我在这段代码中遇到了问题:
NSDictionary * imagen = [[NSDictionary alloc] initWithDictionary:[envio resultValue]];
NSString *imagenS = [imagen valueForKey:@"/Result"];
[Base64 initialize];
NSData * imagenDecode = [Base64 decode:imagenS];
NSLog(@"%@", [imagenS length]);
//SAVE IMAGE
NSArray *sysPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
NSString *docDirectory = [sysPaths objectAtIndex:0];
NSString *filePath = [NSString stringWithFormat:@"%@david.png",docDirectory];
[imagenDecode writeToFile:filePath atomically:YES];
[envio resultValue] --> 返回一个包含一张图片以 Base 64 编码的 NSDictionary。
我想要解码并保存这张图片,但在我的控制台上显示了以下消息:
2011-08-23 20:15:36.539 WSStub[39226:a0f] -[NSCFDictionary length]: unrecognized selector sent to instance 0xd00ee0
Base 64编码是:
//
// Base64.m
// CryptTest
//
// Created by Kiichi Takeuchi on 4/20/10.
// Copyright 2010 ObjectGraph LLC. All rights reserved.
//
#import "Base64.h"
@implementation Base64
#define ArrayLength(x) (sizeof(x)/sizeof(*(x)))
static char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static char decodingTable[128];
+ (void) initialize
{
if (self == [Base64 class])
{
memset(decodingTable, 0, ArrayLength(decodingTable));
for (NSInteger i = 0; i < ArrayLength(encodingTable); i++) {
decodingTable[encodingTable[i]] = i;
}
}
}
+ (NSData*) decode:(const char*) string length:(NSInteger) inputLength
{
if ((string == NULL) || (inputLength % 4 != 0))
{
return nil;
}
while (inputLength > 0 && string[inputLength - 1] == '=')
{
inputLength--;
}
NSInteger outputLength = inputLength * 3 / 4;
NSMutableData* data = [NSMutableData dataWithLength:outputLength];
uint8_t* output = data.mutableBytes;
NSInteger inputPoint = 0;
NSInteger outputPoint = 0;
while (inputPoint < inputLength)
{
char i0 = string[inputPoint++];
char i1 = string[inputPoint++];
char i2 = inputPoint < inputLength ? string[inputPoint++] : 'A'; /* 'A' will decode to \0 */
char i3 = inputPoint < inputLength ? string[inputPoint++] : 'A';
output[outputPoint++] = (decodingTable[i0] << 2) | (decodingTable[i1] >> 4);
if (outputPoint < outputLength)
{
output[outputPoint++] = ((decodingTable[i1] & 0xf) << 4) | (decodingTable[i2] >> 2);
}
if (outputPoint < outputLength)
{
output[outputPoint++] = ((decodingTable[i2] & 0x3) << 6) | decodingTable[i3];
}
}
return data;
}
+ (NSData*) decode:(NSString*) string
{
return [self decode:[string cStringUsingEncoding:NSASCIIStringEncoding] length:[string length]];
}
@end
imagenS
是一个NSDictionary
而不是NSString
。你能把打印imagen
的结果发出来吗? - albertamg