页面page_A里使用了用户控件uc_A,用户控件uc_A中嵌套了用户控件uc_B,当触发了用户控件uc_B中的事件后需要调用uc_A中的方法以更新uc_A的内容.我尝试在uc_B中使用这样的方法来达到目的:protected void uc_B_Event(param param1)
{
... ...
Page p = this.Parent.Page;
UserControl uc = p.FindControl(uc_A) as UserControl;
Type t = uc.GetType();
MethodInfo mi = t.GetMethod(uc_A_Function);
if (mi != null)
{
mi.Invoke(uc, new object[] {});
}
} 错误提示:"System.NullReferenceException: 未将对象引用设置到对象的实例"
错误提示行:Type t = uc.GetType();如何在嵌套用户控件中互相调用其方法呢?
{
... ...
Page p = this.Parent.Page;
UserControl uc = p.FindControl(uc_A) as UserControl;
Type t = uc.GetType();
MethodInfo mi = t.GetMethod(uc_A_Function);
if (mi != null)
{
mi.Invoke(uc, new object[] {});
}
} 错误提示:"System.NullReferenceException: 未将对象引用设置到对象的实例"
错误提示行:Type t = uc.GetType();如何在嵌套用户控件中互相调用其方法呢?
UserControl1:<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="WebUserControl1.ascx.cs" Inherits="WebApplication1.WebUserControl1" %>
<%@ Register Src="~/WebUserControl2.ascx" TagPrefix="my" TagName="uc2" %><my:uc2 runat="server" ID="UC2" />
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
public partial class WebUserControl1 : System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{ } public void SetText(string str)
{
this.TextBox1.Text = str;
}
}
UserControl2:<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="WebUserControl2.ascx.cs" Inherits="WebApplication1.WebUserControl2" %>
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" /> public partial class WebUserControl2 : System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{ } protected void Button1_Click(object sender, EventArgs e)
{
if (this.Parent is UserControl)
{
System.Reflection.MethodInfo mi = this.Parent.GetType().GetMethod("SetText", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public);
if (mi != null)
{
mi.Invoke(this.Parent, new object[] { "Hello" });
}
}
}
}
调用页:<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="flash.aspx.cs" Inherits="WebApplication1.flash" %>
<%@ Register Src="~/WebUserControl1.ascx" TagPrefix="my" TagName="uc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<my:uc1 ID="UC1" runat="server"></my:uc1>
</div>
</form>
</body>
</html>
{
if (this.Parent is WebUserControl1)
{
WebUserControl1 wuc = this.Parent as WebUserControl1;
wuc.SetText("Hello");
}
}