[英]Simple display with OnChange event on textbox
如何在Textbox1和Textbox2中輸入值后立即使用OnChange事件在Label1上顯示結果?
<div>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
---------------------------------------------------------------------------------------
//Code behind
int num1;
if(!Int32.TryParse(TextBox1.Text, out num1))
{
Label1.Text = "Not a valid number";
return;
}
int num2;
if(!Int32.TryParse(TextBox2.Text, out num2))
{
Label1.Text = "Not a valid number";
return;
}
sum = num1 + num2;
Label1.Text = sum.ToString();
要使用TextChangedEvent
您需要在代碼中添加TextChangedEvent
事件處理程序,並在標記中設置AutoPostBack=true
<asp:TextBox ID="TextBox2" runat="server" OnTextChanged="TextBox2_TextChanged" AutoPostBack="true"></asp:TextBox>
代碼背后
protected void TextBox2_TextChanged(object sender,EventArgs e)
{
int num1;
if(!Int32.TryParse(TextBox1.Text, out num1))
{
Label1.Text = "Not a valid number";
return;
}
int num2;
if(!Int32.TryParse(TextBox2.Text, out num2))
{
Label1.Text = "Not a valid number";
return;
}
sum = num1 + num2;
Label1.Text = sum.ToString();
}
這適用於兩個文本框: -
<div>
<asp:TextBox ID="TextBox1" OnTextChanged="AnyTextBox_TextChanged" AutoPostBack="true" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox2" OnTextChanged="AnyTextBox_TextChanged" AutoPostBack="true" runat="server"></asp:TextBox>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
代碼背后:
protected void AnyTextBox_TextChanged(object sender, EventArgs e)
{
int sum = 0;
int num1;
if (!Int32.TryParse(TextBox1.Text, out num1))
{
Label1.Text = "Not a valid number";
return;
}
int num2;
if (!Int32.TryParse(TextBox2.Text, out num2))
{
Label1.Text = "Not a valid number";
return;
}
sum = num1 + num2;
Label1.Text = sum.ToString();
}
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