checkedlistbox控件也是我们常用的控件，我们仿照上一篇checkbox的例程，这回用checkedlistbox来实现
本来以为是很容易实现的，结果发现想让功能做的完善以下，中间有许多坑需要填，下面我们一起来看一下吧
1.界面布局
界面布局如下
具体的布局代码就不贴了，总之就是在在上一篇的基础上使用checkedlistbox来实现全选，并新增了删除和添加的功能
2.用法示例
需要注意的有这么几点
1.事件顺序
当我们点击某一项的时候，checkedlistbox调用事件的顺序是这样的
ItemCheck -> SelectedValueChanged -> SelectedIndexChanged
2.点击空白
如上图所示，当我们已经选中一项的时候，再点击空白处，这一项的状态依然会改变，避免的方法可以参考这篇博文
CheckedListBox 当中项的状态改变
3.双击事件DoubleClick
如果我们某一项点击的比较快，会触发DoubleClick事件，这时候全选框状态和是否全选的状态会不一致，我们需要在这个事件里面重新进行检测
4.全选框状态
如上一篇CheckBox所述，全选按钮只能在Click事件里面进行处理，否则会出现事件嵌套
当我们点击全选按钮的时候，checkedlistbox会检测到我们点击的是空白，但是这时候我们检测全选框状态的时候，其状态并未改变，导致我们无法区分是点击了空白还是点击了全选框，所以只能单独设置个变量来判断是否点击了全选按钮
实现的时候遇到的问题基本上就是上面几条，大家可以自己实现下，因该会遇到不少问题，下面来看看具体的实现代码
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;namespace WindowsFormsApplication1
{public partial class FormMain : Form{public FormMain(ArrayList arrip_list){InitializeComponent();}private void buttonShow_Click(object sender, EventArgs e){string sb = "您的兴趣爱好是 ";for (int i = 0; i < checkedListBox1.Items.Count; i++){if (checkedListBox1.GetItemChecked(i) == true){sb = sb + checkedListBox1.GetItemText(checkedListBox1.Items[i]) + ",";}}label2.Text = "" + sb;}private void checkedListBox1_SelectedValueChanged(object sender, EventArgs e){CheckedListBox clb = sender as CheckedListBox;点击空白处会触发该事件，如果之前没有选中任何项，则index为-1if (clb.SelectedIndex != -1){int SelectCount = 0;if (bIsSelectAll == false && clb.GetItemChecked(clb.SelectedIndex) == true){for (int i = 0; i < clb.Items.Count; i++){if (clb.GetItemChecked(i) == true){SelectCount++;}}if (SelectCount == clb.Items.Count){checkBoxSelectAll.CheckState = CheckState.Checked;//Console.WriteLine("Checked");}}else if (bIsSelectAll == false && clb.GetItemChecked(clb.SelectedIndex) == false){checkBoxSelectAll.CheckState = CheckState.Unchecked;//Console.WriteLine("UnChecked");}}//Console.WriteLine("Value Changed");//这里为了避免点击空白处依然会更改之前的选中项，每次都将index清空为-1//clb.SelectedIndex = -1;}//这里单独个变量用于记录全选按钮是否按下//如之前CheckBox所述，全选按钮只能在Click事件里面进行处理，否则会出现事件嵌套//但是在Click事件里面的问题就是，在其他地方获取全选按钮的状态时候，状态并未改变//导致在Checklistbox判断是点击空白还是点击全选的时候无法进行判断private bool bIsSelectAll = false;private void checkBoxSelectAll_Click(object sender, EventArgs e){CheckBox cb = sender as CheckBox;if (cb.CheckState == CheckState.Checked)//if (checkBoxSelectAll.CheckState == CheckState.Checked){bIsSelectAll = true;for (int i = 0; i < checkedListBox1.Items.Count; i++){//这里需要手动设置以下索引，否则在直接设置某项状态的时候//SelectedItem是nullcheckedListBox1.SelectedIndex = i;checkedListBox1.SetItemChecked(i, true);}}else if (cb.CheckState == CheckState.Unchecked){bIsSelectAll = true;for (int i = 0; i < checkedListBox1.Items.Count; i++){//这里需要手动设置以下索引，否则在直接设置某项状态的时候//SelectedItem是nullcheckedListBox1.SelectedIndex = i;checkedListBox1.SetItemChecked(i, false);}}bIsSelectAll = false;//这里清空下索引，否则每次点击后最后一项都会被选中//清空索引后，让所有项都取消反蓝checkedListBox1.SelectedIndex = -1;}private ArrayList listM_moteeui = new ArrayList();private void checkedListBox1_ItemCheck(object sender, ItemCheckEventArgs e){CheckedListBox clb = sender as CheckedListBox;//检测是否点击到空白的方法，可以参考下面这篇博文//https://blog.csdn.net/apgk1/article/details/50787435//判断如果点击的坐标是空白的地方则不更改值if (bIsSelectAll == false && clb.IndexFromPoint(clb.PointToClient(Cursor.Position).X,clb.PointToClient(Cursor.Position).Y) == -1){e.NewValue = e.CurrentValue;}else //这边开始判断集合当中是不是已经有ID，如果没有就加入{string temp = clb.SelectedItem.ToString();if (!listM_moteeui.Contains(temp)){listM_moteeui.Add(temp);}else{listM_moteeui.Remove(temp);}}}private void checkedListBox1_SelectedIndexChanged(object sender, EventArgs e){CheckedListBox clb = sender as CheckedListBox;}private void checkedListBox1_DoubleClick(object sender, EventArgs e){CheckedListBox clb = sender as CheckedListBox;//这里需要在DoubleClick中重新判断以下，因为如果点击的太快//DoubleClick事件触发，全选按钮和checklistbox的状态会不一致if (clb.SelectedIndex != -1){int SelectCount = 0;if (clb.GetItemChecked(clb.SelectedIndex) == true){for (int i = 0; i < clb.Items.Count; i++){if (clb.GetItemChecked(i) == true){SelectCount++;}}if (SelectCount == clb.Items.Count){checkBoxSelectAll.CheckState = CheckState.Checked;}}else if (clb.GetItemChecked(clb.SelectedIndex) == false){checkBoxSelectAll.CheckState = CheckState.Unchecked;}}}private void buttonDelete_Click(object sender, EventArgs e){if (checkedListBox1.SelectedIndex != -1){//删除选中项checkedListBox1.Items.Remove(checkedListBox1.GetItemText(checkedListBox1.Items[checkedListBox1.SelectedIndex]));//重新检查是否需要选中全选按钮int SelectCount = 0;for (int i = 0; i < checkedListBox1.Items.Count; i++){if (checkedListBox1.GetItemChecked(i) == true){SelectCount++;}}if (SelectCount == checkedListBox1.Items.Count){checkBoxSelectAll.CheckState = CheckState.Checked;//Console.WriteLine("Checked");}else{checkBoxSelectAll.CheckState = CheckState.Unchecked;}}}private void buttonAdd_Click(object sender, EventArgs e){//如果内容不为空if (textBoxAdd.Text != ""){//添加新内容到checklistboxcheckedListBox1.Items.Add(textBoxAdd.Text);//清空内容textBoxAdd.Text = "";}}}
}
不足之处希望能多批评指正，谢谢
