System.IO.Path.GetFullPath(openFileDialog1.FileName);//绝对路径
System.IO.Path.GetExtension(openFileDialog1.FileName); //文件扩展名
System.IO.Path.GetFileNameWithoutExtension(openFileDialog1.FileName);//文件名没有扩展名
System.IO.Path.GetFileName(openFileDialog1.FileName);//得到文件
System.IO.Path.GetDirectoryName(openFileDialog1.FileName);//得到路径