Mavzu: Windows uchun dasturlashda ComboBox komponenti va uning turli xossalari bilan ishlash. Reja: ComboBox element

Misollar

Quyidagi kod misoli, siz qanday foydalanish mumkinligini ko'rsatuvchi to'liq dasturi Add a uchun ma'lumotlar kiritish uchun usul ComboBox , FindString bir yilda mahsulot topish usuli ComboBox va BeginUpdate va EndUpdate bir katta raqam terilgan samarali usullari qo'shish ComboBox . Ko'rsatilgan matndan farq qiladigan qiymatlarni saqlash qobiliyati ListControl- dan meros bo'lib o'tgan . Ushbu xususiyatdan qanday foydalanish haqida misol uchun ListControl sinfiga qarang .
Ushbu misolni bajarish uchun siz System.Drawingva System.Windows.Formsism maydonlariga havolalar qo'shishingiz kerak .
C # Nusxalash
using System;
using System.Windows.Forms;

namespace Win32Form1Namespace {

public class Win32Form1 : System.Windows.Forms.Form {

private System.Windows.Forms.Button addButton;
private System.Windows.Forms.TextBox textBox2;
private System.Windows.Forms.Button addGrandButton;
private System.Windows.Forms.ComboBox comboBox1;
private System.Windows.Forms.Button showSelectedButton;
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.Button findButton;
private System.Windows.Forms.Label label1;
public Win32Form1() {
this.InitializeComponent();
}
[System.STAThreadAttribute()]
public static void Main() {
System.Windows.Forms.Application.Run(new Win32Form1());
}
private void InitializeComponent() {
this.addButton = new System.Windows.Forms.Button();
this.textBox2 = new System.Windows.Forms.TextBox();
this.addGrandButton = new System.Windows.Forms.Button();
this.comboBox1 = new System.Windows.Forms.ComboBox();
this.showSelectedButton = new System.Windows.Forms.Button();
this.textBox1 = new System.Windows.Forms.TextBox();
this.findButton = new System.Windows.Forms.Button();
this.label1 = new System.Windows.Forms.Label();
this.addButton.Location = new System.Drawing.Point(248, 32);
this.addButton.Size = new System.Drawing.Size(40, 24);
this.addButton.TabIndex = 1;
this.addButton.Text = "Add";
this.addButton.Click += new System.EventHandler(this.addButton_Click);
this.textBox2.Location = new System.Drawing.Point(8, 64);
this.textBox2.Size = new System.Drawing.Size(232, 20);
this.textBox2.TabIndex = 6;
this.textBox2.Text = "";
this.addGrandButton.Location = new System.Drawing.Point(8, 96);
this.addGrandButton.Size = new System.Drawing.Size(280, 23);
this.addGrandButton.TabIndex = 2;
this.addGrandButton.Text = "Add 1,000 Items";
this.addGrandButton.Click += new System.EventHandler(this.addGrandButton_Click);
this.comboBox1.Anchor = ((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.comboBox1.DropDownWidth = 280;
this.comboBox1.Items.AddRange(new object[] {"Item 1",
"Item 2",
"Item 3",
"Item 4",
"Item 5"});
this.comboBox1.Location = new System.Drawing.Point(8, 248);
this.comboBox1.Size = new System.Drawing.Size(280, 21);
this.comboBox1.TabIndex = 7;
this.showSelectedButton.Location = new System.Drawing.Point(8, 128);
this.showSelectedButton.Size = new System.Drawing.Size(280, 24);
this.showSelectedButton.TabIndex = 4;
this.showSelectedButton.Text = "What Item is Selected?";
this.showSelectedButton.Click += new System.EventHandler(this.showSelectedButton_Click);
this.textBox1.Location = new System.Drawing.Point(8, 32);
this.textBox1.Size = new System.Drawing.Size(232, 20);
this.textBox1.TabIndex = 5;
this.textBox1.Text = "";
this.findButton.Location = new System.Drawing.Point(248, 64);
this.findButton.Size = new System.Drawing.Size(40, 24);
this.findButton.TabIndex = 3;
this.findButton.Text = "Find";
this.findButton.Click += new System.EventHandler(this.findButton_Click);
this.label1.Location = new System.Drawing.Point(8, 224);
this.label1.Size = new System.Drawing.Size(144, 23);
this.label1.TabIndex = 0;
this.label1.Text = "Test ComboBox";
this.ClientSize = new System.Drawing.Size(292, 273);
this.Controls.AddRange(new System.Windows.Forms.Control[] {this.comboBox1,
this.textBox2,
this.textBox1,
this.showSelectedButton,
this.findButton,
this.addGrandButton,
this.addButton,
this.label1});
this.Text = "ComboBox Sample";
}
private void addButton_Click(object sender, System.EventArgs e) {
comboBox1.Items.Add(textBox1.Text);
}

private void addGrandButton_Click(object sender, System.EventArgs e) {

comboBox1.BeginUpdate();
for (int i = 0; i < 1000; i++) {
comboBox1.Items.Add("Item 1" + i.ToString());
}
comboBox1.EndUpdate();
}

private void findButton_Click(object sender, System.EventArgs e) {

int index = comboBox1.FindString(textBox2.Text);
comboBox1.SelectedIndex = index;
}

private void showSelectedButton_Click(object sender, System.EventArgs e) {

int selectedIndex = comboBox1.SelectedIndex;
Object selectedItem = comboBox1.SelectedItem;

MessageBox.Show("Selected Item Text: " + selectedItem.ToString() + "\n" +

"Index: " + selectedIndex.ToString());
}
}
}