加密 续

终于把iOS平台下的加密算法调通了，在这里记录一下,并说一下遇到的N种加密问题。

首先要说明一下我所遇到的需要加密的数据：向服务器端发送用户名与密码进行portal认证，当然为了显示出专业性（扯淡的说），服务器提供商要求发送经过四层加密后的数据，分别是：
1、用户名、密码分别用Base64加密

2、用户名，密码和发送时间相加之后进行DES加密

3、对加密后的结果再进行一次Base64加密

4、最后把结果用RLENCODE 转化成UTF-8

这其中主要使用到Base64加密与DES加密，再就是数据转换，过程如下：

//分别对用户及密码进行Base64加密

NSString *BASE64userName = [GTMBase64 base64Encode:[Puser.username  dataUsingEncoding: NSUTF8StringEncoding]];

NSString *BASE64password = [GTMBase64 base64Encode:[Puser.password  dataUsingEncoding: NSUTF8StringEncoding]];

//串联用户及密码字符串

NSString *allStr = [NSString stringWithFormat:@"username=%@,password=%@,timestamp=%@",BASE64userName,BASE64password,[Util getCurrentDateTime]];

Airsource_Log_Debug(@”allStr = %@”,allStr);

//DES加密

NSData *allStrData = [allStr dataUsingEncoding: NSUTF8StringEncoding];

NSData *DESData = [EncryptUtil DESEncrypt:allStrData WithKey:Post_SHAREKEY];

//Base64加密

NSString *Base64DESStr = [GTMBase64 base64Encode:DESData];

//Airsource_Log_Debug(@”Base64DESStr = %@”,Base64DESStr);

//URLENCODE 转化成UTF-8

NSString *URLENCODEBase64DESStr = [Base64DESStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

//Airsource_Log_Debug(@”URLENCODEBase64DESStr = %@”,URLENCODEBase64DESStr);

//串联加密后的所有字符串

NSString *ipStr = [localIPAddress localIPAddress];//获取本地IP

Airsource_Log_Debug(@”ipStr = %@”,ipStr );

strurl = [NSString stringWithFormat:@"%@%@%@&userip=%@&userPublicIp=%@&language=Chinese",strurl,userInfo,URLENCODEBase64DESStr,ipStr,ipStr];

Airsource_Log_Debug(@”strurl = %@”,strurl );

终于得到了最后需要发送的加密string了。

其中用到的加密方法：GTMBase64

#import “GTMBase64.h”
static const char *kBase64EncodeChars = “ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/”;
static const char *kWebSafeBase64EncodeChars = “ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_”;
static const char kBase64PaddingChar = ‘=’;
static const char kBase64InvalidChar = 99;

@interface GTMBase64 (PrivateMethods)

+(NSData *)baseEncode:(const void *)bytes
length:(NSUInteger)length
charset:(const char *)charset
padded:(BOOL)padded;

@end

@implementation GTMBase64

//解密：
+ (NSData*) base64Decode:(NSString *)string
{
unsigned long ixtext, lentext;
unsigned char ch, inbuf[4], outbuf[4];
short i, ixinbuf;
Boolean flignore, flendtext = false;
const unsigned char *tempcstring;
NSMutableData *theData;

if (string == nil) {
return [NSData data];
}

ixtext = 0;

tempcstring = (const unsigned char *)[string UTF8String];

lentext = [string length];

theData = [NSMutableData dataWithCapacity: lentext];

ixinbuf = 0;

while (true) {
if (ixtext >= lentext){
break;
}

ch = tempcstring [ixtext++];

flignore = false;

if ((ch >= ‘A’) && (ch = ‘a’) && (ch = ’0′) && (ch ch = ch – ’0′ + 52;
} else if (ch == ‘+’) {
ch = 62;
} else if (ch == ‘=’) {
flendtext = true;
} else if (ch == ‘/’) {
ch = 63;
} else {
flignore = true;
}

if (!flignore) {
short ctcharsinbuf = 3;
Boolean flbreak = false;

