DialogFragment如何设置大小和位置

getDialog().getWindow().setGravity(Gravity.CENTER_HORIZONTAL | Gravity.BOTTOM);
WindowManager.LayoutParams lp = getDialog().getWindow().getAttributes();
lp.width = WindowManager.LayoutParams.MATCH_PARENT;
if (mHeight == 0) {
lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
} else {
lp.height = mHeight;
}
getDialog().getWindow().setAttributes(lp);