Introduction
MessageBox is a class in C#, and Show is a method that displays a message in a small window in the center of the Form.
MessageBox is used to provide confirmations of a task being done or to provide warnings before a task is done.
Create a Windows Forms app in Visual Studio and add a button on it. Something like this is below.
Example
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Figure 1. Windows Form
Let's say you want to show a message on a button click event handler. Here is the code for that.
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Figure 2. Code Snippet
OUTPUT
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Figure 3. Showing the output
Note. By default, the OK Button will be shown.
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Figure 4. Second and third argument MessageBoxIcon
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Figure 5. The fourth argument specifies MessageBoxIcon
What is DialogResult?
DialogResult is an enumeration of the possible return values of a dialog box, including a MessageBox. The Show method returns a DialogResult that tells us what button a user has clicked on in the message box.
publicstaticSystem.Windows.Forms.DialogResultShow(stringtext);
Here are the values of DialogResult.
- Abort: The dialog box return value is Abort (usually sent from a button labeled Abort).
- Cancel: The dialog box return value is Cancel (usually sent from a button labeled Cancel).
- Ignore: The dialog box return value is Ignore (usually sent from a button labeled Ignore).
- No: The dialog box return value is No (usually sent from a button labeled No).
- None: Nothing is returned from the dialog box. This means that the modal dialog continues running.
- OK: The dialog box return value is OK (usually sent from a button labeled OK).
- Retry: The dialog box return value is Retry (usually sent from a button labeled Retry).
- Yes: The dialog box return value is Yes (usually sent from a button labeled Yes).
For example, if you want to ask a user to close a form on a Yes button click of a message box, you can do something like this.
Form1.cs code
private void button1_Click(object sender, EventArgs e)
{
DialogResult result;
result = MessageBox.Show("Welcome to C# Corner", "Learn C#", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
if (result == DialogResult.Yes)
{
Close();
}
}
OUTPUT
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Figure 7. Final output
Thank you.
Learn more about C# MessageBox, here is a detailed article: Message Box in C#