上面的代码我在测试中并不能实现,请检查代码
时间: 2024-04-21 15:24:25 浏览: 13
非常抱歉,之前的代码有误。ComboBox 控件本身并不支持多列显示。在 WinForms 中实现多列下拉框需要使用其他控件或自定义绘制。
以下是一个使用自定义绘制和 DataGridView 控件的示例代码来实现多列下拉框的功能:
```csharp
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
public class MultiColumnComboBox : ComboBox
{
private DataGridView dataGridView; // 用于显示下拉列表的 DataGridView 控件
private bool isDroppedDown; // 标识下拉列表是否已展开
public MultiColumnComboBox()
{
InitializeDataGridView();
this.DropDown += MultiColumnComboBox_DropDown;
this.DropDownClosed += MultiColumnComboBox_DropDownClosed;
this.LostFocus += MultiColumnComboBox_LostFocus;
}
private void InitializeDataGridView()
{
dataGridView = new DataGridView();
dataGridView.AutoGenerateColumns = false;
dataGridView.AllowUserToAddRows = false;
dataGridView.AllowUserToDeleteRows = false;
dataGridView.RowHeadersVisible = false;
dataGridView.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
// 添加列
dataGridView.Columns.Add("Column1", "Column 1");
dataGridView.Columns.Add("Column2", "Column 2");
// 设置列宽度
dataGridView.Columns[0].Width = 100;
dataGridView.Columns[1].Width = 100;
// 将 DataGridView 控件添加到 ComboBox 的 Controls 集合中
this.Controls.Add(dataGridView);
}
private void MultiColumnComboBox_DropDown(object sender, EventArgs e)
{
if (this.Items.Count > 0 && !isDroppedDown)
{
int comboBoxHeight = this.Height;
int comboBoxWidth = this.Width;
// 设置下拉列表的位置和尺寸
dataGridView.Location = new Point(this.Location.X, this.Location.Y + comboBoxHeight);
dataGridView.Size = new Size(comboBoxWidth, this.PreferredHeight * 5);
dataGridView.DataSource = GetDataSource(); // 将数据源绑定到 DataGridView
dataGridView.CellClick += DataGridView_CellClick;
dataGridView.KeyDown += DataGridView_KeyDown;
isDroppedDown = true;
dataGridView.Focus();
}
}
private void MultiColumnComboBox_DropDownClosed(object sender, EventArgs e)
{
if (isDroppedDown)
{
dataGridView.CellClick -= DataGridView_CellClick;
dataGridView.KeyDown -= DataGridView_KeyDown;
isDroppedDown = false;
this.Focus();
}
}
private void MultiColumnComboBox_LostFocus(object sender, EventArgs e)
{
if (isDroppedDown)
{
dataGridView.CellClick -= DataGridView_CellClick;
dataGridView.KeyDown -= DataGridView_KeyDown;
isDroppedDown = false;
}
}
private void DataGridView_CellClick(object sender, DataGridViewCellEventArgs e)
{
if (e.RowIndex >= 0 && e.RowIndex < dataGridView.Rows.Count && e.ColumnIndex >= 0 && e.ColumnIndex < dataGridView.Columns.Count)
{
this.SelectedItem = dataGridView.Rows[e.RowIndex].Cells[e.ColumnIndex].Value;
this.Text = this.SelectedItem.ToString();
this.DroppedDown = false;
}
}
private void DataGridView_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
if (dataGridView.SelectedCells.Count > 0)
{
int rowIndex = dataGridView.SelectedCells[0].RowIndex;
int columnIndex = dataGridView.SelectedCells[0].ColumnIndex;
this.SelectedItem = dataGridView.Rows[rowIndex].Cells[columnIndex].Value;
this.Text = this.SelectedItem.ToString();
this.DroppedDown = false;
}
}
}
private object GetDataSource()
{
List<object[]> dataSource = new List<object[]>();
// 添加数据到数据源
dataSource.Add(new object[] { "Item 1 Column 1", "Item 1 Column 2" });
dataSource.Add(new object[] { "Item 2 Column 1", "Item 2 Column 2" });
dataSource.Add(new object[] { "Item 3 Column 1", "Item 3 Column 2" });
return dataSource;
}
}
```
然后,在您的 WinForms 窗体中使用这个自定义控件:
```csharp
private void Form1_Load(object sender, EventArgs e)
{
// 创建自定义的 MultiColumnComboBox 控件
MultiColumnComboBox multiColumnComboBox = new MultiColumnComboBox();
multiColumnComboBox.Location = new Point(50, 50);
multiColumnComboBox.Size = new Size(200, 30);
// 添加数据到下拉列表
multiColumnComboBox.Items.Add("Item 1");
multiColumnComboBox.Items.Add("Item 2");
multiColumnComboBox.Items.Add("Item 3");
// 将自定义控件添加到窗体中
this.Controls.Add(multiColumnComboBox);
}
```
这样,您就可以在 WinForms 窗体中使用自定义的 MultiColumnComboBox 控件,它可以显示多列的下拉列表项。请根据您的需求修改和调整代码。希望对您有所帮助!
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