NSPredicate 不适用于字典数组

Question

我有一个 NSPredicate ，其格式如下：@"Status CONTAINS[cd] returned"

我有一个字典数组，这是一个示例：

{
        {
        Category = "Category 4";
        Comp = "Category 4";
        Depth = 02;
        Grade = New;
        Length = 02;
        Location = "Thousand Oaks, CA";
        Name = "3ply Mat";
        Owner = "Owner 3";
        PUP = 2;
        Status = Shipped;
        "Unit Number" = 20110507113852351;
        Width = 02;
    },
        {
        Category = "Category 4";
        Comp = "Category 4";
        Depth = 02;
        Grade = New;
        Length = 02;
        Location = "Thousand Oaks, CA";
        Name = "3ply Mat";
        Owner = "Owner 3";
        PUP = 2;
        Status = Shipped;
        "Unit Number" = 20110516094641587;
        Width = 02;
    }
)

但它返回一个空数组。我做错了什么？谢谢

Answer 1

您想要：

[NSPredicate predicateWithFormat:@"Status =[cd] 'shipped'"];

或者：

[NSPredicate predicateWithFormat:@"Status =[cd] %@", @"shipped"];

您的问题是您的谓词格式已shipped，而它本应具有'shipped'。缺少单引号意味着它试图将 [dictionary valueForKey:@"Status"] 与 [dictionary valueForKey:@"shipped"] 进行比较，而不是与字符串进行比较文字@“已发货”。

Answer 2

您可以对字符串使用关键字 MATCHES、CONTAINS 等。由于 Status 不是字符串，我想您需要这样检查，

[NSPredicate predicateWithFormat:@"Status = %d", Shipped];