NSPredicate 不适用于 ios 中的过滤

Posted 2023-03-04

【中文标题】NSPredicate 不适用于 ios 中的过滤

【英文标题】：NSPredicate is not working for Filtering in ios

【发布时间】：2015-07-20 13:57:33

【问题描述】：

我已尝试通过 NSPredicate 进行过滤。它在 NSMutableArray 中不起作用，但我在 Array 中尝试过，它工作正常。

使用数组的工作代码：

filterArray=[NSMutableArray arrayWithObjects:@"Yvan",@"Balu",@"Srinath",@"Aswin",@"Ram", nil];
NSPredicate *bPredicate =[NSPredicate predicateWithFormat:@"SELF beginswith[c] 'r'"];
NSArray *resultAr = [resultArray filteredArrayUsingPredicate:bPredicate];
NSLog(@"Output %@",resultAr);

正确产生：

Output (
Srinath,
Ram
)

我尝试使用包含字典数据的 NSMutableArray，但它不起作用。

结果数组的框架是：

for(int i=0;i<[priceArray count];i++)
    
        cellDict=[[NSMutableDictionary alloc]init];
        NSString *nameStr=nameArray[i];
        [cellDict setObject:nameStr forKey:@"Name"];
        [cellDict setObject:@([splPriceArray[i] intValue]) forKey:@"Percentage"];
        [cellDict setObject:@([priceArray[i] intValue]) forKey:@"Price"];
        [resultArray addObject:cellDict];
    

结果数组：

(
        
        Name = "Black Eyed Peas";
        Percentage = 0;
        Price = 80;
    ,
        
        Name = "Black Gram";
        Percentage = 0;
        Price = 56;
    ,
        
        Name = "Channa White";
        Percentage = 0;
        Price = 100;
    ,
        
        Name = "Double Beans";
        Percentage = 0;
        Price = 95;
    ,
        
        Name = "Gram Dall";
        Percentage = 0;
        Price = 100;
    ,
        
        Name = "Green Moong Dal";
        Percentage = 0;
        Price = 150;
    ,
        
        Name = "Ground Nut";
        Percentage = 0;
        Price = 140;
    ,
        
        Name = "Moong Dal";
        Percentage = 0;
        Price = 75;
    ,
        
        Name = "Orid Dal";
        Percentage = 0;
        Price = 100;
    ,
        
        Name = "Toor Dal";
        Percentage = 0;
        Price = 150;
    
) 

尝试过的谓词是：

//  NSPredicate *predit=[NSPredicate predicateWithFormat:@"Price contains[c] '100'"];

NSPredicate *pred=[NSPredicate predicateWithFormat:@"(Price == %@) AND (Percentage == %@)", @"100",@"0"];

NSArray *resultAr = [resultArray filteredArrayUsingPredicate:predit];

以上是正确的方法还是有更好的方法来实现它以获得：

expected output:
(
            
            Name = "Channa White";
            Percentage = 0;
            Price = 100;
        ,
            
            Name = "Gram Dall";
            Percentage = 0;
            Price = 100;
        ,          
            
            Name = "Orid Dal";
            Percentage = 0;
            Price = 100;
        
) 

【参考方案1】：

应该是Price而不是price，应该是Percentage而不是percentage 我猜Percentage 是NSNumber 的类型

我测试

    NSDictionary * dic1 = @
                        @"Name" : @"Black Eyed Peas",
                        @"Percentage":@(0),
                        @"Price" : @(80),
                        ;
    NSDictionary * dic2 = @
                        @"Name" : @"Black Eyed Peas",
                        @"Percentage":@(0),
                        @"Price" : @(100),
                        ;
    NSMutableArray * mutableArray = [[NSMutableArray alloc] initWithArray:@[dic1,dic2]];
    NSPredicate *pred= [NSPredicate predicateWithFormat:@"(Price == %@) AND (Percentage == %@)", @(100),@(0)];

    NSArray *resultAr = [mutableArray filteredArrayUsingPredicate:pred];
    NSLog(@"%@",resultAr);

日志

2015-07-20 22:11:44.535 OCTest[2192:79846] (
    
    Name = "Black Eyed Peas";
    Percentage = 0;
    Price = 100;

)

【讨论】：

对不起，我尝试了不同的方法，但 'p' 仅是 'P'，我更新了我的问题框架结果数组，但我该如何实现你的答案

注意，在我的代码中，是@(100)，即NSNumber，而不是@"100"

感谢它现在工作，我将 @"100" & @"0" 更改为 @(100) & @(0)