NSPredicate无法使用字典数组

问题描述

| 我有一个NSPredication格式如下：

@\"Status CONTAINS[cd] shipped\"

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;
    }
)

但是它返回一个空数组。我究竟做错了什么？谢谢     

解决方法

        你要：

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

要么：

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

您的问题是谓词格式应为

shipped

，而应为

\'shipped\'

。缺少单引号导致它试图将

[dictionary valueForKey:@\"Status\"]

与

[dictionary valueForKey:@\"shipped\"]

进行比较，而不是与字符串文字

@\"shipped\"

进行比较。     ,        您可以对字符串使用关键字

MATCHES

，

CONTAINS

等。由于状态不是字符串，我想您需要像这样检查它，

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