C# 鼠标拖动显示矩形选框（winform程序）

E:\vs工程\demo\demo\bin\Debug\demo.exe E:\vs工程\demo\demo\bin\Debug\demo.pdb E:\vs工程\demo\demo\obj\Debug\demo.csprojResolveAssemblyReference.cache E:\vs工程\demo\demo\obj\Debug\demo.Form1.resources E:\vs工程\demo\demo\obj\Debug\demo.Properties.Resources.resources E:\vs工程\demo\demo\obj\Debug\demo.csproj.GenerateResource.Cache E:\vs工程\demo\demo\obj\Debug\demo.exe E:\vs工程\demo\demo\obj\Debug\demo.pdb C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\bin\Debug\demo.exe C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\bin\Debug\demo.pdb C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\obj\Debug\demo.csproj.AssemblyReference.cache C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\obj\Debug\demo.Form1.resources C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\obj\Debug\demo.Properties.Resources.resources C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\obj\Debug\demo.csproj.GenerateResource.cache C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\obj\Debug\demo.csproj.CoreCompileInputs.cache C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\obj\Debug\demo.exe C:\Users\Administrator\Desktop\winform开源项目\demo鼠标拖动画框框选框\demo\demo\obj\Debug\demo.pdb