MD5

---------------------------------图片稀释类-----------------------------------

#import <Foundation/Foundation.h>

#import <UIKit/UIKit.h>

@interface ReduceImageRatio :
NSObject

+ (UIImage *)imageWithMaxSide:(CGFloat)length sourceImage:(UIImage *)image;

@end

#import "ReduceImageRatio.h"

@implementation ReduceImageRatio

+ (UIImage *)imageWithMaxSide:(CGFloat)length sourceImage:(UIImage *)image{

CGFloat scale = [[UIScreen
mainScreen] scale];

CGSize imgSize =
GGSSizeReduce(image.size, length);

UIImage *img =
nil;

UIGraphicsBeginImageContextWithOptions(imgSize,
YES, scale);
// 创建一个 bitmap context

[image drawInRect:CGRectMake(0,
0, imgSize.width, imgSize.height)

blendMode:kCGBlendModeNormal
alpha:1.0];
// 将图片绘制到当前的 context
上

img = UIGraphicsGetImageFromCurrentImageContext();
// 从当前 context
中获取刚绘制的图片

UIGraphicsEndImageContext();

return img;

}

static CGSize GGSSizeReduce(CGSize size,
CGFloat limit) //
按比例减少尺寸

{

CGFloat max =
MAX(size.width, size.height);

if (max < limit) {

return size;

}

CGSize imgSize;

CGFloat ratio = size.height / size.width;

if (size.width > size.height) {

imgSize = CGSizeMake(limit, limit*ratio);

} else {

imgSize = CGSizeMake(limit/ratio, limit);

}

return imgSize;

}

@end

---------------------------------MD5类-----------------------------------

#import <Foundation/Foundation.h>

#import <UIKit/UIKit.h>

@interface Md5 : NSObject

+ (NSString *) md5:(NSString *)str;

@end

#import "Md5.h"

#import <CommonCrypto/CommonDigest.h>

@implementation Md5

+ (NSString *) md5:(NSString *)str

{

const char *cStr = [str
UTF8String];

unsigned char result[16];

CC_MD5( cStr, (uint32_t)strlen(cStr), result );

return [NSString
stringWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",

result[0], result[1], result[2], result[3],

result[4], result[5], result[6], result[7],

result[8], result[9], result[10], result[11],

result[12], result[13], result[14], result[15]

];

}

@end

#import <Foundation/Foundation.h>

#import <CommonCrypto/CommonDigest.h>

#import <UIKit/UIKit.h>

@interface CreateMD5WithFile : NSObject

+(NSString *)createMD5WithFile:(NSString *)string;

+(NSString*)fileMD5:(NSData *)data;

@end

#import "CreateMD5WithFile.h"

#import "Md5.h"

@implementation CreateMD5WithFile

+(NSString *)createMD5WithFile:(NSData *)imageData

{

NSString * string = [[NSString alloc] initWithData:imageData encoding:NSUTF8StringEncoding];

return [Md5 md5:string];

}

+(NSString*)fileMD5:(NSData *)data

{

NSString * dataPath = NSTemporaryDirectory();

//将图片归档

[data writeToFile:[dataPath stringByAppendingPathComponent:@"dataForImage.tmp"] atomically:YES];

//

NSFileHandle *handle = [NSFileHandle fileHandleForReadingAtPath:[dataPath stringByAppendingPathComponent:@"dataForImage.tmp"]];

if( handle== nil ) return @"ERROR
GETTING FILE MD5"; // file didn't exist

CC_MD5_CTX md5;

CC_MD5_Init(&md5);

BOOL done = NO;

while(!done)

{

NSData* fileData = [handle readDataOfLength: 1000 ];

CC_MD5_Update(&md5, [fileData bytes], [fileData length]);

if( [fileData length] == 0 ) done = YES;

}

unsigned char digest[CC_MD5_DIGEST_LENGTH];

CC_MD5_Final(digest, &md5);

NSString* s = [NSString stringWithFormat: @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",

digest[0], digest[1],

digest[2], digest[3],

digest[4], digest[5],

digest[6], digest[7],

digest[8], digest[9],

digest[10], digest[11],

digest[12], digest[13],

digest[14], digest[15]];

return s;

}

@end

---------------------------------使用-----------------------------------

//

// ViewController.m

// FXMD5

//

// Created by Floating_SH on 16/1/6.

// Copyright © 2016年 SH. All rights reserved.

//

#import "ViewController.h"

#import "Md5.h"

#import "CreateMD5WithFile.h"

#import "ReduceImageRatio.h"

@interface
ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

[super
viewDidLoad];

// 1.根据一个字符串生成一个md5码,

NSString *string1 =
@"http://baidu.com";

NSLog(@"%@",[Md5
md5:string1]);

// 23901b9dc3d84176eb001d386a96be9e
系统MD5

// 23901B9DC3D84176EB001D386A96BE9E
生成MD5

// 2.对一个文件求md5

UIImage *image = [UIImage
imageNamed:@"1"];

//
将图片变小

UIImage *image_xs = [ReduceImageRatio
imageWithMaxSide:200
sourceImage:image];

//
将图片写入沙盒

// (1)归档

NSData *data =
UIImagePNGRepresentation(image_xs);

// (2)写入沙盒

NSString *DocumentPath =
NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES)[0];

NSString *filePath = [DocumentPath
stringByAppendingPathComponent:@"1.png"];

NSLog(@"%@",filePath);

[data writeToFile:filePath
atomically:YES];

//
对图片求md5

NSLog(@"%@",[CreateMD5WithFile
fileMD5:data]);

}

- (void)didReceiveMemoryWarning {

[super
didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end