高手来看~~动态生成的控件如何加载事件？

[wdf618]

想做一个简单的功能
点击Button1动态生成一个Button2（Button2是不存在的，是动态生成的，回传后会消失）,点击Button2能运行服务器端的一段代码，要求：Button2的onclick事件代码不写在js中，回传后button2还在。

代码：

public partial class Default3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        Button L_Button = new Button();
        L_Button.ID = "Button2";
        L_Button.Text = "输出";
        L_Button.Attributes.Add("runat", "server");
        L_Button.BackColor = System.Drawing.Color.Blue;
        L_Button.ForeColor = System.Drawing.Color.Wheat;
        L_Button.Click += new EventHandler(this.CCC);//这句话我试着写的，发觉无效       
        Panel1.Controls.Add(L_Button);

    }
    protected void CCC(object sender, EventArgs e)
    {
        Response.Write("XXX");
    }
}

我是希望点击button2能够运行CCC方法，该怎么写？
这个我可以利用ajax做
写个

L_Button.Attributes.Add("OnClick","Button2_Click")；

然后在前台写一个

function Button2_Click()
{
 //调用ajax引擎，执行CCC函数
 ...
}

但是我现在想要不借助js和ajax不知该如何实现~~
请各位高手支招！

[girlhappy]

你可以把这几句
L_Button.Attributes.Add("runat", "server");
L_Button.BackColor = System.Drawing.Color.Blue;
L_Button.ForeColor = System.Drawing.Color.Wheat;
L_Button.Click += new EventHandler(this.CCC);//这句话我试着写的，发觉无效
换成
L_Button.BackColor = System.Drawing.Color.Blue;
L_Button.ForeColor = System.Drawing.Color.Wheat;
L_Button.Click += new EventHandler(L_Button_Click );


protected void L_Button_Click (object sender, EventArgs e)
{
Response.Write("XXX");
}

[wdf618]

经鉴定，一楼的无效！
期待更多有效的回答~~~

[wdf618]

这里使用ViewState比Session更好~~受教了！
下面是我经过测试了的代码：

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            //Session["Button_2_Exist"] = false;//用来指示其他控件的回传是否创建该按钮
            ViewState["Button_2_Exist"] = false;
        }
        if (IsPostBack)
        {
            if (Request.Form["Button1"] == null)//用来指示button1引发的回传是否创建该按钮
            {
                if ((bool)ViewState["Button_2_Exist"])
                {
                    Panel1.Controls.Add(Build_Button());
                }
            }
        }
    }

 protected void Button1_Click(object sender, EventArgs e)
    {
        if (!(bool)ViewState["Button_2_Exist"])
        {
            Panel1.Controls.Add(Build_Button());
            ViewState["Button_2_Exist"] = true;
        }
        else
        {
            ViewState["Button_2_Exist"] = false;
        }
    }

protected Button Build_Button()
    {
        Button L_Button = new Button();
        L_Button.ID = "Button_2";
        L_Button.Text = "输出";
        L_Button.Attributes.Add("runat", "server");
        L_Button.BackColor = System.Drawing.Color.Blue;
        L_Button.ForeColor = System.Drawing.Color.Wheat;
        //Response.Write("<SCRIPT> function DDD() {alert('XXXX');} </SCRIPT>");
        //L_Button.Attributes.Add("OnClick", "DDD()");
        L_Button.Click += new EventHandler(L_Button_Click);
        return (L_Button);
    }

 protected void L_Button_Click(object sender, EventArgs e)
    {
        Response.Write("XXX");
    } 

[wdf618]

这里使用ViewState比Session更好~~受教了！
下面是我经过测试了的代码：

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            //Session["Button_2_Exist"] = false;//用来指示其他控件的回传是否创建该按钮
            ViewState["Button_2_Exist"] = false;
        }
        if (IsPostBack)
        {
            if (Request.Form["Button1"] == null)//用来指示button1引发的回传是否创建该按钮
            {
                if ((bool)ViewState["Button_2_Exist"])
                {
                    Panel1.Controls.Add(Build_Button());
                }
            }
        }
    }

 protected void Button1_Click(object sender, EventArgs e)
    {
        if (!(bool)ViewState["Button_2_Exist"])
        {
            Panel1.Controls.Add(Build_Button());
            ViewState["Button_2_Exist"] = true;
        }
        else
        {
            ViewState["Button_2_Exist"] = false;
        }
    }

