删除使用NSPredicate对象(Remove objects using NSPredicate

我有有许多子词典的词典folloving。 我怎样才能在那里删除对象isChanged = 1使用从母体字典NSPredicate ？

{
    "0_496447097042228" =     {
        cellHeight = 437;
        isChanged = 1;
    };
    "100000019882803_193629104095337" =     {
        cellHeight = 145;
        isChanged = 0;
    };
    "100002140902243_561833243831980" =     {
        cellHeight = 114;
        isChanged = 1;
    };
    "100004324964792_129813607172804" =     {
        cellHeight = 112;
        isChanged = 0;
    };
    "100004324964792_129818217172343" =     {
        cellHeight = 127;
        isChanged = 0;
    };
    "100004324964792_129835247170640" =     {
        cellHeight = 127;
        isChanged = 1;
    };
}

Answer 1:

作为一个简单的替代使用NSPredicate，您可以使用的NSDictionary的内置keysOfEntriesPassingTest:这个答案假定“isChanged”是一个NSString和值为0或1是一个NSNumber：

NSSet *theSet = [dict keysOfEntriesPassingTest:^(id key, id obj, BOOL *stop) {
    return [obj[@"isChanged"] isEqualToNumber: @1];
}];

返回的集合是通过测试键的列表。 从那里，你可以删除所有与匹配：

[dict removeObjectsForKeys:[theSet allObjects]];

Answer 2:

我解决我的问题通过以下方式：

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"isChanged == %d", 1];

NSArray *allObjs = [parentDict.allValues filteredArrayUsingPredicate:predicate];

[allObjs enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
    NSMutableArray *keys = [[NSMutableArray alloc] initWithCapacity:0];
    [keys setArray:[parentDict allKeysForObject:obj]];
    [parentDict removeObjectsForKeys:keys];
    [keys release];
}];

Answer 3:

当你有字典的数组比你可以使用NSPredicate删除所选类别的数据

这里是代码

NSString *selectedCategory = @"1";

//filter array by category using predicate
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"isChanged == %@", selectedCategory];

NSArray *filteredArray = [yourAry filteredArrayUsingPredicate:predicate];

[yourAry removeObject:[filteredArray objectAtIndex:0]];  

但是，在你的问题的数据是不是在阵列它在字典

你的数据应该是这种格式

(
 {
     cellHeight = 437;
     isChanged = 1;
 },
 {
     cellHeight = 145;
     isChanged = 0;
 },
 {
     cellHeight = 114;
     isChanged = 1;
 }
 )

文章来源: Remove objects using NSPredicate