Form Focus event : Form Event : GUI Windows Form C# Source Code

    
 

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

public class FocusForm : System.Windows.Forms.Form {
    private System.Windows.Forms.TextBox txtFocusForm;
    private System.Windows.Forms.Button btFocusForm;
    public FocusForm() {
        this.txtFocusForm = new System.Windows.Forms.TextBox();
        this.btFocusForm = new System.Windows.Forms.Button();
        this.SuspendLayout();

        this.txtFocusForm.Location = new System.Drawing.Point(8, 8);
        this.txtFocusForm.Size = new System.Drawing.Size(336, 20);
        this.txtFocusForm.LostFocus += new System.EventHandler(this.txtFocusForm_LostFocus);
        this.txtFocusForm.GotFocus += new System.EventHandler(this.txtFocusForm_GotFocus);

        this.btFocusForm.Location = new System.Drawing.Point(8, 40);
        this.btFocusForm.Size = new System.Drawing.Size(336, 23);
        this.btFocusForm.Click += new System.EventHandler(this.btFocusForm_Click);

        this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
        this.ClientSize = new System.Drawing.Size(352, 70);
        this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                      this.btFocusForm,
                                      this.txtFocusForm});
        this.ResumeLayout(false);
    }

    [STAThread]
    static void Main() {
        Application.Run(new FocusForm());
    }

    protected void txtFocusForm_LostFocus(object sender, EventArgs e) {
        Console.WriteLine("Goodbye!");
    }

    protected void txtFocusForm_GotFocus(object sender, EventArgs e) {
        Console.WriteLine("Hello!");
    }

    private void btFocusForm_Click(object sender, System.EventArgs e) {
        bool canFocus = txtFocusForm.CanFocus;
        bool containsFocus = this.ContainsFocus;
        bool focused = txtFocusForm.Focused;

        Console.WriteLine("Textbox can focus: " + canFocus +
                     "\nForm children contain focus: " + containsFocus +
                     "\nTextbox has focus: " + focused);

        txtFocusForm.Focus();
    }
}