zoukankan html css js c++ java

IOS开发---菜鸟学习之路--（十六）-将Image转换为Base64

我们直接在.m文件的引用头文件部分和 @interface AddPictureViewController ()

之间加入增加部分的代码

然后就可以使用图片转Base64了

#import "AddPictureViewController.h"

#import <QuartzCore/QuartzCore.h>

#import <QuartzCore/CoreAnimation.h>

#import <MobileCoreServices/UTCoreTypes.h>

  1 @interface NSData (MBBase64)
  2 
  3 + (id)dataWithBase64EncodedString:(NSString *)string;
  4 - (NSString *)base64Encoding;
  5 
  6 @end
  7 static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  8 
  9 @implementation NSData (MBBase64)
 10 
 11 + (id)dataWithBase64EncodedString:(NSString *)string {
 12     if (string == nil)
 13         [NSException raise:NSInvalidArgumentException format:@""];
 14     
 15     if ([string length] == 0)
 16         return [NSData data];
 17     
 18     static char *decodingTable = NULL;
 19     
 20     if (decodingTable == NULL) {
 21         decodingTable = malloc(256);
 22         if (decodingTable == NULL)
 23             return nil;
 24         memset(decodingTable, CHAR_MAX, 256);
 25         NSUInteger i;
 26         for (i = 0; i < 64; i++)
 27             decodingTable[(short)encodingTable[i]] = i;
 28     }
 29     
 30     const char *characters = [string cStringUsingEncoding:NSASCIIStringEncoding];
 31     if (characters == NULL)
 32         return nil;
 33     char *bytes = malloc((([string length] + 3) / 4) * 3);
 34     if (bytes == NULL)
 35         return nil;
 36     
 37     NSUInteger length = 0;
 38     NSUInteger i = 0;
 39     
 40     while (YES) {
 41         char buffer[4];
 42         short bufferLength;
 43         for (bufferLength = 0; bufferLength < 4; i++) {
 44             if (characters[i] == '')
 45                 break;
 46             if (isspace(characters[i]) || characters[i] == '=')
 47                 continue;
 48             buffer[bufferLength] = decodingTable[(short)characters[i]];
 49             if (buffer[bufferLength++] == CHAR_MAX) {
 50                 free(bytes);
 51                 return nil;
 52             }
 53         }
 54         
 55         if (bufferLength == 0)
 56             break;
 57         if (bufferLength == 1) {
 58             free(bytes);
 59             return nil;
 60         }
 61         
 62         bytes[length++] = (buffer[0] << 2) | (buffer[1] >> 4);
 63         if (bufferLength > 2)
 64             bytes[length++] = (buffer[1] << 4) | (buffer[2] >> 2);
 65         if (bufferLength > 3)
 66             bytes[length++] = (buffer[2] << 6) | buffer[3];
 67     }
 68     
 69     realloc(bytes, length);
 70     return [NSData dataWithBytesNoCopy:bytes length:length];
 71 }
 72 
 73 - (NSString *)base64Encoding {
 74     if ([self length] == 0)
 75         return @"";
 76     
 77     char *characters = malloc((([self length] + 2) / 3) * 4);
 78     if (characters == NULL)
 79         return nil;
 80     
 81     NSUInteger length = 0;
 82     NSUInteger i = 0;
 83     
 84     while (i < [self length]) {
 85         char buffer[3] = {0,0,0};
 86         short bufferLength = 0;
 87         while (bufferLength < 3 && i < [self length])
 88             buffer[bufferLength++] = ((char *)[self bytes])[i++];
 89         characters[length++] = encodingTable[(buffer[0] & 0xFC) >> 2];
 90         characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];
 91         if (bufferLength > 1)
 92             characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];
 93         else characters[length++] = '=';
 94         if (bufferLength > 2)
 95             characters[length++] = encodingTable[buffer[2] & 0x3F];
 96         else characters[length++] = '=';
 97     }
 98     
 99     return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES] ;
100 }
101 
102 @end

增加部分的代码

@interface AddPictureViewController ()

@end

具体的转换操作如下

NSData *mydata=UIImageJPEGRepresentation(image , 0.4);

NSString *pictureDataString=[mydata base64Encoding];

如果需要传递到后台的话尽量进行编码操作

编码部分的方法如下

1 - (NSString*)encodeURL:(NSString *)string
2 {
3     NSString *newString = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes( kCFAllocatorDefault, (CFStringRef)string, NULL, CFSTR(":/?#[]@!$ &'()*+,;="<>%{}|\^~`"),kCFStringEncodingUTF8));
4     if (newString) {
5         return newString;
6     }
7     return @"";
8 }

encodeURL

然后我们只需要像这样子使用就可以了

1 -(void)zhuanhuan:(id)sender
2 {
3     NSData *mydata=UIImageJPEGRepresentation(contentimageview.image , 0.4);
4     NSString *pictureDataString=[mydata base64Encoding];
5     NSString *image=[self encodeURL:pictureDataString];
6    // NSLog(pictureDataString);
7 }

View Code

这边再给大家提供一个在线转换工具大家可以直接在上面进行Image与Base64之间的转换

http://www.vgot.net/test/image2base64.php

查看全文

相关阅读:
WPF线程中获取控件的值和给控件赋值
 sublime text3 安装以及主要插件安装
 云服务IaaS，PaaS，SaaS
What is JSON
Core Java
英语单词及语义
 设置PyCharm创建文件时自动添加头文件
 【练习】字典的循环遍历：实现多层级节点存取
 字符串格式化
 常用数据类型的方法--str、int、list、dict

原文地址：https://www.cnblogs.com/PleaseInputEnglish/p/3486561.html