C＃：按下Enter键时更改DropDownList值(C#: Change DropDownList value when Enter key is pressed)

C＃：按下Enter键时更改DropDownList值(C#: Change DropDownList value when Enter key is pressed)

我有一个带有DropDownList的Windows窗体，其中包含固定数量的项目。 当我按Enter键时，如何使DropDownList增量到下一个项目，当它到达项目的末尾时，返回到第一个项目。

I have a windows form with a DropDownList with a fixed number of items. How do I make the DropDownList increment to the next item when I press Enter and when it reaches the end of the items, return to the first item.

最满意答案

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; namespace WindowsFormsApplication1 { public partial class Form1 : Form { public Form1() { InitializeComponent(); this.KeyPreview = true; } private void Form1_Load(object sender, EventArgs e) { this.comboBox1.DataSource = CreateItems(); } private List<string> CreateItems() { List<string> lst = new List<string>(); lst.Add("One"); lst.Add("Two"); lst.Add("Three"); lst.Add("Four"); return lst; } private void comboBox1_KeyDown(object sender, KeyEventArgs e) { if (e.KeyData == Keys.Enter) { if (comboBox1.SelectedIndex == comboBox1.Items.Count-1) { comboBox1.SelectedIndex = 0; return; } if (comboBox1.SelectedIndex >=0 & comboBox1.SelectedIndex< comboBox1.Items.Count-1) { comboBox1.SelectedIndex = comboBox1.SelectedIndex+1; } } } } } using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; namespace WindowsFormsApplication1 { public partial class Form1 : Form { public Form1() { InitializeComponent(); this.KeyPreview = true; } private void Form1_Load(object sender, EventArgs e) { this.comboBox1.DataSource = CreateItems(); } private List<string> CreateItems() { List<string> lst = new List<string>(); lst.Add("One"); lst.Add("Two"); lst.Add("Three"); lst.Add("Four"); return lst; } private void comboBox1_KeyDown(object sender, KeyEventArgs e) { if (e.KeyData == Keys.Enter) { if (comboBox1.SelectedIndex == comboBox1.Items.Count-1) { comboBox1.SelectedIndex = 0; return; } if (comboBox1.SelectedIndex >=0 & comboBox1.SelectedIndex< comboBox1.Items.Count-1) { comboBox1.SelectedIndex = comboBox1.SelectedIndex+1; } } } } }