How to encode NSData as base64? (iPhone/iPad)

问题

I'm trying to add a UIImage to an HTML email, however I'm having an issue. I have looked around at lots of other posts and they all state that I need to convert my NSData to base64, however the method they all suggest doesn't seem to exist anymore (unless I'm missing something?!).

Here is the code I have so far:

UIImage *mapImage = [mapViewController convertMapToImage];
NSData *imageData = [NSData dataWithData:UIImagePNGRepresentation(mapImage)];
NSString *base64String = // [imageData base64EncodedString];   --- this method isn't recognised

Please can someone help me out?

回答1:

The method you are trying to use doesn come with default framework. You can add the NSData category to your project.

回答2:

+ (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];
}

来源：https://stackoverflow.com/questions/10584396/how-to-encode-nsdata-as-base64-iphone-ipad

标签

iphone

uiimage

base64

nsdata