How to check control Type in Switch Case

Question

How to check control types in switch case statement?

Private void CheckControl(Control ctl) 
{
    switch (ctl) {
        case TextBox: MessageBox.Show("This is My TextBox");
        break;

        case Label: MessageBox.Show("This is My Label");
        break;
    }
}  

Following is error in above statement:

'Textbox' is a type, which is not valid in the given context

Answer 1

As of C# 7 you can use type patterns for this:

private void CheckControl(Control ctl)
{
    switch (ctl)
    {
        case TextBox _: 
            MessageBox.Show("This is My TextBox");
            break;
        case Label _: 
            MessageBox.Show("This is My Label");
            break;
    }
}

Here _ is the syntax for a discard, meaning you don't need to access the value as a TextBox (or Label) afterwards.

If you do want to access members of the specific type, you can introduce a pattern variable:

private void CheckControl(Control ctl)
{
    switch (ctl)
    {
        case TextBox textBox: 
            // Use textBox for any TextBox-specific members here
            MessageBox.Show("This is My TextBox");
            break;
        case Label label: 
            // Use label for any Label-specific members here
            MessageBox.Show("This is My Label");
            break;
    }
}

Answer 2

try:

switch (ctl?.GetType().Name) {
    case "TextBox": MessageBox.Show("This is My TextBox");
    break;

    case "Label": MessageBox.Show("This is My Label");
    break;
}