Question

我需要将视图转换为位图以预览我的视图并将其另存为图像。我尝试使用以下代码，但它创建了一个空白图像。我无法理解我犯了什么错误。

 View viewToBeConverted;  Bitmap viewBitmap =   Bitmap.createBitmap(viewToBeConverted.getWidth(), viewToBeConverted.getHeight(),Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(viewBitmap); 
 viewToBeConverted.draw(canvas); 
 savephoto(“f1”, viewBitmap); 

 ////  public void savephoto(String filename,Bitmap bit)     
   {  
            File newFile = new File(Environment.getExternalStorageDirectory() + Picture_Card/"+ filename+ ".PNG");
              try 
{
                    newFile.createNewFile();                   
 try
 { 
                         FileOutputStream pdfFile = new FileOutputStream(newFile);                                                Bitmap bm = bit;                          ByteArrayOutputStream baos = new ByteArrayOutputStream();                          bm.compress(Bitmap.CompressFormat.PNG,100, baos);                                                     byte[] bytes = baos.toByteArray();                         
 pdfFile.write(bytes);                                              
      pdfFile.close();                   
 }
 catch (FileNotFoundException e) 
{                          //       

  }            
  } catch (IOException e)
 {                    //          
    }      
  }

Answer 1

这是我的解决方案：

  public static Bitmap getBitmapFromView(View view) {
        //Define a bitmap with the same size as the view
        Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(),Bitmap.Config.ARGB_8888);
        //Bind a canvas to it
        Canvas canvas = new Canvas(returnedBitmap);
        //Get the view's background
        Drawable bgDrawable =view.getBackground();
        if (bgDrawable!=null) 
            //has background drawable, then draw it on the canvas
            bgDrawable.draw(canvas);
        else 
            //does not have background drawable, then draw white background on the canvas
            canvas.drawColor(Color.WHITE);
        // draw the view on the canvas
        view.draw(canvas);
        //return the bitmap
        return returnedBitmap;
    }

享受：）

Answer 2

投票最多的解决方案对我不起作用，因为我的视图是ViewGroup（已从LayoutInflater中膨胀）。我需要调用view.measure来强制计算视图大小，以便使用view.getMeasuredWidth（Height）获得正确的视图大小。

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

Answer 3

使用新的kotlin提取函数view.drawToBitmap()

mLayout.drawToBitmap()

Answer 4

使用画布上的绘图的所有答案都不适用于GLSurfaceView。

要将GLSurfaceView的内容捕获到位图中，您应该考虑在gl.glReadPixels内使用Renderer::onDrawFrame()实现自定义方法。

已发布解决方案代码段here。

Answer 5

以下是受Google Android Maps Utils Icon Generator启发的Kotlin扩展名

fun View.convertToBitmap(): Bitmap {
val measureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED)
measure(measureSpec, measureSpec)
layout(0, 0, measuredWidth, measuredHeight)
val r = Bitmap.createBitmap(measuredWidth, measuredHeight, Bitmap.Config.ARGB_8888)
r.eraseColor(Color.TRANSPARENT)
val canvas = Canvas(r)
draw(canvas)
return r }

Answer 6

将布局或视图转换为位图：

  private Bitmap createBitmapFromLayout(View tv) {        
    int spec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    tv.measure(spec, spec);
    tv.layout(0, 0, tv.getMeasuredWidth(), tv.getMeasuredHeight());
    Bitmap b = Bitmap.createBitmap(tv.getMeasuredWidth(), tv.getMeasuredWidth(),
            Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);
    c.translate((-tv.getScrollX()), (-tv.getScrollY()));
    tv.draw(c);
    return b;
}

没有xml：

  private Bitmap createBitmapFromView() {
    TextView tv = new TextView(this);
    tv.setText("Hello Android !!");
    tv.setTextColor(Color.WHITE);
    tv.setBackgroundColor(Color.GRAY);
    int spec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    tv.measure(spec, spec);
    tv.layout(0, 0, tv.getMeasuredWidth(), tv.getMeasuredHeight());
    Bitmap b = Bitmap.createBitmap(tv.getMeasuredWidth(), tv.getMeasuredWidth(),
            Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);
    c.translate((-tv.getScrollX()), (-tv.getScrollY()));
    tv.draw(c);
    return b;
}

在Android上将视图转换为位图

6 个答案: