【转】IOS 学习之 NSPredicate 模糊、精确、查询

2022-07-17 12:17:31

转自：http://blog.csdn.net/lianbaixue/article/details/10579117

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。

定义(最常用到的方法)：

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

Format：
(1)比较运算符>,<,==,>=,<=,!=
可用于数值及字符串
例：@"number > 100"

(2)范围运算符：IN、BETWEEN
例：@"number BETWEEN {1,5}"
@"address IN {‘shanghai‘,‘beijing‘}"

(3)字符串本身:SELF
例：@“SELF == ‘APPLE’"

(4)字符串相关：BEGINSWITH、ENDSWITH、CONTAINS
例：@"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
例：@"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

例：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];

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【转】IOS 学习之 NSPredicate 模糊、精确、查询

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