if (flendtext) {
if (ixinbuf == 0) {
break;
}

if ((ixinbuf == 1) || (ixinbuf == 2)) {
ctcharsinbuf = 1;
} else {
ctcharsinbuf = 2;
}

ixinbuf = 3;

flbreak = true;
}

inbuf [ixinbuf++] = ch;

if (ixinbuf == 4) {
ixinbuf = 0;

outbuf[0] = (inbuf[0] << 2) | ((inbuf[1] & 0×30) >> 4);
outbuf[1] = ((inbuf[1] & 0x0F) << 4) | ((inbuf[2] & 0x3C) >> 2);
outbuf[2] = ((inbuf[2] & 0×03) << 6) | (inbuf[3] & 0x3F);

for (i = 0; i < ctcharsinbuf; i++) {
[theData appendBytes: &outbuf[i] length: 1];
}
}

if (flbreak) {
break;
}
}
}

return theData;
}
//加密：
+ (NSString*) base64Encode:(NSData *)data
{
static char base64EncodingTable[64] = {
‘A’, ‘B’, ‘C’, ‘D’, ‘E’, ‘F’, ‘G’, ‘H’, ‘I’, ‘J’, ‘K’, ‘L’, ‘M’, ‘N’, ‘O’, ‘P’,
‘Q’, ‘R’, ‘S’, ‘T’, ‘U’, ‘V’, ‘W’, ‘X’, ‘Y’, ‘Z’, ‘a’, ‘b’, ‘c’, ‘d’, ‘e’, ‘f’,
‘g’, ‘h’, ‘i’, ‘j’, ‘k’, ‘l’, ‘m’, ‘n’, ‘o’, ‘p’, ‘q’, ‘r’, ‘s’, ‘t’, ‘u’, ‘v’,
‘w’, ‘x’, ‘y’, ‘z’, ’0′, ’1′, ’2′, ’3′, ’4′, ’5′, ’6′, ’7′, ’8′, ’9′, ‘+’, ‘/’
};
int length = [data length];
unsigned long ixtext, lentext;
long ctremaining;
unsigned char input[3], output[4];
short i, charsonline = 0, ctcopy;
const unsigned char *raw;
NSMutableString *result;

lentext = [data length];
if (lentext < 1)
return @”";
result = [NSMutableString stringWithCapacity: lentext];
raw = [data bytes];
ixtext = 0;

while (true) {
ctremaining = lentext – ixtext;
if (ctremaining break;
for (i = 0; i < 3; i++) {
unsigned long ix = ixtext + i;
if (ix < lentext) input[i] = raw[ix]; else input[i] = 0; } output[0] = (input[0] & 0xFC) >> 2;
output[1] = ((input[0] & 0×03) << 4) | ((input[1] & 0xF0) >> 4);
output[2] = ((input[1] & 0x0F) << 2) | ((input[2] & 0xC0) >> 6);
output[3] = input[2] & 0x3F;
ctcopy = 4;
switch (ctremaining) {
case 1:
ctcopy = 2;
break;
case 2:
ctcopy = 3;
break;
}

for (i = 0; i < ctcopy; i++)
[result appendString: [NSString stringWithFormat: @"%c", base64EncodingTable[output[i]]]];

for (i = ctcopy; i < 4; i++) [result appendString: @"="]; ixtext += 3; charsonline += 4; if ((length > 0) && (charsonline >= length))
charsonline = 0;
}
return result;
}

@end

用到的加密方法：EncryptUtil（DES加密）

#import “EncryptUtil.h”
#import “CommonCrypto/CommonCryptor.h”
#import “GTMBase64.h”

@implementation EncryptUtil

//DES加密
+ (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
{
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));

[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

NSUInteger dataLength = [data length];

size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);

size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr, kCCBlockSizeDES,
NULL,
[data bytes], dataLength,
buffer, bufferSize,
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}

free(buffer);
return nil;
}
//DES解密
+ (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key
{
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));

