C#多选下拉菜单自定义控件

C#在winform项目中 多选下拉菜单自定义控件 。

由 ComboBox 和 CheckedListBox 组合形成。

效果：

 

自定义控件代码

MultiComboBox.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;namespace HL_MultiComboBox
{public partial class MultiComboBox : UserControl{public ComboBox ComboBox = new ComboBox();public CheckedListBox CheckedListBox { get; set; }  //为选项赋值的接口public List<string> SelectedItems1 { get; set; }  //传递已选择项目的接口public MultiComboBox(){InitializeComponent();this.VerticalScroll.Enabled = true;this.AutoSize = true;CheckedListBox=new CheckedListBox();CheckedListBox.CheckOnClick = true;CheckedListBox.Visible = false;ComboBox = new ComboBox();ComboBox.Width = 150;ComboBox.DrawMode = DrawMode.OwnerDrawFixed;ComboBox.IntegralHeight = false;ComboBox.DroppedDown = false;ComboBox.DropDownHeight = 1;ComboBox.DropDownStyle = ComboBoxStyle.DropDown;ComboBox.AutoCompleteSource = AutoCompleteSource.ListItems;CheckedListBox.MouseUp += MouseUp1;CheckedListBox.MouseLeave += MouseLeave1;ComboBox.MouseDown += MouseDown1;ComboBox.DropDown += MouseLeave2;this.Controls.Add(ComboBox);   //添加控件
        }//
        #region 订阅方法模块//
        private void MouseLeave1(object sender, EventArgs e)  //鼠标离开CheckedListBox，隐藏CheckedListBox
        {CheckedListBox.Hide();}private void MouseLeave2(object sender, EventArgs e)  //ComboBox下拉时，显示下拉框
        {// 显示下拉框CheckedListBox.Width = ComboBox.Width;CheckedListBox.Size = new Size(ComboBox.DropDownWidth, CheckedListBox.Items.Count * 18);CheckedListBox.Location = new Point(ComboBox.Left, ComboBox.Height);Controls.Add(CheckedListBox);CheckedListBox.Visible = true;}private void MouseUp1(object sender, EventArgs e)  //在CheckedListBox中选择后，在ComboBox中显示相应项目
        {var list = new List<string>();foreach (var v in CheckedListBox.CheckedItems)  //将选择的项目加入list
            {list.Add(v.ToString());}ComboBox.Text = String.Join(",", list);SelectedItems1 = list;  //把选项赋给传递接口
        }private void MouseDown1(object sender, EventArgs e) //在ComboBox的下拉三角按下鼠标时，不显示ComboBox的下拉框，显示CheckedListBox当作其下拉框
        {ComboBox.DroppedDown = false;}#endregion }
}

MultiComboBox.Designer.cs

       #region 组件设计器生成的代码/// <summary>/// 设计器支持所需的方法 - 不要/// 使用代码编辑器修改此方法的内容。/// </summary>private void InitializeComponent(){this.SuspendLayout();// // MultiComboBox// this.Name = "MultiComboBox";this.Size = new System.Drawing.Size(278, 50);this.ResumeLayout(false);}#endregion

使用方法

拖 multComboBox 控件至窗体中 名为 multiComboBox1

       private void Form1_Load(object sender, EventArgs e){this.multiComboBox1.ComboBox.Width = 300;//为下拉菜单添加选项this.multiComboBox1.CheckedListBox.Items.Add("1");this.multiComboBox1.CheckedListBox.Items.Add("2");this.multiComboBox1.CheckedListBox.Items.Add("3");this.multiComboBox1.CheckedListBox.Items.Add("4");this.multiComboBox1.CheckedListBox.Items.Add("5");this.multiComboBox1.CheckedListBox.Items.Add("6");this.multiComboBox1.CheckedListBox.Items.Add("7");this.multiComboBox1.CheckedListBox.Items.Add("8");this.multiComboBox1.CheckedListBox.Items.Add("9");this.multiComboBox1.CheckedListBox.Items.Add("10");}private void button1_Click(object sender, EventArgs e){var strSelected = multiComboBox1.SelectedItems1;string strResult = string.Join(",", strSelected);MessageBox.Show(strResult);}