base64字符串与图片之间的转换

1.base64->图片

private void base64ToImg(){    string str="data:image/jpeg;base64,/9j/4AAQSkZJRg……";    int subStrIndex = str.IndexOf(";base64,") + 8;    string base64str=str..Substring(subStrIndex);    byte[] arr = Convert.FromBase64String(base64);    MemoryStream ms = new MemoryStream(arr);    System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(ms);    bmp.Save("@"C:\Img.jpg");    bmp.Dispose();    ms.Dispose();    ms.Close();}