hi:

 When the TextBox the focus changes, how to switch the display Text?

The following is my code, how do I do?

When the focus changes textBox1, and not re-call GetText.

CustomTextBox.cs

using System;
using System.Data;
using Gizmox.WebGUI.Forms;

namespace TestWebGuiTextBoxFocus
{
    public class CustomTextBox : TextBox
    {
        public override string Text
        {
            get
            {
                return base.Text;
            }
            set
            {
                if (base.Focused)
                    string.Format("Test [{0}] ", base.Text);
                else
                    base.Text = value;
            }
        }
    }
}

Form1.cs

#region Using

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;

using Gizmox.WebGUI.Common;
using Gizmox.WebGUI.Forms;

#endregion

namespace TestWebGuiTextBoxFocus
{
    public partial class Form1 : Form
    {

        private CustomTextBox textBox1;
        private Gizmox.WebGUI.Forms.TextBox textBox2;

        public Form1()
        {
            InitializeComponent();
        }

        private void textBox1_GotFocus(object sender, EventArgs e)
        {
            base.Update();
        }

        private void textBox1_LostFocus(object sender, EventArgs e)
        {
            base.Update();
        }

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.textBox1 = new TestWebGuiTextBoxFocus.CustomTextBox();
            this.textBox2 = new Gizmox.WebGUI.Forms.TextBox();
            this.SuspendLayout();
            //
            // textBox1
            //
            this.textBox1.Location = new System.Drawing.Point(63, 47);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(100, 21);
            this.textBox1.TabIndex = 0;
            this.textBox1.Text = "Value";
            this.textBox1.LostFocus += new System.EventHandler(this.textBox1_LostFocus);
            this.textBox1.GotFocus += new System.EventHandler(this.textBox1_GotFocus);
            //
            // textBox2
            //
            this.textBox2.Location = new System.Drawing.Point(63, 88);
            this.textBox2.Name = "textBox2";
            this.textBox2.Size = new System.Drawing.Size(100, 21);
            this.textBox2.TabIndex = 1;
            //
            // Form1
            //
            this.Controls.Add(this.textBox2);
            this.Controls.Add(this.textBox1);
            this.Size = new System.Drawing.Size(600, 301);
            this.Text = "Form1";
            this.ResumeLayout(false);

        }
    }
}

Hi Palli, Thanks for your answer.

I want to achieve the following functions:
1.TextBox bound to the DataTable.
2. Field decimal dalue is 100.000000 for example, when the TextBox gets the focus, the show "100.000000"; loses focus display "100", that is, dynamic format.
3. I do not know what method is the focus of changes in the TextBox to re-trigger TextBox.GetText ()?

Hi Palli:

1.Ryan 's idea I did not understand how to use CurrencyFormatter class.
2. To correct my First Code

    public class CustomTextBox : TextBox
    {

        public CustomTextBox()
        {
            this.GotFocus += DummyEventHandler;
            this.LostFocus += DummyEventHandler;
        }

        private void DummyEventHandler(object sender, EventArgs e)
        {
        }

        public override string Text
        {
            get
            {
                //old code if (base.Focused)   //Control.Focused property always returns a True result
                if (Form.ActiveControl == this)
                    return string.Format("Test [{0}] ", base.Text);
                else
                    return base.Text;
            }
            set
            {
                base.Text = value;
            }
        }

        protected override void OnGotFocus(EventArgs e)
        {

            //if (!(this.Tag == null))
            //{
            //    base.Text = (string)base.Tag;
            //}
            base.OnGotFocus(e);
            Update();
        }
        protected override void OnLostFocus(EventArgs e)
        {
            //base.Tag = base.Text;
            //base.Text = string.Format("Test [{0}] ", base.Text);
            base.OnLostFocus(e);
            Update();
        }

    }
3. Subsequently, after the test is Control.Focused property always returns a True result.

4.Generated after the code above into another problem: should have been the focus of control, when the implementation of the Update () method after, CustomTextBox lost focus.