获取 JSON 中所有对象的特定键值

Question

这是我的 JSON:

{
"Frames":
[
{"Image":"1.png", "Time":"0.04"},
{"Image":"2.png", "Time":"0.04"},
{"Image":"3.png", "Time":"0.04"},
{"Image":"4.png", "Time":"0.04"},
{"Image":"5.png", "Time":"0.04"},
{"Image":"6.png", "Time":"0.04"},
{"Image":"7.png", "Time":"0.04"},
{"Image":"8.png", "Time":"0.04"},
{"Image":"9.png", "Time":"0.04"},
{"Image":"10.png", "Time":"0.04"},
{"Image":"11.png", "Time":"0.04"},
{"Image":"12.png", "Time":"0.04"},
{"Image":"13.png", "Time":"0.04"},
{"Image":"14.png", "Time":"0.04"},
{"Image":"15.png", "Time":"0.04"},
{"Image":"16.png", "Time":"0.04"},
{"Image":"17.png", "Time":"0.04"},
{"Image":"18.png", "Time":"0.04"},
{"Image":"19.png", "Time":"0.04"},
{"Image":"20.png", "Time":"0.04"}
]
}

我想将 Image 键的每个值（这里总共 20 个）保存在一个 NSMutableArray 名称 imageNamesArray 中，并将 Time 键的每个值保存在另一个 NSMutableArray 姓名 durationArray.

我尝试使用 [dictionary valueForKeyPath:@"Frames.Image"]，如下所示：

NSString *filePath = [[NSBundle mainBundle] pathForResource:@"animation" ofType:@"json"];
NSData *content = [[NSData alloc] initWithContentsOfFile:filePath];

NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
dictionary = [NSJSONSerialization JSONObjectWithData:content options:kNilOptions error:nil];
NSMutableDictionary *detailsDictionary = [[NSMutableDictionary alloc] init];


self.imageNamesArray = [[NSMutableArray alloc] init];
self.durationArray = [[NSMutableArray alloc] init];

[self.imageNamesArray addObject:[dictionary valueForKeyPath:@"Frames.Image"]];
[self.durationArray addObject:[dictionary valueForKeyPath:@"Frames.Time"]];

NSLog(@"imageNamesArray %@", [imageNamesArray objectAtIndex:0]);
NSLog(@"durationArray %@", durationArray);

但是，它保存了imageNamesArray第一行的所有Image键值（我的意思是[imageNamesArray objectAtIndex:0]）。 durationArray 也一样。我该怎么办？非常感谢。

输出将是

imageNamesArray = 1.png, 2.png...........20.PNG
durationArray = 0.04, 0.04...............0.04

Answer 1

可以遍历Frames Array中的Each NSDictionary，可以将object添加到相应的Array中。

for (NSDictionary *dict in dictionary[@"Frames"]) {
    [_imageNamesArray addObject:dict[@"Image"]];
    [_durationArray addObject:dict[@"Time"]];
}
NSLog(@"imageNamesArray %@--%ld", _imageNamesArray, _imageNamesArray.count);
NSLog(@"durationArray %@--%ld", _durationArray, _durationArray.count);

Answer 2

您应该使用第一个帧对象作为数组并在其中循环。

        NSString *filePath = [[NSBundle mainBundle] pathForResource:@"animation" ofType:@"json"];
        NSData *content = [[NSData alloc] initWithContentsOfFile:filePath];

        NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
        dictionary = [NSJSONSerialization JSONObjectWithData:content options:kNilOptions error:nil];

    //this is your loop array
        NSArrray *objArray=[dictionary objectForKey:@"Frames"];

        NSMutableDictionary *detailsDictionary = [[NSMutableDictionary alloc] init];


        self.imageNamesArray = [[NSMutableArray alloc] init];
        self.durationArray = [[NSMutableArray alloc] init];

        for (NSDictionary *dic in objArray) {
            [self.imageNamesArray addObject:dic[@"Image"]]; 
            [self.durationArray addObject:dic[@"Time"]]; 
       }

        NSLog(@"imageNamesArray %@", [imageNamesArray objectAtIndex:0]);
        NSLog(@"durationArray %@", durationArray);

获取 JSON 中所有对象的特定键值

Getting a particular key value for all object in JSON

ios

objective-c

json

nsmutablearray

nsmutabledictionary