为此使用委托事件处理.
这是适合您的示例示例.

在Site.Master.cs

Use delegate event handling for this.
Here is sample example for you.

In Site.Master.cs

public delegate void DoEvent();

        public event DoEvent OnDoEvent;

        protected void Button1_Click(object sender, EventArgs e)
        {
            if (OnDoEvent != null)
            {
                OnDoEvent();
            }
        }

在Default.aspx.cs中

in Default.aspx.cs

protected void Page_Load(object sender, EventArgs e)
        {
            (this.Master as SiteMaster).OnDoEvent += new SiteMaster.DoEvent(_Default_OnDoEvent);
        }

        void _Default_OnDoEvent()
        {
            Test.Text = "Clicked";
        }

希望对您有所帮助:)

Hope it will help :)