拖放打开文件，C#获取文件的目录或路径信息，只需拖动文件到主窗体中，即可获取到所选文件所在的目录路径，弹出窗口告诉你-Drag-and-drop to open the file C# Get file directory or path information, simply drag the file to the main form, you can obtain the directory path to the selected file, the pop-up window to t