Throws an exception if the System.Windows.Forms.DataGrid does not have a valid data source, or if this column is not mapped to a valid property in the data source.是什么意思_Throws an exception if the System.Windows.Forms.DataGrid does not have a valid data source, or if this column is not mapped to a valid property in the data source.在线翻译_英语_读音_用法_例句