[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

NSUInteger dataLength = [data length];

size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);

size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr, kCCBlockSizeDES,
NULL,
[data bytes], dataLength,
buffer, bufferSize,
&numBytesDecrypted);

if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}

free(buffer);
return nil;
}
@end

获取IP地址

+ (NSString *)localIPAddress
{
NSString *localIP = nil;
struct ifaddrs *addrs;
if (getifaddrs(&addrs)==0) {
const struct ifaddrs *cursor = addrs;
while (cursor != NULL) {
if (cursor->ifa_addr->sa_family == AF_INET && (cursor->ifa_flags & IFF_LOOPBACK) == 0)
{
//NSString *name = [NSString stringWithUTF8String:cursor->ifa_name];
//if ([name isEqualToString:@"en0"]) // Wi-Fi adapter
{
localIP = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)cursor->ifa_addr)->sin_addr)];
break;
}
}
cursor = cursor->ifa_next;
}
freeifaddrs(addrs);
}
return localIP;
}

iOS base64加密解密

• |
• 浏览：2901
• |
• 更新：2013-05-17 12:12

• 从参考资料的地址中下载GTMBase64.zip库文件包，并解压，获得GTMBase64.h,GTMBase64.m和GTMDefines.h三个文件。

• 将解压得到的三个文件，添加到项目中。

• 新建一个base64的类，在base64.h中天假四个函数：

  + (NSString*)encodeBase64String:(NSString*)input;

  + (NSString*)decodeBase64String:(NSString*)input;

  + (NSString*)encodeBase64Data:(NSData*)data;

  + (NSString*)decodeBase64Data:(NSData*)data;

  在base64.m文件中，实现上面4个函数：

  + (NSString*)encodeBase64String:(NSString* )input {

  NSData*data = [inputdataUsingEncoding:NSUTF8StringEncodingallowLossyConversion:YES];

      data = [GTMBase64encodeData:data];

  NSString*base64String = [[NSStringalloc]initWithData:dataencoding:NSUTF8StringEncoding] ;

  returnbase64String;

  }

  + (NSString*)decodeBase64String:(NSString* )input {

  NSData*data = [inputdataUsingEncoding:NSUTF8StringEncodingallowLossyConversion:YES];

      data = [GTMBase64decodeData:data];

  NSString*base64String = [[NSStringalloc]initWithData:dataencoding:NSUTF8StringEncoding] ;

  returnbase64String;

  }

  + (NSString*)encodeBase64Data:(NSData*)data {

      data = [GTMBase64encodeData:data];

  NSString*base64String = [[NSStringalloc]initWithData:dataencoding:NSUTF8StringEncoding] ;

  returnbase64String;

  }

  + (NSString*)decodeBase64Data:(NSData*)data {

      data = [GTMBase64decodeData:data];

  NSString*base64String = [[NSStringalloc]initWithData:dataencoding:NSUTF8StringEncoding] ;

  returnbase64String;

  }

• 直接调用+ (NSString*)encodeBase64String:(NSString* )input和

  + (NSString*)decodeBase64String:(NSString* )input就可以进行加解密。

• 可以从参考资料的地址中下载dem

[iOS]AES加密在iOS上面的实现 

Encryption.h文件

[plain] view plaincopy

1. //  
2. //  Encryption.h  
3. //  DownloadFile  
4. //  
5. //  Created by zhoumin on 12-1-16.  
6. //  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.  
7. //  
8.   
9. #import <Foundation/Foundation.h>  
10.   
11. @class NSString;  
12.   
13. @interface NSData (Encryption)  
14.   
15. - (NSData *)AES256EncryptWithKey:(NSString *)key;   //加密  
16. - (NSData *)AES256DecryptWithKey:(NSString *)key;   //解密  
17. - (NSString *)newStringInBase64FromData;            //追加64编码  
18. + (NSString*)base64encode:(NSString*)str;           //同上64编码  
19.   
20. @end  

