想在ASP.NET页面实现：页面打开后台添加按钮A，点击A，自动添加按钮B，点击B自动添加按钮C。

因为点击B按钮后会回传，Page_Load又执行一次，btn2当然不见了，如果你确实要用御冲竖这种方法实现这功能的话，可以在页面加一个HiddenField，然判返后按下镇大面这样写：

protected void Page_Load(object sender, EventArgs e)

{

Button btn = new Button()

btn.ID = "A"

btn.Text = "A"

btn.Click += new System.EventHandler(btn_click)

this.form1.Controls.Add(btn)

if (HiddenField1.Value=="1")

{

Button btn2 = new Button()

btn2.ID = "B"

btn2.Text = "B"

btn2.Click += new System.EventHandler(btn2_click)

this.form1.Controls.Add(btn2)

}

}

private void btn_click(object sender, System.EventArgs e)

{

Button b1 = (Button)sender

Button btn2 = new Button()

btn2.ID = "B"

btn2.Text = "B"

btn2.Click += new System.EventHandler(btn2_click)

this.form1.Controls.Add(btn2)

HiddenField1.Value = "1"// 主要用来标记已经添加了按钮B

}

private void btn2_click(object sender, System.EventArgs e)

{

Button b2 = (Button)sender

Button btn3 = new Button()

btn3.ID = "C"

btn3.Text = "C"

this.form1.Controls.Add(btn3)

}

<script>

function up(){

<%

for i=1 to 100

a=a+i

next

%>兄则皮

alert("盯闹<%=a%>")

}

</script>

<input type="羡差button" id="123" name="up" value="按钮" onclick="up()"/>

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