Dialog 用代码来实现全屏

实现代码如下

Window window = getWindow();
requestWindowFeature(Window.FEATURE_NO_TITLE);
if (window != null) {
window.getDecorView().setPadding(0, 0, 0, 0);
//很重要         window.setBackgroundDrawableResource(android.R.color.transparent);
WindowManager.LayoutParams params = window.getAttributes();
params.width = ViewGroup.LayoutParams.MATCH_PARENT;
params.height = ViewGroup.LayoutParams.MATCH_PARENT;
window.setAttributes(params);
}