Encryption.m文件

[plain] view plaincopy

1. //  
2. //  Encryption.m  
3. //  DownloadFile  
4. //  
5. //  Created by  on 12-1-16.  
6. //  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.  
7. //  
8.   
9. #import "Encryption.h"  
10. #import <CommonCrypto/CommonCryptor.h>  
11.   
12.   
13. static char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";  
14.   
15. @implementation NSData (Encryption)  
16.   
17. - (NSData *)AES256EncryptWithKey:(NSString *)key   //加密  
18. {  
19.     char keyPtr[kCCKeySizeAES256+1];  
20.     bzero(keyPtr, sizeof(keyPtr));  
21.     [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];  
22.     NSUInteger dataLength = [self length];  
23.     size_t bufferSize = dataLength + kCCBlockSizeAES128;  
24.     void *buffer = malloc(bufferSize);  
25.     size_t numBytesEncrypted = 0;  
26.     CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,  
27.                                           kCCOptionPKCS7Padding | kCCOptionECBMode,  
28.                                           keyPtr, kCCBlockSizeAES128,  
29.                                           NULL,  
30.                                           [self bytes], dataLength,  
31.                                           buffer, bufferSize,  
32.                                           &numBytesEncrypted);  
33.     if (cryptStatus == kCCSuccess) {  
34.         return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];  
35.     }  
36.     free(buffer);  
37.     return nil;  
38. }  
39.   
40.   
41. - (NSData *)AES256DecryptWithKey:(NSString *)key   //解密  
42. {  
43.     char keyPtr[kCCKeySizeAES256+1];  
44.     bzero(keyPtr, sizeof(keyPtr));  
45.     [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];  
46.     NSUInteger dataLength = [self length];  
47.     size_t bufferSize = dataLength + kCCBlockSizeAES128;  
48.     void *buffer = malloc(bufferSize);  
49.     size_t numBytesDecrypted = 0;  
50.     CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,  
51.                                           kCCOptionPKCS7Padding | kCCOptionECBMode,  
52.                                           keyPtr, kCCBlockSizeAES128,  
53.                                           NULL,  
54.                                           [self bytes], dataLength,  
55.                                           buffer, bufferSize,  
56.                                           &numBytesDecrypted);  
57.     if (cryptStatus == kCCSuccess) {  
58.         return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];  
59.     }  
60.     free(buffer);  
61.     return nil;  
62. }  
63.   
64.   
65. - (NSString *)newStringInBase64FromData            //追加64编码  
66. {  
67.     NSMutableString *dest = [[NSMutableString alloc] initWithString:@""];  
68.     unsigned char * working = (unsigned char *)[self bytes];  
69.     int srcLen = [self length];  
70.     for (int i=0; i<srcLen; i += 3) {  
71.         for (int nib=0; nib<4; nib++) {  
72.             int byt = (nib == 0)?0:nib-1;  
73.             int ix = (nib+1)*2;  
74.             if (i+byt >= srcLen) break;  
75.             unsigned char curr = ((working[i+byt] << (8-ix)) & 0x3F);  
76.             if (i+nib < srcLen) curr |= ((working[i+nib] >> ix) & 0x3F);  
77.             [dest appendFormat:@"%c", base64[curr]];  
78.         }  
79.     }  
80.     return dest;  
81. }  
82.   
83. + (NSString*)base64encode:(NSString*)str  
84. {  
85.     if ([str length] == 0)  
86.         return @"";  
87.     const char *source = [str UTF8String];  
88.     int strlength  = strlen(source);  
89.     char *characters = malloc(((strlength + 2) / 3) * 4);  
90.     if (characters == NULL)  
91.         return nil;  
92.     NSUInteger length = 0;  
93.     NSUInteger i = 0;  
94.     while (i < strlength) {  
95.         char buffer[3] = {0,0,0};  
96.         short bufferLength = 0;  
97.         while (bufferLength < 3 && i < strlength)  
98.             buffer[bufferLength++] = source[i++];  
99.         characters[length++] = base64[(buffer[0] & 0xFC) >> 2];  
100.         characters[length++] = base64[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];  
101.         if (bufferLength > 1)  
102.             characters[length++] = base64[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];  
103.         else characters[length++] = '=';  
104.         if (bufferLength > 2)  
105.             characters[length++] = base64[buffer[2] & 0x3F];  
106.         else characters[length++] = '=';  
107.     }  
108.     NSString *g = [[[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES] autorelease];  
109.     return g;  
110. }  
111.   
112.   
113. @end  

