2013.8.6 inflate View，convertViewToBitMap() 时NullPointException的问题

1，RelativeLayout mPopView = (RelativeLayout) View.inflate(mContext, R.layout.show_pop, null);

private Bitmap convertViewToBitmap(RelativeLayout view) {
		view.setLayoutParams(new LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT));
		view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
				MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
		view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
		view.buildDrawingCache();
		Bitmap bitmap = view.getDrawingCache();

		return bitmap;
	}

在convertViewToBitMap()方法中加入

view.setLayoutParams(new LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT));

前，在view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),报NullPointException，加入那句后正常了。

在stackoverflow上得知

Inflater does not extract layout_width and layout_height attributes when you don't assign its parent as an argument in inflate method, so try to set LayoutParams with specified width and height and then call measure.

参考：http://stackoverflow.com/questions/5940150/null-pointer-exception-when-calling-measure-on-inflated-layout