java - 无法将包含所有内容的相对布局转换为图像

Question

我有一个具有 ScrollView 和超过 20 个 TextView 的相对布局。当我尝试将此布局转换为位图时，它没有发生当我在外部存储中查看它时，它说“此文件已损坏”在图库中，图像显示黑色 View

这是我用来将 View 转换为位图的代码

public static Bitmap loadBitmapFromView(Context context, View v) {

DisplayMetrics dm = context.getResources().getDisplayMetrics();
v.measure(View.MeasureSpec.makeMeasureSpec(dm.widthPixels, View.MeasureSpec.UNSPECIFIED),
        View.MeasureSpec.makeMeasureSpec(dm.heightPixels, View.MeasureSpec.UNSPECIFIED));
v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());

Bitmap bitmap = Bitmap.createBitmap(v.getMeasuredWidth(),
        v.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bitmap);
v.draw(c);

return bitmap;
     }

我已经将相对布局的对象传递给了loadBitmapFromView。

和我已经使用此代码将图像保存到外部存储

     private void SaveImage(Bitmap finalBitmap) {


String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 100000;
n = generator.nextInt(n);
String fname = "Image-"+ n +".jpg";
File file = new File (myDir, fname);
if (file.exists ()) file.delete ();
try {
    FileOutputStream out = new FileOutputStream(file);
    finalBitmap.compress(Bitmap.CompressFormat.JPEG,1000,out);
    out.flush();
    out.close();
} catch (Exception e) {
    e.printStackTrace();
}
   }

这是我的日志

12-30 15:02:20.397 24825-24825/com.google.android.gms.samples.vision.barcodereader W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
12-30 15:02:20.397 24825-24825/com.google.android.gms.samples.vision.barcodereader W/System.err:     at com.google.android.gms.samples.vision.barcodereader.ResultActivity.SaveImage(ResultActivity.java:3483)
12-30 15:02:20.397 24825-24825/com.google.android.gms.samples.vision.barcodereader W/System.err:     at com.google.android.gms.samples.vision.barcodereader.ResultActivity.onCreate(ResultActivity.java:137)

Answer 1

您的 createBitmap 函数将返回 null，您尝试获取如下位图。

final View v = mView.findViewById(R.id.your_view_id);
Bitmap b = Bitmap.createBitmap( v.getMeasuredWidth(),
                v.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
v.layout(v.getLeft(), v.getTop(), v.getRight(), v.getBottom());
v.draw(c);
return b;