protected Button Build_Button()
    {
        Button L_Button = new Button();
        L_Button.ID = "Button_2";
        L_Button.Text = "输出";
        L_Button.Attributes.Add("runat", "server");
        L_Button.BackColor = System.Drawing.Color.Blue;
        L_Button.ForeColor = System.Drawing.Color.Wheat;
        //Response.Write("<SCRIPT> function DDD() {alert('XXXX');} </SCRIPT>");
        //L_Button.Attributes.Add("OnClick", "DDD()");
        L_Button.Click += new EventHandler(L_Button_Click);
        return (L_Button);
    }

 protected void L_Button_Click(object sender, EventArgs e)
    {
        Response.Write("XXX");
    } 

[cong1212]

以前我也做过,这样做就是反复加载Button,其实这里你可以在动态生成Button时后就把button保持到Session里,再在Load里取出加载事件,这样就可以不用反复加载了.跟你上面的比各有优越性

[wdf618]

没人知道么？！！！

[皮皮鲁是]

学习了 帮你顶

[lovehongyun]

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class Default9 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            Button L_Button = new Button();
            L_Button.ID = "Button2";
            L_Button.Text = "输出";
            L_Button.Attributes.Add("runat", "server");
            L_Button.BackColor = System.Drawing.Color.Blue;
            L_Button.ForeColor = System.Drawing.Color.Wheat;
            L_Button.Click += new EventHandler(L_Button_Click);
            this.form1.Controls.Add(L_Button);
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
       
    }

    void L_Button_Click(object sender, EventArgs e)
    {
        Response.Write("dd");
    }
}

[lovehongyun]

如果你要动态生成控件,就要保证每次加载都要执行生成控件的动作,否则会刷没的.

[ReyZhang]

顶ls ,因为是动态创建控件,并给控件注册事件,要保证页面每次刷新时都能加载到此控件的创建

放到 if (IsPostBack) 中去执行

[wdf618]

感谢 lovehongyun ，现在我把代码改成了这样

protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            
            Panel1.Controls.Add(Build_Button());
            
        }
    }

 protected void Button1_Click(object sender, EventArgs e)
    {        
        Panel1.Controls.Add(Build_Button());
    }

protected Button Build_Button()
    {
        Button L_Button = new Button();
        L_Button.ID = "Button_2";
        L_Button.Text = "输出";
        L_Button.Attributes.Add("runat", "server");
        L_Button.BackColor = System.Drawing.Color.Blue;
        L_Button.ForeColor = System.Drawing.Color.Wheat;
        //Response.Write("<SCRIPT> function DDD() {alert('XXXX');} </SCRIPT>");
        //L_Button.Attributes.Add("OnClick", "DDD()");
        L_Button.Click += new EventHandler(L_Button_Click);
        return (L_Button);
    }

protected void L_Button_Click(object sender, EventArgs e)
    {
        Response.Write("XXX");
    } 

现在的问题是我希望点击了Button1之后才出现这个动态加载的[输出]按钮，但是如我上面这样写任何回传都会加载这个按钮，并且点击Button1时会出现两个[输出]按钮
我想到的解决方法是在

protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            if([输出]按钮不存在)
            {
                Panel1.Controls.Add(Build_Button());
            }
            
        }
    }

现在的问题是怎么判断该按钮不存在呢？我试着用request.form[]，但是按钮不被包含在表单内提交，除非是它自身被点击的时候。
一个解决办法是可以用session存一个变量来指示，但是有没有别的办法可以直接获取浏览器端该按钮的状态呢（比方说能让form每次都提交该按钮的text，如果取不到说明该按钮不存在）?

[lovehongyun]

我没测,你自己试试.

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class Default9 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            if (ViewState["flag"] != null)
            {
                this.form1.Controls.Add(Build_Button());    
            }
                        
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        if (ViewState["flag"] == null)
        {
            this.form1.Controls.Add(Build_Button());
            ViewState["flag"] = true;
        }
    }

    void L_Button_Click(object sender, EventArgs e)
    {
        Response.Write("dd");
    }

    Button Build_Button()
    {
        Button L_Button = new Button();
        L_Button.ID = "Button2";
        L_Button.Text = "输出";
        L_Button.Attributes.Add("runat", "server");
        L_Button.BackColor = System.Drawing.Color.Blue;
        L_Button.ForeColor = System.Drawing.Color.Wheat;
        L_Button.Click += new EventHandler(L_Button_Click);
        return L_Button;
    }

}