自定义布局绘制画布失败

Question

I'm using the custom layout for arranging the views , while converting my view to bitmap it is not drawing it child views on the bitmap.Please help me to get rid out of this problem here is my code

public class CustomLayout extends ViewGroup {
private int line_height;    
public CustomLayout(Context context) {
    super(context);      
   this.setWillNotDraw(false);              
}                    

public CustomLayout(Context context, AttributeSet attrs)
{
    super(context, attrs);
}            

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    assert(MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);

    final int width = MeasureSpec.getSize(widthMeasureSpec);

    // The next line is WRONG!!! Doesn't take into account requested MeasureSpec mode!
    int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
    final int count = getChildCount();
    int line_height = 0;

    int xpos = getPaddingLeft();
    int ypos = getPaddingTop();

    for (int i = 0; i < count; i++) {
        final View child = getChildAt(i);
        if (child.getVisibility() != GONE) {
            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
            child.measure(
                    MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST),
                    MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST));

            final int childw = child.getMeasuredWidth();
            line_height = Math.max(line_height, child.getMeasuredHeight() + lp.height);

            if (xpos + childw > width) {
                xpos = getPaddingLeft();
                ypos += line_height;
            }

            xpos += childw + lp.width;
        }

    }
    this.line_height = line_height;

    if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED){
        height = ypos + line_height;

    } else if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST){
        if (ypos + line_height < height){
            height = ypos + line_height;
        }

    }

    setMeasuredDimension(width, height);
}

@Override
protected LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(1, 1); // default of 1px spacing
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {

    final int count = getChildCount();
    final int width = r - l;
    int xpos = getPaddingLeft();
    int ypos = getPaddingTop()-10;

    /**
     * padding
     */
    //int padding = 10;

    for (int i = 0; i < count; i++) {
        final View child = getChildAt(i);
        if(child instanceof CheckBox)
        {
            CheckBox chk = (CheckBox)child;
            Log.e("APPLAYOYUTTTTTT", String.valueOf(chk.getText()));
        }
        if (child.getVisibility() != GONE) {
            final int childw = child.getMeasuredWidth();
            final int childh = child.getMeasuredHeight();
            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
            if (xpos + childw > width) {
                xpos = getPaddingLeft();
                ypos += line_height;
            }

            child.layout(xpos, ypos, xpos + childw, ypos + childh);

            xpos += childw + lp.width  ;//+ padding;
            child.buildDrawingCache(true);
            child.setWillNotDraw(true);
        }
    }



}
 }

Button that converts view to bitmap

    btnViewBitmap.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            View v = lp; // custom layout object.

            v.measure(825, LayoutParams.WRAP_CONTENT);              
            v.setBackgroundColor(Color.TRANSPARENT);

            Bitmap b = Bitmap.createBitmap(825, 1140, Bitmap.Config.ARGB_8888);
            Canvas c = new Canvas(b);
            v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());


                v.draw(c);                 
                FileOutputStream out;
                try {
                    out = new FileOutputStream("/mnt/sdcard/ViewBitmap.png");
                    b.compress(Bitmap.CompressFormat.PNG, 90, out);
                    b.recycle();
                    try {
                        out.flush();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    try {
                        out.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }  
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }


        }
    });

Answer 1

做child.setWillNotDraw（true），很可能会跳过子视图的绘制。