1，自定义事件：
public class TextChangeEventArgs : EventArgs
{
private string message;
public TextChangeEventArgs(string message)
{
this.message = message;
}
public string Message
{
get{return message;}
}
}
2，定义委托为，
public delegate void TextBoxChangedHandle(object sender,TextChangeEventArgs e);
接下去在用户控件中添加事件，
//定义事件
public event TextBoxChangedHandle UserControlValueChanged;
为了激发用户控件的新增事件，修改了一下代码，
private void textBox1_TextChanged(object sender, System.EventArgs e)
{
if(UserControlValueChanged != null)
UserControlValueChanged(this,new TextChangeEventArgs(this.textBox1.Text));
}
3，调用事件
this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
private void textBox1_TextChanged(object sender, System.EventArgs e)
{
if(UserControlValueChanged != null)
UserControlValueChanged(this,new TextChangeEventArgs(this.textBox1.Text));
}