C#将base64编码的字符串转换成bitmap位图

Convert类的静态方法FromBase64String 可以讲base64编码的字符串反转为二进制数据byte[]格式，从而恢复编码后的bitmap位图

byte[] imageBytes = bmpAsString.Base64DecodeString();
using (FileStream fstrm = new FileStream(@"C:\recdcopy.bmp",FileMode.CreateNew, FileAccess.Write))
{
    using (BinaryWriter writer = new BinaryWriter(fstrm))
    {
        writer.Write(imageBytes);
    }
}