cscの作法 その484

概要

cscの作法、調べてみた。
練習問題やってみた。

練習問題

comboboxの、ValueMemberを検索して、SelectedIndexを設定せよ。

写真

サンプルコード

using System;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;
using System.Data;

namespace App
{
	public partial class Form1: Form {
		ComboBox comboBox1;
		Button button1;
		DataTable dt;
		public Form1() {
			Text = "ComboBox";
			ClientSize = new Size(200, 200);
			Label label = new Label();
			label.Location = new Point(10, 50);
			label.Text = "フルーツ";
			Controls.Add(label);
			dt = new DataTable();
			dt.Columns.AddRange(new DataColumn[] {
				new DataColumn("id", typeof(int)),
				new DataColumn("name", typeof(string))
			});
			dt.Rows.Add(0, "");
			dt.Rows.Add(1, "バナナ");
			dt.Rows.Add(2, "マンゴー");
			dt.Rows.Add(3, "パパイア");
			dt.Rows.Add(4, "キウイ");
			comboBox1 = new ComboBox();
			comboBox1.Location = new Point(30, 100);
			comboBox1.DataSource = dt;
			comboBox1.DisplayMember = "name";
			comboBox1.ValueMember = "id";
			comboBox1.SelectedIndex = -1;
			comboBox1.SelectedValueChanged += comboBox1_TextChanged;
			Controls.Add(comboBox1);
			button1 = new Button();
			button1.Text = "set";
			button1.AutoSize = true;
			button1.Dock = DockStyle.Bottom;
			button1.BackColor = Color.Aqua;
			button1.Click += new EventHandler(button1_Click);
			this.Controls.Add(button1);
		}
		private void comboBox1_TextChanged(object sender, EventArgs e) {
			int n = comboBox1.SelectedIndex;
			string str = comboBox1.Text;
			string str1 = comboBox1.SelectedValue.ToString();
			MessageBox.Show("selected: " + n + " (" + str + ": " + str1 + ")");
		}
		private void button1_Click(object sender, EventArgs e) {
			for (int i = 0; i < dt.Rows.Count; i++)
			{
				DataRow row = dt.Rows[i];
				if (Convert.ToInt32(row["id"]) == 2)
					comboBox1.SelectedIndex = i;
			}
		}
		[STAThread]
		public static void Main() {
			Application.Run(new Form1());
		}
	}
}

以上。