ایجاد textbox مانند یک dropdownlist

لطفا کمک کنید

چطور میشه توی #c یک textbox مانند نمونه ضمیمه ایجاد کرد؟؟
هر چی گشتم هیچی پیدا نکردم

اسم این قابلیت چیه؟؟!!

ATTACH=CONFIG]75764[/ATTACH]]

یعنی هیچ کس بلد نیست ؟؟؟؟
حتی اسمشم نمیدونید؟؟:گریه:

salam
khodam peydash kardam

code for main form:

using System;

using System.Collections.Generic;

using System.Drawing;

using System.Windows.Forms;

 

namespace Test_app

{

    /// <summary>

    /// Description of MainForm.

    /// </summary>

    public partial class MainForm : Form

    {

        public MainForm()

        {

            //

            // The InitializeComponent() call is required for 

            //  Windows Forms designer support.

            //

            InitializeComponent();

 

            //

            // TODO: Initially Set Height to only one line ,

            //        watch out for font size in text box it is set to 8

            //         Width is 300

            //

            textBox1.Multiline = false;

            textBox1.Width = 300;

            textBox1.Height = 20;

            textBox1.Refresh();

        }

 

        void TextBox1MouseClick(object sender, MouseEventArgs e)

        {

            // TODO: Implement TextBox1MouseClick

            // When you click with mouse on text box it opens

            // by changing its Height

            textBox1.Multiline = true;

            textBox1.BringToFront();

            textBox1.Width = 300;

            textBox1.Height = 200;

            textBox1.Refresh();

        }

 

        void TextBox1MouseDoubleClick(object sender, MouseEventArgs e)

        {

            // TODO: Implement TextBox1MouseDoubleClick

            // When you double click with mouse on text box it closes

            // by changing its Height

            textBox1.Multiline = false;

            textBox1.Multiline = true;

            textBox1.Width = 300;

            textBox1.Height = 20;

            textBox1.Refresh();

        }

    }

}

code for Program.cs:

using System;

using System.Windows.Forms;

 

namespace Test_app

{

    /// <summary>

    /// Class with program entry point.

    /// </summary>

    internal sealed class Program

    {

        /// <summary>

        /// Program entry point.

        /// </summary>

        [STAThread]

        private static void Main(string[] args)

        {

            Application.EnableVisualStyles();

            Application.SetCompatibleTextRenderingDefault(fals  e);

            Application.Run(new MainForm());

        }

 

    }

}

and code for MainForm.Designer.cs

namespace Test_app

{

    partial class MainForm

    {

        /// <summary>

        /// Designer variable used to keep track of non-visual components.

        /// </summary>

        private System.ComponentModel.IContainer components = null;

 

        /// <summary>

        /// Disposes resources used by the form.

        /// </summary>

        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>

        protected override void Dispose(bool disposing)

        {

            if (disposing) {

                if (components != null) {

                    components.Dispose();

                }

            }

            base.Dispose(disposing);

        }

 

        /// <summary>

        /// This method is required for Windows Forms designer support.

        /// Do not change the method contents inside the source code editor. The Forms designer might

        /// not be able to load this method if it was changed manually.

        /// </summary>

        private void InitializeComponent()

        {

            this.textBox1 = new System.Windows.Forms.TextBox();

            this.SuspendLayout();

            //

            // textBox1

            //

            this.textBox1.Location = new System.Drawing.Point(3, 12);

            this.textBox1.Multiline = true;

            this.textBox1.Name = "textBox1";

            this.textBox1.Size = new System.Drawing.Size(300, 200);

            this.textBox1.TabIndex = 2;

            this.textBox1.MouseDoubleClick += new System.Windows.Forms.MouseEventHandler(this.TextBo  x1MouseDoubleClick);

            this.textBox1.MouseClick += new System.Windows.Forms.MouseEventHandler(this.TextBo  x1MouseClick);

            //

            // MainForm

            //

            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);

            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;

            this.ClientSize = new System.Drawing.Size(348, 244);

            this.Controls.Add(this.textBox1);

            this.Name = "MainForm";

            this.Text = "Test app";

            this.ResumeLayout(false);

            this.PerformLayout();

        }

        public System.Windows.Forms.TextBox textBox1;

 

    }

}

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