Java以编程方式在LinearLayout中设置边距

这是一些实现它的代码：

LinearLayout ll = new LinearLayout(this);ll.setOrientation(LinearLayout.VERTICAL);LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(     LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);layoutParams.setMargins(30, 20, 30, 0);Button okButton=new Button(this);okButton.setText("some text");ll.addView(okButton, layoutParams);