在datetimepicker C＃中读取自定义格式

Question

I want to do dateTimePicker to choose and read only year. This is my code, but when on third row where is dateTimePicker1.Value it's someone else because when i open file is show me hour, date, month and year. I trying to change value with customformat but make me mistake and want to change to string. Whan I change to string like: string dt = dateTimePicker1.CustomFormat; started it give me the same result like value. Where is the problem?

dateTimePicker1.Format = DateTimePickerFormat.Custom; //1
                dateTimePicker1.CustomFormat = "yyyy"; //2
    DateTime dt = dateTimePicker1.Value; //3
                fp.Seek(0, SeekOrigin.End); //4
                bw.Write(dt.ToString()); //5 

Answer 1

您只需要使用ToString方法：

dateTimePicker1.Value.ToString("yyyy");