileOutputStream(new File(Environment
                .getExternalStorageDirectory().toString(), "SCREEN"
                + System.currentTimeMillis() + ".png"));
        bmp.compress(CompressFormat.PNG, 100, fos);
        fos.flush();
        fos.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

在清单中添加权限

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

对于支持棉花糖或以上版本，请在onCreate方法中添加以下代码

ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},00);

对于整页滚动截图

如果你想要捕捉一个完整的视图截图(其中包含一个滚动视图左右)，那么在这个库中进行检查

https://github.com/peter1492/LongScreenshot

你所要做的就是导入Gradel，并创建一个bigscreen的对象

长截图=新BigScreenshot(这个，x, y);

当自动滚动屏幕视图组并在最后组装在一起时，将接收回调的屏幕截图位图。

get截图(Bitmap) {}

哪些可以保存到画廊或任何必要的用途，他们之后

这个方法不需要root权限，也不需要大量编码。

在adb shell上使用以下命令可以截屏。

input keyevent 120

这个命令不需要任何root权限，所以你也可以从android应用程序的java代码执行。

Process process;
process = Runtime.getRuntime().exec("input keyevent 120");

更多关于android中的keyevent代码，请参阅http://developer.android.com/reference/android/view/KeyEvent.html

这里我们用了。KEYCODE_SYSRQ，它的值是120，用于系统请求/打印屏幕键。

如CJBS所说，输出的图片将保存在/sdcard/Pictures/Screenshots