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NSPredicate 谓词

时间:2016-05-24 21:02:06      阅读:213      评论:0      收藏:0      [点我收藏+]

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NSPredicate

简述:Cocoa框架中的NSPredicate用于查询,原理和用法都类似于SQL中的where,作用相当于数据库的过滤取。

//谓词
NSPredicate *ca = [NSPredicate predicateWithFormat:(NSString *), ...];

Format:

  • (1)比较运算符 >,<,==,>=,<=,!= 可用于数值及字符串

    @"number > 100"
    
  • (2)范围运算符:IN、BETWEEN

      @"number BETWEEN {1,5}" 
      @"address IN {‘shanghai‘,‘beijing‘}"
    
  • (3)字符串本身:SELF

    @“SELF == ‘APPLE’"

  • (4)字符串相关:BEGINSWITH、ENDSWITH、CONTAINS

    @"name CONTAIN[cd] ‘ang‘"       //包含某个字符串
    @"name BEGINSWITH[c] ‘sh‘"      //以某个字符串开头
    @"name ENDSWITH[d] ‘ang‘"       //以某个字符串结束
    注:[c]不区分大小写[d]不区分发音符号即没有重音符号[cd]既不区分大小写,也不区分发音符号。
    
  • (5)通配符:LIKE

    @"name LIKE[cd] ‘*er*‘"    //*代表通配符,Like也接受[cd].
    @"name LIKE[cd] ‘???er*‘"
    
  • (6)正则表达式:MATCHES

    NSString *regex = @"^A.+e$";   //以A开头,e结尾
    @"name MATCHES %@",regex
    

实际应用:

(1)对NSArray进行过滤

NSArray *array = [[NSArray alloc]initWithObjects:@"beijing",@"shanghai",@"guangzou",@"wuhan", nil];    
NSString *string = @"ang";    
NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF CONTAINS %@",string];    
NSLog(@"%@",[array filteredArrayUsingPredicate:pred]);    

(2)判断字符串首字母是否为字母:

NSString *regex = @"[A-Za-z]+";    
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];    

if ([predicate evaluateWithObject:aString]) {    
} 

(3)字符串替换:

NSError* error = NULL;    
NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:@"(encoding=\")[^\"]+(\")"    
                                                                            options:0    
                                                                            error:&error];    
NSString* sample = @"<xml encoding=\"abc\"></xml><xml encoding=\"def\"></xml><xml encoding=\"ttt\"></xml>";    
NSLog(@"Start:%@",sample);    
NSString* result = [regex stringByReplacingMatchesInString:sample    
                                                      options:0    
                                                       range:NSMakeRange(0, sample.length)    
                                                      withTemplate:@"$1utf-8$2"];    
NSLog(@"Result:%@", result);    

(4)截取字符串如下:

//组装一个字符串,需要把里面的网址解析出来    
NSString *urlString=@"<meta/><link/><title>1Q84 BOOK1</title></head><body>";    

//NSRegularExpression类里面调用表达的方法需要传递一个NSError的参数。下面定义一个      
NSError *error;    

//http+:[^\\s]* 这个表达式是检测一个网址的。(?<=title\>).*(?=</title)截取html文章中的<title></title>中内文字的正则表达式    
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(?<=title\\>).*(?=</title)" options:0 error:&error];    

if (regex != nil) {    
    NSTextCheckingResult *firstMatch=[regex firstMatchInString:urlString options:0 range:NSMakeRange(0, [urlString length])];    

    if (firstMatch) {    
        NSRange resultRange = [firstMatch rangeAtIndex:0];    

        //从urlString当中截取数据    
        NSString *result=[urlString substringWithRange:resultRange];    
        //输出结果    
        NSLog(@"->%@<-",result);    
    }    