测试

[cpp] view plaincopy

1. NSString *key = @"my password";    
2. NSString *secret = @"text to encrypt";    
3. //加密    
4. NSData *plain = [secret dataUsingEncoding:NSUTF8StringEncoding];    
5. NSData *cipher = [plain AES256EncryptWithKey:key];    
6. NSLog(@"%@",[[cipher newStringInBase64FromData] autorelease]);    
7. printf("%s\n", [[cipher description] UTF8String]);    
8. NSLog(@"%@", [[[NSString alloc] initWithData:cipher encoding:NSUTF8StringEncoding] autorelease]);//打印出null,这是因为没有解密。    
9. //解密    
10. plain = [cipher AES256DecryptWithKey:key];    
11. printf("%s\n", [[plain description] UTF8String]);    
12. NSLog(@"%@", [[[NSString alloc] initWithData:plain encoding:NSUTF8StringEncoding] autorelease]);    
13. //打印出secret的内容,用密码解密过了。如果使用错误的密码，则打印null    

demo下载：http://download.csdn.net/detail/z251257144/4820200

iOS代码加密常用加密方式

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• 浏览：85
• |
• 更新：2015-01-06 17:08
• |
• 标签： 加密 

iOS代码加密常用加密方式，常见的iOS代码加密常用加密方式算法包括MD5加密、AES加密、BASE64加密，三大算法iOS代码加密是如何进行加密的，且看下文

MD5 iOS代码加密

1. 1

   MD5 iOS代码加密

   创建MD5类，代码如下

   #import <Foundation/Foundation.h>

   @interface CJMD5 : NSObject

   +(NSString *)md5HexDigest:(NSString *)input;

   @end

2. 2

   #import "CJMD5.h"

   #import <CommonCrypto/CommonDigest.h>

   @implementation CJMD5

   +(NSString *)md5HexDigest:(NSString *)input{

       

       const char* str = [input UTF8String];

       unsigned char result[CC_MD5_DIGEST_LENGTH];

       CC_MD5(str, strlen(str), result);

       NSMutableString *ret = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH];

       

       for(int i = 0; i<CC_MD5_DIGEST_LENGTH; i++) {

           [ret appendFormat:@"%02X",result];

       }

       return ret;

   }

   @end

3. 3

   MD5是不可逆的只有加密没有解密，iOS代码加密使用方式如下

   NSString *userName = @"cerastes";

   NSString *password = @"hello Word";

   //   MD5加密

   NSString *md5 = [CJMD5 md5HexDigest:password];

   NSLog(@"%@",md5);

   END

AES加密iOS代码加密

1. 1

   AES加密iOS代码加密使用方法

   //  AES加密

       NSString *encryptedData = [AESCrypt encrypt:userName password:password];//加密

       NSString *message = [AESCrypt decrypt:encryptedData password:password]; //解密

       NSLog(@"加密结果 = %@",encryptedData);

       NSLog(@"解密结果 = %@",message);

   END

BASE64加密iOS代码加密

1. 1

   BASE64加密iOS代码加密添加如下方法

   .h

   + (NSString*)encodeBase64String:(NSString *)input;

   + (NSString*)decodeBase64String:(NSString *)input;

   + (NSString*)encodeBase64Data:(NSData *)data;

   + (NSString*)decodeBase64Data:(NSData *)data;

