IOS开发---菜鸟学习之路--（十四）-将BASE64图片转换成Image

本文基本全部都是代码

首先是.H文件

#import <Foundation/Foundation.h>

@interface Base64AndImageHelp : NSObject
- (NSString*)encodeURL:(NSString *)string;
+(id)mydataWithBase64EncodedString:(NSString *)string ;
@end

然后是.M文件

#import "Base64AndImageHelp.h"
@interface NSData (MBBase64)

+ (id)dataWithBase64EncodedString:(NSString *)string;
- (NSString *)base64Encoding;

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

@implementation NSData (MBBase64)

+ (id)dataWithBase64EncodedString:(NSString *)string {
    if (string == nil)
        [NSException raise:NSInvalidArgumentException format:@""];
    
    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)
        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] == '')
                break;
            if (isspace(characters[i]) || characters[i] == '=')
                continue;
            buffer[bufferLength] = decodingTable[(short)characters[i]];
            if (buffer[bufferLength++] == CHAR_MAX) {
                free(bytes);
                return nil;
            }
        }
        
        if (bufferLength == 0)
            break;
        if (bufferLength == 1) {
            free(bytes);
            return nil;
        }
        
        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++];
        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
@implementation Base64AndImageHelp
- (NSString*)encodeURL:(NSString *)string
{
    NSString *newString = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes( kCFAllocatorDefault, (CFStringRef)string, NULL, CFSTR(":/?#[]@!$ &'()*+,;="<>%{}|\^~`"),kCFStringEncodingUTF8));
    if (newString) {
        return newString;
    }
    return @"";
    
    
}
+ (id)mydataWithBase64EncodedString:(NSString *)string {
    if (string == nil)
        [NSException raise:NSInvalidArgumentException format:@""];
    
    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)
        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] == '')
                break;
            if (isspace(characters[i]) || characters[i] == '=')
                continue;
            buffer[bufferLength] = decodingTable[(short)characters[i]];
            if (buffer[bufferLength++] == CHAR_MAX) {
                free(bytes);
                return nil;
            }
        }
        
        if (bufferLength == 0)
            break;
        if (bufferLength == 1) {
            free(bytes);
            return nil;
        }
        
        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];
}
@end

完成该类后就可以在其他类中使用了

NSData *newimage=[Base64AndImageHelp mydataWithBase64EncodedString:base64的STRING];

UIImage *newjiaban=[[UIImage alloc] initWithData:newimage];

ok这样就完成拉