如何在安卓自定义ViewGroup上调用setMargins()；？

public class CustomViewGroup extends ViewGroup {
    // 构造函数
    public CustomViewGroup(Context context) {
        super(context);
    }

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

    public CustomViewGroup(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    // 重写onLayout方法
    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        // 在这里设置子View的位置
        int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            View childView = getChildAt(i);
            // 设置子View的位置
            childView.layout(left, top, right, bottom);
        }
    }
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    // 测量子View的大小
    int childCount = getChildCount();
    for (int i = 0; i < childCount; i++) {
        View childView = getChildAt(i);
        // 测量子View的大小
        measureChild(childView, widthMeasureSpec, heightMeasureSpec);
    }

    // 设置自定义ViewGroup的大小
    setMeasuredDimension(MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.getSize(heightMeasureSpec));
}

// 创建自定义ViewGroup的实例
CustomViewGroup customViewGroup = new CustomViewGroup(context);

// 创建子View
View childView = new View(context);
// 设置子View的布局参数
CustomViewGroup.LayoutParams layoutParams = new CustomViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
// 设置子View的边距
layoutParams.setMargins(leftMargin, topMargin, rightMargin, bottomMargin);
// 添加子View到自定义ViewGroup中
customViewGroup.addView(childView, layoutParams);