使用IN NSNumbers进行NSPredicate

Question

我已经设置了一个NSPredicate来检查NSArray数字中的对象category_id是否为IN。

代码：

 ///This is working

NSArray *arr2 = [[NSArray alloc]initWithObjects:@[@3,@2,@3],nil];

[NSPredicate predicateWithFormat:@"category_id IN %@", arr2]

//This is not working

NSArray *arr = [[NSArray alloc]initWithArray:category_array]; //Array with NSNumbers

[NSPredicate predicateWithFormat:@"category_id IN %@", arr]

这工作正常但在我将category_array更改为包含NSNumber后，谓词停止工作。我如何使用NSPredicate for NSNumber？

更新： 阵列：

Category的实体：

Answer 1

You are making minor but blatant mistake here. You are adding an array @[@1,@2,@4] as an object in the array category_array.

Try:

NSArray *category_array = [[NSArray alloc] initWithArray:@[@1,@2,@4]];

or simply

NSArray *category_array = @[@1,@2,@4];

Answer 2

You are making a little mistake

try out this code

NSArray *category_array = @[@1,@2,@4];