2. 2

   .m

   + (NSString*)encodeBase64String:(NSString * )input {

       NSData *data = [input dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];

       data = [GTMBase64 encodeData:data];

       NSString *base64String = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

       return base64String;

   }

   + (NSString*)decodeBase64String:(NSString * )input {

       NSData *data = [input dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];

       data = [GTMBase64 decodeData:data];

       NSString *base64String = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

       return base64String;

   }

   + (NSString*)encodeBase64Data:(NSData *)data {

       data = [GTMBase64 encodeData:data];

       NSString *base64String = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

       return base64String;

   }

   + (NSString*)decodeBase64Data:(NSData *)data {

       data = [GTMBase64 decodeData:data];

       NSString *base64String = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

       return base64String;

   }

3. 3

   BASE64加密iOS代码加密使用方法

   //    BASE64加密

       NSString *baseEncodeString = [GTMBase64 encodeBase64String:password];

       NSString *baseDecodeString = [GTMBase64 decodeBase64String:baseEncodeString];

       NSLog(@"baseEncodeString = %@",baseEncodeString);

       NSLog(@"baseDecodeString = %@",baseDecodeString);

   END

iOS应用代码加密

1. 除了以上的三种算法的iOS代码加密之外，iOS应用代码加密也是非常重要的，这里就不贴代码了，主要的iOS代码加密方式如下，iOS应用代码加密是 爱 加 密 平台提供的专业的iOS加密服务。

   
2. 2

   1）本地数据加密

   对NSUserDefaults，sqlite存储文件数据加密，保护帐号和关键信息。

   2）URL编码加密

   对程序中出现的URL进行编码加密，防止URL被静态分析

   3）网络传输数据加密

   对客户端传输数据提供加密方案，有效防止通过网络接口的拦截获取

   4）方法体，方法名高级混淆

   对应用程序的方法名和方法体进行混淆，保证源码被逆向后无法解析代码

   5）程序结构混排加密

   对应用程序逻辑结构进行打乱混排，保证源码可读性降到最低。

   
   

   IOS - CoreData 增删改查

   #pragma mark - Core Data Methods

   - (void)insertObjectWithFileName:(NSString *)fileName

   {

       /**

        SQL新增记录的过程

        1. 拼接一个INSERT的SQL语句

        2. 执行SQL

        */

       // 1. 实例化并让context“准备”将一条个人记录增加到数据库

       ReaderDocument *document = [NSEntityDescription insertNewObjectForEntityForName:kOAPDFDocument inManagedObjectContext:self.managedObjectContext];

       

       // 2. 设置个人信息

       document.fileName = fileName;

       

       // 3. 保存(让context保存当前的修改)

       if ([self.managedObjectContext save:nil]) {

           NSLog(@"新增成功");

       } else {

           NSLog(@"新增失败");

       }

   }

    

   - (NSMutableArray *)getObjectsWithPredicate:(NSString *)predicate

   {

       // 1. 实例化一个查询(Fetch)请求

       NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:kOAPDFDocument];

       

       // 3. 条件查询，通过谓词来实现的

       //    request.predicate = [NSPredicate predicateWithFormat:@"age < 60 && name LIKE '*五'"];

       // 在谓词中CONTAINS类似于数据库的 LIKE '%王%'

       //    request.predicate = [NSPredicate predicateWithFormat:@"phoneNo CONTAINS '1'"];

       // 如果要通过key path查询字段，需要使用%K

       //    request.predicate = [NSPredicate predicateWithFormat:@"%K CONTAINS '1'", @"phoneNo"];

       // 直接查询字表中的条件

       

       // 2. 让_context执行查询数据

       NSArray *array = [self.managedObjectContext executeFetchRequest:request error:nil];

       

   //    for (OAPDFDocument *pdf in array) {

   //        NSLog(@"\nfielName:%@ \nfilePath:%@ \nfileSize:%@", pdf.fileName, pdf.filePath, pdf.fileSize);

           

