如何通过代码而不是程序来截取手机屏幕的选定区域的截图?


当前回答

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
        }
    }
}

其他回答

Mualig的回答很好,但我遇到了Ewoks描述的同样的问题,我没有得到背景。所以有时已经足够好了,有时我得到黑色背景上的黑色文本(取决于主题)。

这个解决方案主要基于Mualig代码和我在Robotium中找到的代码。通过直接调用draw方法,我放弃了绘图缓存的使用。在此之前,我将尝试从当前活动中首先绘制背景。

// Some constants
final static String SCREENSHOTS_LOCATIONS = Environment.getExternalStorageDirectory().toString() + "/screenshots/";

// Get device dimmensions
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);

// Get root view
View view = mCurrentUrlMask.getRootView();

// Create the bitmap to use to draw the screenshot
final Bitmap bitmap = Bitmap.createBitmap(size.x, size.y, Bitmap.Config.ARGB_4444);
final Canvas canvas = new Canvas(bitmap);

// Get current theme to know which background to use
final Activity activity = getCurrentActivity();
final Theme theme = activity.getTheme();
final TypedArray ta = theme
    .obtainStyledAttributes(new int[] { android.R.attr.windowBackground });
final int res = ta.getResourceId(0, 0);
final Drawable background = activity.getResources().getDrawable(res);

// Draw background
background.draw(canvas);

// Draw views
view.draw(canvas);

// Save the screenshot to the file system
FileOutputStream fos = null;
try {
    final File sddir = new File(SCREENSHOTS_LOCATIONS);
    if (!sddir.exists()) {
        sddir.mkdirs();
    }
    fos = new FileOutputStream(SCREENSHOTS_LOCATIONS
            + System.currentTimeMillis() + ".jpg");
    if (fos != null) {
        if (!bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos)) {
            Log.d(LOGTAG, "Compress/Write failed");
        }
        fos.flush();
        fos.close();
    }

} catch (FileNotFoundException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (IOException e) {
    // TODO Auto-generated catch block
    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);

参数视图是根布局对象。

public static Bitmap screenShot(View view) {
                    Bitmap bitmap = null;
                    if (view.getWidth() > 0 && view.getHeight() > 0) {
                        bitmap = Bitmap.createBitmap(view.getWidth(),
                                view.getHeight(), Bitmap.Config.ARGB_8888);
                        Canvas canvas = new Canvas(bitmap);
                        view.draw(canvas);
                    }
                    return bitmap;
                }

下面是允许我的截图存储在SD卡上的代码,以后无论你需要什么都可以使用:

首先,你需要添加一个适当的权限来保存文件:

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

这是代码(运行在一个活动中):

private void takeScreenshot() {
    Date now = new Date();
    android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss", now);

    try {
        // image naming and path  to include sd card  appending name you choose for file
        String mPath = Environment.getExternalStorageDirectory().toString() + "/" + now + ".jpg";

        // create bitmap screen capture
        View v1 = getWindow().getDecorView().getRootView();
        v1.setDrawingCacheEnabled(true);
        Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
        v1.setDrawingCacheEnabled(false);

        File imageFile = new File(mPath);

        FileOutputStream outputStream = new FileOutputStream(imageFile);
        int quality = 100;
        bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
        outputStream.flush();
        outputStream.close();

        openScreenshot(imageFile);
    } catch (Throwable e) {
        // Several error may come out with file handling or DOM
        e.printStackTrace();
    }
}

这是你如何打开最近生成的图像:

private void openScreenshot(File imageFile) {
    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_VIEW);
    Uri uri = Uri.fromFile(imageFile);
    intent.setDataAndType(uri, "image/*");
    startActivity(intent);
}

如果你想在片段视图上使用这个,那么使用:

View v1 = getActivity().getWindow().getDecorView().getRootView();

而不是

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

on takeScreenshot()函数

注意:

如果对话框包含一个表面视图,这个解决方案就不起作用。详情请查看以下问题的答案:

Android界面截图显示黑屏

如果你想捕捉一个视图的截图,使用View::drawToBitmap扩展函数:

val bitmap = myTargetView.drawToBitmap(/*Optional:*/ Bitmap.Config.ARGB_8888)

只需要确保使用-ktx版本的AndroidX核心库:

implementation("androidx.core:core-ktx:1.6.0")

我已经回答过一个类似的问题。