} 

(5)判断手机号码,电话号码函数

// 正则判断手机号码地址格式  
- (BOOL)isMobileNumber:(NSString *)mobileNum  
{  
       /** 
        * 手机号码 
        * 移动:134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188 
        * 联通:130,131,132,152,155,156,185,186 
        * 电信:133,1349,153,180,189 
        */  
       NSString * MOBILE = @"^1(3[0-9]|5[0-35-9]|8[025-9])\\d{8}$";  
       /** 
        10         * 中国移动:China Mobile 
        11         * 134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188 
        12         */  
       NSString * CM = @"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])\\d)\\d{7}$";  
       /** 
        15         * 中国联通:China Unicom 
        16         * 130,131,132,152,155,156,185,186 
        17         */  
       NSString * CU = @"^1(3[0-2]|5[256]|8[56])\\d{8}$";  
       /** 
        20         * 中国电信:China Telecom 
        21         * 133,1349,153,180,189 
        22         */  
       NSString * CT = @"^1((33|53|8[09])[0-9]|349)\\d{7}$";  
       /** 
        25         * 大陆地区固话及小灵通 
        26         * 区号:010,020,021,022,023,024,025,027,028,029 
        27         * 号码:七位或八位 
        28         */  
      // NSString * PHS = @"^0(10|2[0-5789]|\\d{3})\\d{7,8}$";  

     NSPredicate *regextestmobile = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", MOBILE];  
     NSPredicate *regextestcm = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CM];  
     NSPredicate *regextestcu = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CU];  
     NSPredicate *regextestct = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CT];  

    if (([regextestmobile evaluateWithObject:mobileNum] == YES)  
    || ([regextestcm evaluateWithObject:mobileNum] == YES)  
    || ([regextestct evaluateWithObject:mobileNum] == YES)  
    || ([regextestcu evaluateWithObject:mobileNum] == YES))  
    {  
        if([regextestcm evaluateWithObject:mobileNum] == YES) {  
          NSLog(@"China Mobile");  
        } else if([regextestct evaluateWithObject:mobileNum] == YES) {  
          NSLog(@"China Telecom");  
        } else if ([regextestcu evaluateWithObject:mobileNum] == YES) {  
          NSLog(@"China Unicom");  
        } else {  
          NSLog(@"Unknow");  
        }  

        return YES;  
    }  
    else   
    {  
        return NO;  
    }  
} 

(6)邮箱验证、电话号码验证:

//是否是有效的正则表达式  

+(BOOL)isValidateRegularExpression:(NSString *)strDestination byExpression:(NSString *)strExpression  

{  

   NSPredicate *predicate = [NSPredicatepredicateWithFormat:@"SELF MATCHES %@", strExpression];    

   return [predicate evaluateWithObject:strDestination];  

}  

//验证email  
+(BOOL)isValidateEmail:(NSString *)email {  

   NSString *strRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{1,5}";  

   BOOL rt = [CommonTools isValidateRegularExpression:email byExpression:strRegex];  

   return rt;  

}  

//验证电话号码  
+(BOOL)isValidateTelNumber:(NSString *)number {  

   NSString *strRegex = @"[0-9]{1,20}";  

   BOOL rt = [CommonTools isValidateRegularExpression:number byExpression:strRegex];  

   return rt;  

} 

(7)NSDate进行筛选

//日期在十天之内:  
NSDate *endDate = [[NSDate date] retain];  
NSTimeInterval timeInterval= [endDate timeIntervalSinceReferenceDate];  
timeInterval -=3600*24*10;  
NSDate *beginDate = [[NSDate dateWithTimeIntervalSinceReferenceDate:timeInterval] retain];  
//对coredata进行筛选(假设有fetchRequest)  
NSPredicate *predicate_date =  
[NSPredicate predicateWithFormat:@"date >= %@ AND date <= %@", beginDate,endDate];  

[fetchRequest setPredicate:predicate_date];  
//释放retained的对象  
[endDate release];  
[beginDate release];  

NSPredicate 谓词

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原文地址:http://www.cnblogs.com/kinghx/p/5524632.html

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