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

1 #import <Foundation/Foundation.h>

2 

3 @interface Base64AndImageHelp : NSObject

4 - (NSString*)encodeURL:(NSString *)string;

5 +(id)mydataWithBase64EncodedString:(NSString *)string ;

6 @end

Base64AndImageHelp.h

然后是.M文件

  1 #import "Base64AndImageHelp.h"

  2 @interface NSData (MBBase64)

  3 

  4 + (id)dataWithBase64EncodedString:(NSString *)string;

  5 - (NSString *)base64Encoding;

  6 

  7 @end

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

  9 

 10 @implementation NSData (MBBase64)

 11 

 12 + (id)dataWithBase64EncodedString:(NSString *)string {

 13     if (string == nil)

 14         [NSException raise:NSInvalidArgumentException format:@""];

 15     

 16     if ([string length] == 0)

 17         return [NSData data];

 18     

 19     static char *decodingTable = NULL;

 20     

 21     if (decodingTable == NULL) {

 22         decodingTable = malloc(256);

 23         if (decodingTable == NULL)

 24             return nil;

 25         memset(decodingTable, CHAR_MAX, 256);

 26         NSUInteger i;

 27         for (i = 0; i < 64; i++)

 28             decodingTable[(short)encodingTable[i]] = i;

 29     }

 30     

 31     const char *characters = [string cStringUsingEncoding:NSASCIIStringEncoding];

 32     if (characters == NULL)

 33         return nil;

 34     char *bytes = malloc((([string length] + 3) / 4) * 3);

 35     if (bytes == NULL)

 36         return nil;

 37     

 38     NSUInteger length = 0;

 39     NSUInteger i = 0;

 40     

 41     while (YES) {

 42         char buffer[4];

 43         short bufferLength;

 44         for (bufferLength = 0; bufferLength < 4; i++) {

 45             if (characters[i] == '\0')

 46                 break;

 47             if (isspace(characters[i]) || characters[i] == '=')

 48                 continue;

 49             buffer[bufferLength] = decodingTable[(short)characters[i]];

 50             if (buffer[bufferLength++] == CHAR_MAX) {

 51                 free(bytes);

 52                 return nil;

 53             }

 54         }

 55         

 56         if (bufferLength == 0)

 57             break;

 58         if (bufferLength == 1) {

 59             free(bytes);

 60             return nil;

 61         }

 62         

 63         bytes[length++] = (buffer[0] << 2) | (buffer[1] >> 4);

 64         if (bufferLength > 2)

 65             bytes[length++] = (buffer[1] << 4) | (buffer[2] >> 2);

 66         if (bufferLength > 3)

 67             bytes[length++] = (buffer[2] << 6) | buffer[3];

 68     }

 69     

 70     realloc(bytes, length);

 71     return [NSData dataWithBytesNoCopy:bytes length:length];

 72 }

 73 

 74 - (NSString *)base64Encoding {

 75     if ([self length] == 0)

 76         return @"";

 77     

 78     char *characters = malloc((([self length] + 2) / 3) * 4);

 79     if (characters == NULL)

 80         return nil;

 81     

 82     NSUInteger length = 0;

 83     NSUInteger i = 0;

 84     

 85     while (i < [self length]) {

 86         char buffer[3] = {0,0,0};

 87         short bufferLength = 0;

 88         while (bufferLength < 3 && i < [self length])

 89             buffer[bufferLength++] = ((char *)[self bytes])[i++];

 90         characters[length++] = encodingTable[(buffer[0] & 0xFC) >> 2];

 91         characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];

 92         if (bufferLength > 1)

 93             characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];

 94         else characters[length++] = '=';

 95         if (bufferLength > 2)

 96             characters[length++] = encodingTable[buffer[2] & 0x3F];

 97         else characters[length++] = '=';

 98     }

 99     

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

101 }

102 

103 @end

104 @implementation Base64AndImageHelp

105 - (NSString*)encodeURL:(NSString *)string

106 {

107     NSString *newString = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes( kCFAllocatorDefault, (CFStringRef)string, NULL, CFSTR(":/?#[]@!$ &'()*+,;=\"<>%{}|\\^~`"),kCFStringEncodingUTF8));

108     if (newString) {

109         return newString;

110     }

111     return @"";

112     

113     

114 }

115 + (id)mydataWithBase64EncodedString:(NSString *)string {

116     if (string == nil)

117         [NSException raise:NSInvalidArgumentException format:@""];

118     

119     if ([string length] == 0)

120         return [NSData data];

121     

122     static char *decodingTable = NULL;

123     

124     if (decodingTable == NULL) {

125         decodingTable = malloc(256);

126         if (decodingTable == NULL)

127             return nil;

128         memset(decodingTable, CHAR_MAX, 256);

129         NSUInteger i;

130         for (i = 0; i < 64; i++)

131             decodingTable[(short)encodingTable[i]] = i;

132     }

133     

134     const char *characters = [string cStringUsingEncoding:NSASCIIStringEncoding];

135     if (characters == NULL)

136         return nil;

137     char *bytes = malloc((([string length] + 3) / 4) * 3);

138     if (bytes == NULL)

139         return nil;

140     

141     NSUInteger length = 0;

142     NSUInteger i = 0;

143     

144     while (YES) {

145         char buffer[4];

146         short bufferLength;

147         for (bufferLength = 0; bufferLength < 4; i++) {

148             if (characters[i] == '\0')

149                 break;

150             if (isspace(characters[i]) || characters[i] == '=')

151                 continue;

152             buffer[bufferLength] = decodingTable[(short)characters[i]];

153             if (buffer[bufferLength++] == CHAR_MAX) {

154                 free(bytes);

155                 return nil;

156             }

157         }

158         

159         if (bufferLength == 0)

160             break;

161         if (bufferLength == 1) {

162             free(bytes);

163             return nil;

164         }

165         

166         bytes[length++] = (buffer[0] << 2) | (buffer[1] >> 4);

167         if (bufferLength > 2)

168             bytes[length++] = (buffer[1] << 4) | (buffer[2] >> 2);

169         if (bufferLength > 3)

170             bytes[length++] = (buffer[2] << 6) | buffer[3];

171     }

172     

173     realloc(bytes, length);

174     return [NSData dataWithBytesNoCopy:bytes length:length];

175 }

176 @end

Base64AndImageHelp.m

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