Winform 下拉带Checkbox 功能

C:\Users\Administrator\Desktop\Code\DemoApp\bin\Debug\DemoApp.exe C:\Users\Administrator\Desktop\Code\DemoApp\bin\Debug\DemoApp.pdb C:\Users\Administrator\Desktop\Code\DemoApp\bin\Debug\CheckBoxComboBox.dll C:\Users\Administrator\Desktop\Code\DemoApp\bin\Debug\CheckBoxComboBox.pdb C:\Users\Administrator\Desktop\Code\DemoApp\obj\Debug\DemoApp.csprojResolveAssemblyReference.cache C:\Users\Administrator\Desktop\Code\DemoApp\obj\Debug\DemoApp.Form1.resources C:\Users\Administrator\Desktop\Code\DemoApp\obj\Debug\DemoApp.Properties.Resources.resources C:\Users\Administrator\Desktop\Code\DemoApp\obj\Debug\DemoApp.csproj.GenerateResource.Cache C:\Users\Administrator\Desktop\Code\DemoApp\obj\Debug\DemoApp.exe C:\Users\Administrator\Desktop\Code\DemoApp\obj\Debug\DemoApp.pdb E:\下载内容\Code\Code\DemoApp\bin\Debug\DemoApp.exe E:\下载内容\Code\Code\DemoApp\bin\Debug\DemoApp.pdb E:\下载内容\Code\Code\DemoApp\bin\Debug\CheckBoxComboBox.dll E:\下载内容\Code\Code\DemoApp\bin\Debug\CheckBoxComboBox.pdb E:\下载内容\Code\Code\DemoApp\obj\Debug\DemoApp.csproj.AssemblyReference.cache E:\下载内容\Code\Code\DemoApp\obj\Debug\DemoApp.Form1.resources E:\下载内容\Code\Code\DemoApp\obj\Debug\DemoApp.Properties.Resources.resources E:\下载内容\Code\Code\DemoApp\obj\Debug\DemoApp.csproj.GenerateResource.cache E:\下载内容\Code\Code\DemoApp\obj\Debug\DemoApp.csproj.CoreCompileInputs.cache E:\下载内容\Code\Code\DemoApp\obj\Debug\DemoApp.csproj.CopyComplete E:\下载内容\Code\Code\DemoApp\obj\Debug\DemoApp.exe E:\下载内容\Code\Code\DemoApp\obj\Debug\DemoApp.pdb