【轉】 iOS 學習之 NSPredicate 模糊、精確、查詢

時間 2019-11-07

原文原文鏈接

簡述：Cocoa框架中的NSPredicate用於查詢，原理和用法都相似於SQL中的where，做用至關於數據庫的過濾取。

定義(最經常使用到的方法)：html

1 NSPredicate *ca = [NSPredicate predicateWithFormat:(NSString *), ...]; 正則表達式

(1)比較運算符>,<,==,>=,<=,!=
可用於數值及字符串
例：@"number > 100"

(2)範圍運算符：IN、BETWEEN
例：@"number BETWEEN {1,5}"
@"address IN {'shanghai','beijing'}"

(3)字符串自己:SELF
例：@「SELF == ‘APPLE’"

(4)字符串相關：BEGINSWITH、ENDSWITH、CONTAINS
例：@"name CONTAIN[cd] 'ang'" //包含某個字符串
@"name BEGINSWITH[c] 'sh'" //以某個字符串開頭
@"name ENDSWITH[d] 'ang'" //以某個字符串結束
注:[c]不區分大小寫[d]不區分發音符號即沒有重音符號[cd]既不區分大小寫，也不區分發音符號。

(5)通配符：LIKE
例：@"name LIKE[cd] '*er*'" //*表明通配符,Like也接受[cd].
@"name LIKE[cd] '???er*'"

(6)正則表達式：MATCHES
例：NSString *regex = @"^A.+e$"; //以A開頭，e結尾
@"name MATCHES %@",regex數據庫

實際應用：
(1)對NSArray進行過濾框架

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

(2)判斷字符串首字母是否爲字母:

1  
2 NSString *regex = @"[A-Za-z]+";    
3 NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];    
4     
5 if ([predicate evaluateWithObject:aString]) {    
6 }

(3)字符串替換：

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

(4)截取字符串以下：函數

 1 //組裝一個字符串，須要把裏面的網址解析出來    
 2 NSString *urlString=@"<meta/><link/><title>1Q84 BOOK1</title></head><body>";    
 3     
 4 //NSRegularExpression類裏面調用表達的方法須要傳遞一個NSError的參數。下面定義一個      
 5 NSError *error;    
 6     
 7 //http+:[^\\s]* 這個表達式是檢測一個網址的。(?<=title\>).*(?=</title)截取html文章中的<title></title>中內文字的正則表達式    
 8 NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(?<=title\\>).*(?=</title)" options:0 error:&error];    
 9     
10 if (regex != nil) {    
11     NSTextCheckingResult *firstMatch=[regex firstMatchInString:urlString options:0 range:NSMakeRange(0, [urlString length])];    
12         
13     if (firstMatch) {    
14         NSRange resultRange = [firstMatch rangeAtIndex:0];    
15             
16         //從urlString當中截取數據    
17         NSString *result=[urlString substringWithRange:resultRange];    
18         //輸出結果    
19         NSLog(@"->%@<-",result);    
20     }    
21         
22 }

(5)判斷手機號碼，電話號碼函數 fetch

 1 // 正則判斷手機號碼地址格式  
 2 - (BOOL)isMobileNumber:(NSString *)mobileNum  
 3 {  
 4        /** 
 5         * 手機號碼 
 6         * 移動：134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188 
 7         * 聯通：130,131,132,152,155,156,185,186 
 8         * 電信：133,1349,153,180,189 
 9         */  
10        NSString * MOBILE = @"^1(3[0-9]|5[0-35-9]|8[025-9])\\d{8}$";  
11        /** 
12         10         * 中國移動：China Mobile 
13         11         * 134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188 
14         12         */  
15        NSString * CM = @"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])\\d)\\d{7}$";  
16        /** 
17         15         * 中國聯通：China Unicom 
18         16         * 130,131,132,152,155,156,185,186 
19         17         */  
20        NSString * CU = @"^1(3[0-2]|5[256]|8[56])\\d{8}$";  
21        /** 
22         20         * 中國電信：China Telecom 
23         21         * 133,1349,153,180,189 
24         22         */  
25        NSString * CT = @"^1((33|53|8[09])[0-9]|349)\\d{7}$";  
26        /** 
27         25         * 大陸地區固話及小靈通 
28         26         * 區號：010,020,021,022,023,024,025,027,028,029 
29         27         * 號碼：七位或八位 
30         28         */  
31       // NSString * PHS = @"^0(10|2[0-5789]|\\d{3})\\d{7,8}$";  
32       
33      NSPredicate *regextestmobile = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", MOBILE];  
34      NSPredicate *regextestcm = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CM];  
35      NSPredicate *regextestcu = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CU];  
36      NSPredicate *regextestct = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CT];  
37       
38     if (([regextestmobile evaluateWithObject:mobileNum] == YES)  
39     || ([regextestcm evaluateWithObject:mobileNum] == YES)  
40     || ([regextestct evaluateWithObject:mobileNum] == YES)  
41     || ([regextestcu evaluateWithObject:mobileNum] == YES))  
42     {  
43         if([regextestcm evaluateWithObject:mobileNum] == YES) {  
44           NSLog(@"China Mobile");  
45         } else if([regextestct evaluateWithObject:mobileNum] == YES) {  
46           NSLog(@"China Telecom");  
47         } else if ([regextestcu evaluateWithObject:mobileNum] == YES) {  
48           NSLog(@"China Unicom");  
49         } else {  
50           NSLog(@"Unknow");  
51         }  
52           
53         return YES;  
54     }  
55     else   
56     {  
57         return NO;  
58     }  
59 }

(6)郵箱驗證、電話號碼驗證:lua

 1 //是不是有效的正則表達式  
 2   
 3 +(BOOL)isValidateRegularExpression:(NSString *)strDestination byExpression:(NSString *)strExpression  
 4   
 5 {  
 6   
 7    NSPredicate *predicate = [NSPredicatepredicateWithFormat:@"SELF MATCHES %@", strExpression];    
 8   
 9    return [predicate evaluateWithObject:strDestination];  
10   
11 }  
12   
13 //驗證email  
14 +(BOOL)isValidateEmail:(NSString *)email {  
15   
16    NSString *strRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{1,5}";  
17   
18    BOOL rt = [CommonTools isValidateRegularExpression:email byExpression:strRegex];  
19   
20    return rt;  
21   
22 }  
23   
24 //驗證電話號碼  
25 +(BOOL)isValidateTelNumber:(NSString *)number {  
26   
27    NSString *strRegex = @"[0-9]{1,20}";  
28   
29    BOOL rt = [CommonTools isValidateRegularExpression:number byExpression:strRegex];  
30   
31    return rt;  
32   
33 }

(7)NSDate進行篩選

 1 //日期在十天以內:  
 2 NSDate *endDate = [[NSDate date] retain];  
 3 NSTimeInterval timeInterval= [endDate timeIntervalSinceReferenceDate];  
 4 timeInterval -=3600*24*10;  
 5 NSDate *beginDate = [[NSDate dateWithTimeIntervalSinceReferenceDate:timeInterval] retain];  
 6 //對coredata進行篩選(假設有fetchRequest)  
 7 NSPredicate *predicate_date =  
 8 [NSPredicate predicateWithFormat:@"date >= %@ AND date <= %@", beginDate,endDate];  
 9       
10 [fetchRequest setPredicate:predicate_date];  
11 //釋放retained的對象  
12 [endDate release];  
13 [beginDate release];