How to disable a checkbox if another checkbox is enabled?

Question

My web-page have two check-boxes and What I want is:

Initially both check-boxes are unchecked.
if Checkbox1 is checked, Checkbox2 should becomes disabled.
if Checkbox2 is unchecked again, Checkbox2 should becomes enabled again.
and vice versa.

Please help me in modifying my code.

Here is my code:

protected void CheckBox1_CheckedChanged1(object sender, EventArgs e)
{
   //this.CheckBox1.CheckedChanged += new System.EventHandler(CheckBox1_CheckedChanged1);
    if (CheckBox1.Checked)
        CheckBox2.Enabled = false;
}

protected void CheckBox2_CheckedChanged2(object sender, EventArgs e)
{
    if (CheckBox2.Checked)
        CheckBox1.Enabled = false;
}

HTML

<asp:CheckBox ID="CheckBox1" runat="server" Height="33px" OnCheckedChanged="CheckBox1_CheckedChanged1" Font-Bold="True" style="margin-left: 33px" Text="Remove Blank Lines" TextAlign="Left" Width="162px" />


<asp:CheckBox ID="CheckBox2" runat="server" Font-Bold="True" Height="33px" OnCheckedChanged="CheckBox2_CheckedChanged2" style="margin-left: 28px" Text="Add Prefix/ Suffix to Blank Lines" TextAlign="Left" Width="259px" />

Why dont just use a radio button ? – Haroon nasir Mar 22 '19 at 06:14 — Haroon nasir, Mar 22 '19 at 06:14

score 0 · Answer 1 · answered Mar 22 '19 at 06:14

0

Just use:

CheckBox2.Enabled = !CheckBox1.Checked;

answered Mar 22 '19 at 06:14

Michał Turczyn

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@Emmy, I think you have to write above condition for `CheckBox1` also like => `CheckBox1.Enabled = !CheckBox2.Checked;` in `CheckBox2_CheckedChanged2` event handler. – er-sho Mar 22 '19 at 06:32
3

Probably @Emmy assumes this is client-side code while it is actually server-side code that either requires `AutoPostBack="true"` or a submit button. Maybe provide a client-side-only solution, too? – Uwe Keim Mar 22 '19 at 06:34

score 0 · Answer 2 · answered Mar 22 '19 at 07:57

This answer for clarification to the new contributor

Add The AutoPostBack property to each checkbox control

<asp:CheckBox ID="CheckBox1" runat="server" AutoPostBack ="True" OnCheckedChanged="CheckBox_CheckedChanged" Height="33px"  Font-Bold="True" style="margin-left: 33px"  Text="Remove Blank Lines" TextAlign="Left" Width="162px" />


<asp:CheckBox ID="CheckBox2" runat="server" AutoPostBack ="True" OnCheckedChanged="CheckBox_CheckedChanged" Font-Bold="True" Height="33px"  style="margin-left: 28px"   Text="Add Prefix/ Suffix to Blank Lines" TextAlign="Left" Width="259px" />

then in code-behind

create one event CheckBox_CheckedChanged and point each checkbox at it:

protected void CheckBox_CheckedChanged(object sender, EventArgs e)
  {
     CheckBox1.Enabled = !CheckBox2.Checked;
     CheckBox2.Enabled = !CheckBox1.Checked;
  }

How to disable a checkbox if another checkbox is enabled?

2 Answers2