iphone - NSString 的 Base64 编码

Question

<分区>

Answer 1

这可以通过实现一个用于 base64 转换的类方法来完成，下面的代码用于转换..

+ (NSString*)base64forData:(NSData*)theData 
{
    const uint8_t* input = (const uint8_t*)[theData bytes];
    NSInteger length = [theData length];

    static char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

    NSMutableData* data = [NSMutableData dataWithLength:((length + 2) / 3) * 4];
    uint8_t* output = (uint8_t*)data.mutableBytes;

    NSInteger i;
    for (i=0; i < length; i += 3) {
        NSInteger value = 0;
        NSInteger j;
        for (j = i; j < (i + 3); j++) {
            value <<= 8;

            if (j < length) {
                value |= (0xFF & input[j]);
            }
        }

        NSInteger theIndex = (i / 3) * 4;
        output[theIndex + 0] =                    table[(value >> 18) & 0x3F];
        output[theIndex + 1] =                    table[(value >> 12) & 0x3F];
        output[theIndex + 2] = (i + 1) < length ? table[(value >> 6)  & 0x3F] : '=';
        output[theIndex + 3] = (i + 2) < length ? table[(value >> 0)  & 0x3F] : '=';
    }

    return [[[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding] autorelease];
}

并在您的 URL 请求中添加以下代码以发送用户名和密码以进行授权...

[请求 addValue:[NSString stringWithFormat:@"Basic %@",[className base64forData:[[NSString stringWithFormat:@"%@:%@",UsernameString,passwordString] dataUsingEncoding: NSUTF8StringEncoding]]] forHTTPHeaderField:@"授权”];