           // 在CoreData中，查询是懒加载的

           // 在CoreData本身的SQL查询中，是不使用JOIN的，不需要外键

           // 这种方式的优点是：内存占用相对较小，但是磁盘读写的频率会较高

   //        for (Book *b in p.books) {

   //            NSLog(@"%@ %@ %@", b.name, b.price, b.author);

   //        }

   //    }

       

       //    for (Book *b in array) {

       //        NSLog(@"%@ %@ %@", b.name, b.price, b.author);

       //    }

       return [NSMutableArray arrayWithArray:array];

   }

    

   - (void)editObjectsWithPredicate:(NSPredicate *)predicate withState:(NSNumber *)state

   {

       // 1. 实例化一个查询(Fetch)请求

       NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:kOAPDFDocument];

       

       // 2. 条件查询，通过谓词来实现的

       request.predicate = predicate;

       // 在谓词中CONTAINS类似于数据库的 LIKE '%王%'

       //    request.predicate = [NSPredicate predicateWithFormat:@"phoneNo CONTAINS '1'"];

       // 如果要通过key path查询字段，需要使用%K

       //    request.predicate = [NSPredicate predicateWithFormat:@"%K CONTAINS '1'", @"phoneNo"];

       // 直接查询字表中的条件

       

       // 3. 让_context执行查询数据

       NSArray *array = [self.managedObjectContext executeFetchRequest:request error:nil];

       for (ReaderDocument *pdf in array) {

           // 3.1修改公文阅读状态

           pdf.fileTag = state;

           

           // 3.2修改公文最新打开日期

           NSFileManager* fileMngr = [NSFileManager defaultManager];

           NSDictionary* attributes = [fileMngr attributesOfItemAtPath:pdf.fileURL error:nil];

           pdf.lastOpen = (NSDate *)[attributes objectForKey:NSFileModificationDate];

           

           // 3.3获取并保存，该文件的首页缩略图

           UIImage *thumbImage = [pdf imageFromPDFWithDocumentRef:pdf.fileURL];

           pdf.thumbImage = UIImagePNGRepresentation(thumbImage);

           

           [self.collectionView reloadData];

           break;

       }

       // 4. 通知_context修改数据是否成功

       if ([self.managedObjectContext save:nil]) {

           NSLog(@"修改成功");

       } else {

           NSLog(@"修改失败");

       }

   }

    

   - (void)removeObjectsWithPredicate:(NSString *)predicate

   {

       // 1. 实例化查询请求

       NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:kOAPDFDocument];

       

       // 2. 设置谓词条件

   //    request.predicate = [NSPredicate predicateWithFormat:@"name = '张老头'"];

       request.predicate = [NSPredicate predicateWithFormat:predicate];

       

       // 3. 由上下文查询数据

       NSArray *result = [self.managedObjectContext executeFetchRequest:request error:nil];

       

       // 4. 输出结果

       for (ReaderDocument *pdf in result) {

           // 删除一条记录

           [self.managedObjectContext deleteObject:pdf];

           

           BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:pdf.filePath];

           if (fileExists) {

               [self removeFileWithName:pdf.fileName];

           }else{

               NSLog(@"File:%@ is not exist!",pdf.fileName);

           }

   //        break;

       }

       

       // 5. 通知_context保存数据

       if ([self.managedObjectContext save:nil]) {

           NSLog(@"删除%lu文件成功",(unsigned long)[result count]);

       } else {

           NSLog(@"删除失败");

       }

   }

    

   - (void)removeFileWithName:(NSString *)fileName

   {

       NSFileManager *fileManager = [NSFileManager defaultManager];

       NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];

       

       NSString *filePath = [documentsPath stringByAppendingPathComponent:fileName];

       NSError *error;

       BOOL success = [fileManager removeItemAtPath:filePath error:&error];

       if (success) {

           NSLog(@"Remove fiel:%@ Success!",fileName);

       }

       else

       {

           NSLog(@"Could not delete file -:%@ ",[error localizedDescription]);

       }

   }