如何将视图转换为位图

FrameLayout view = (FrameLayout)findViewById(R.id.framelayout);
view.setDrawingCacheEnabled(true);
view.buildDrawingCache();
Bitmap bm = view.getDrawingCache();

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我曾经使用buildDrawingCache()方法来获取布局的位图，但是当视图很大时使用I was having trouble with it。现在我使用以下方法：

FrameLayout view = findViewById(R.id.framelayout);
Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
view.draw(canvas);

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你可以使用下面的代码片段得到一个视图的位图

mView.setDrawingCacheEnabled(true);
mView.getDrawingCache();

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为什么不写一个扩展ImageView的类，重写方法onDraw，把你的图片和文本放在那里，这样更容易

首先，您需要添加依赖项

implementation 'com.github.vipulasri.layouttoimage:library:1.0.0'

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然后将布局转换为位图

RelativeLayout pdfmain;
Layout_to_Image layout_to_image;
Bitmap mBitmap;
    layout_to_image = new Layout_to_Image(AllotmentDoc.this, pdfmain);
    mBitmap = layout_to_image.convert_layout();

型

FrameLayout v = (FrameLayout)findViewById(R.id.frme1);
    v.setDrawingCacheEnabled(true);
    // this is the important code :)
  // Without it the view will have a dimension of 0,0 and the bitmap will be null
    v.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),
            View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
    v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());
    v.buildDrawingCache(true);
    v.post(new Runnable() {
        @Override
        public void run() {
           // Bitmap b = v.getDrawingCache();
            Bitmap b = Bitmap.createBitmap(v.getDrawingCache());
            v.setDrawingCacheEnabled(false); // clear drawing cache
            Log.e("ss","ss"+b.getHeight());
        }
    });

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在这里我添加了一个post Runnable线程，它确保Bitmap方法只在v.buildDrawingCache（true）;. v.buildDrawingCache（true）;在某些移动的中需要几毫秒的时间后才执行，这就是它在某些移动的中崩溃的原因。如果您遇到Bitmap对象的空指针异常，请尝试此解决方案。

public static Bitmap loadBitmapFromView(View view) {
    view.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED), View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
    view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
    final Bitmap bitmap = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    view.draw(canvas);
    return bitmap;
}

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