我正在尝试使用谓词从 NSMutableArray 中获取 NSDictionary:
NSMutableArray *arr = [NSMutableArray arrayWithArray:[self createArrayFromCSV:savedCSV withDelimiter:delim firstLineContainsKeys:YES]];
// The method «createArrayFromCSV returns an array of dictionaries
NSLog(@"Array %@", [arr objectAtIndex:0]); // works fine
// spits out:
// Array {
// product = "MyProduct";
// "id_product" = 29;
// }
// idField and idVal are passed to the method
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(%@ == %@)", idField, idVal];
NSLog(@"predicate %@", predicate);
// spits out predicate "id_product" == "29"
NSArray *filtered = [arr filteredArrayUsingPredicate:predicate];
NSLog(@"Filtered %@", filtered);
// Filtered is always empty
有什么想法我做错了吗？？？
[已解决] 显然，我弄错了格式字符串。这有效:
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(%K == %@)", idField, idVal];
根据这篇文章NSPredicate predicateWithFormat passing in name of attribute
对于键或键路径，必须使用@K
最佳答案
显然，我把格式字符串弄错了。这有效:
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(%K == %@)", idField, idVal];
根据这篇文章NSPredicate predicateWithFormat传入属性名称
对于键或键路径，必须使用@K
关于cocoa - 使用 nspredicate 使用字典过滤数组失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16751227/