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我尝试将图像放入 中JSON，但如何将图像放入 中NSData？我得到的只是__NSCFArray我的二进制数据，但是如何转换它呢？

编辑：这是我在 json 中的结果

Printing description of resDict:
{
Details = "Foo";
GroupingInfo = LRU;
HeaderLeft = "Bar";
HeaderRight = "Foo";
Id = "cb217aeb-14e3-4bd5-8895-3217238deb2c";
IsGray = 0;
AnotherId = "<null>";
MainImage =     (
    137,
    80,
    78,
    71,
 ...
4

1 回答 1

2

您首先必须解析 JSON，然后将二进制部分放入 NSData。UIImage 有一种方法可以将 NSData 更改为图像

UIImage *myimage = [UIImage imageWithData:mydata];

更新：（希望没人介意）在自己做了一个这样的演示后，NSJSONSerialization 总是返回字符串，并且在下面进行了一个小的来回对话之后。我尝试将图像作为 Base64 编码字符串发送并使用 base64 解码作为数据读回。这是一种魅力。

这是我使用的代码（因为它适用于所有 iOS 版本，从 3.0 及更高版本）：

NSData+PHBase64.h

@interface NSData (PHBase64)

+ (id)dataWithBase64EncodedString:(NSString *)string;     //  Padding '=' characters are optional. Whitespace is ignored.
- (NSString *)base64Encoding;
@end

NSData+PHBase64.m

#import "NSData+Base64.h"


static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";


@implementation NSData (PHBase64)

+ (id)dataWithBase64EncodedString:(NSString *)string;
{
    if (string == nil)
        [NSException raise:NSInvalidArgumentException format:nil];
    if ([string length] == 0)
        return [NSData data];

    static char *decodingTable = NULL;
    if (decodingTable == NULL)
    {
        decodingTable = malloc(256);
        if (decodingTable == NULL)
            return nil;
        memset(decodingTable, CHAR_MAX, 256);
        NSUInteger i;
        for (i = 0; i < 64; i++)
            decodingTable[(short)encodingTable[i]] = i;
    }

    const char *characters = [string cStringUsingEncoding:NSASCIIStringEncoding];
    if (characters == NULL)     //  Not an ASCII string!
        return nil;
    char *bytes = malloc((([string length] + 3) / 4) * 3);
    if (bytes == NULL)
        return nil;
    NSUInteger length = 0;

    NSUInteger i = 0;
    while (YES)
    {
        char buffer[4];
        short bufferLength;
        for (bufferLength = 0; bufferLength < 4; i++)
        {
            if (characters[i] == '\0')
                break;
            if (isspace(characters[i]) || characters[i] == '=')
                continue;
            buffer[bufferLength] = decodingTable[(short)characters[i]];
            if (buffer[bufferLength++] == CHAR_MAX)      //  Illegal character!
            {
                free(bytes);
                return nil;
            }
        }

        if (bufferLength == 0)
            break;
        if (bufferLength == 1)      //  At least two characters are needed to produce one byte!
        {
            free(bytes);
            return nil;
        }

        //  Decode the characters in the buffer to bytes.
        bytes[length++] = (buffer[0] << 2) | (buffer[1] >> 4);
        if (bufferLength > 2)
            bytes[length++] = (buffer[1] << 4) | (buffer[2] >> 2);
        if (bufferLength > 3)
            bytes[length++] = (buffer[2] << 6) | buffer[3];
    }

    realloc(bytes, length);
    return [NSData dataWithBytesNoCopy:bytes length:length];
}

- (NSString *)base64Encoding;
{
    if ([self length] == 0)
        return @"";

  char *characters = malloc((([self length] + 2) / 3) * 4);
    if (characters == NULL)
        return nil;
    NSUInteger length = 0;

    NSUInteger i = 0;
    while (i < [self length])
    {
        char buffer[3] = {0,0,0};
        short bufferLength = 0;
        while (bufferLength < 3 && i < [self length])
            buffer[bufferLength++] = ((char *)[self bytes])[i++];

        //  Encode the bytes in the buffer to four characters, including padding "=" characters if necessary.
        characters[length++] = encodingTable[(buffer[0] & 0xFC) >> 2];
        characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];
        if (bufferLength > 1)
            characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];
        else characters[length++] = '=';
        if (bufferLength > 2)
            characters[length++] = encodingTable[buffer[2] & 0x3F];
        else characters[length++] = '=';    
    }

    return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];
}

@end
于 2012-10-26T13:42:30.670 回答