return a value from checkbox_CheckChanged

Question

How can I get a value returned from the checkbox_CheckChanged event please? Its a winforms app, and both the form and the checkbox are created programmatically. Thanks for all and any help.

Solution 1

The Controls event handlers are always "void" and you cant change the return type. Instead you can take an external variable and you change that value only in when the CheckedChanged Event occurs.

public bool checkedthecheckbox { get; set; }

CheckBox testchbox = new CheckBox();

private void Form1_Load(object sender, EventArgs e)
{
    testchbox.CheckedChanged += new EventHandler(testchbox_CheckedChanged);
}

void testchbox_CheckedChanged(object sender, EventArgs e)
{
    if (testchbox.Checked)
        checkedthecheckbox = true;
    else
        checkedthecheckbox = false;
}

Solution 2

You can get the value from 'sender' object.

CheckBox chk = (CheckBox) sender;
bool result = chk.Checked;

Solution 3

You can get the state of the Checkbox by casting the sender object from the event arguments:

public void Method1()
{
    CheckBox checkBox = new CheckBox();
    checkBox.CheckedChanged += new EventHandler(checkBox_CheckedChanged);
}

void checkBox_CheckedChanged(object sender, EventArgs e)
{
    CheckBox c = (CheckBox)sender;
    bool resutlt = c.Checked;
}

Hope this helps!

Solution 4

You can use CheckState.Checked or CheckState.Unchecked, which is built in C#. Example:

for (int i = 0; i < lsbx_layers.Items.Count; i++) {
    if (lsbx_layers.GetItemCheckState(i) == CheckState.Checked) {
        //set  boolean variable to true
    } else if (lsbx_layers.GetItemCheckState(i) == CheckState.Unchecked) {
         //set  boolean variable to false
    }
}

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Comments

[Sai Kalyan Kumar Akshinthala]

Where's your code. Can you provide that.

[user995689]

Thanks to all who answered, and specially to skk for the particular answer.