检查NSDictionary数组是否包含NSDictionary

Question

在我的应用程序中，我必须检查NSDictionary数组中是否有另一个NSDictionary。换句话说，我创建了一个JSON文件，并将其存储在Documents中。

现在，我正在解析这个JSON以插入一个新条目，在将这个条目插入我的JSON之前，我需要检查它是否已经存储在我的文件中。我解析了JSON，所以：

// First I read the JSON file from the folder Documents
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"data.json"];
NSString *content = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:NULL];
NSData *data = [content dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *dictContent = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
// Json parsing
NSMutableArray *array = [[NSMutableArray alloc]init];
NSMutableArray *arrayOfDictData = [[NSMutableArray  alloc]init];
if (dictContent) {
  NSDictionary *sites = [dictContent objectForKey:@"sites"];
  NSArray *site = [sites objectForKey:@"site"];
  array = [site mutableCopy];
}

然后，我有了另一个NSDictionary (dictForJson)，在其中插入了从HTML解析的数据，所以现在我需要检查字典dictForJson中的数据是否仍然在JSON文件中。

我怎么能查到呢？

dictForJson具有这样的结构：

dictForJson = @{@"name": htmlTitle,
                    @"src": path,
                    @"expiryDate": expireDate};

NSArray站点具有以下结构：

site: (
        {
        expiryDate = "29 Ago 2013";
        name = Sito4;
        src = "/Users/redoddity/Library/Application Support/iPhone Simulator/6.1/Applications/2D9EBE71-4365-448D-8AD2-A08749B8DBC1/Documents/Sito4.html";
    }
)

你知不知道？我尝试过使用[array containsObject:dictForJson]，但是NSDictionary没有排序，所以当我使用这个方法时，有时返回0，而另一些时候返回1，也许这很有用，我用下面的代码构建了JSON：

- (void)JsonCreateOrEdit {
    NSDictionary *dictSites = [[NSDictionary alloc]init];

    NSDictionary *dictSite = [[NSDictionary alloc]init];

    NSMutableArray *site = [[NSMutableArray alloc]init];

    NSDictionary *dictForJson = [[NSDictionary alloc]init];

    dictForJson = @{@"name": htmlTitle,
                    @"src": path,
                    @"expiryDate": expireDate};

    NSString* documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *filePath = [documentsPath stringByAppendingPathComponent:@"data.json"];
    BOOL fileExist = [[NSFileManager defaultManager] fileExistsAtPath:filePath];

    if (!fileExist) {
        [site addObject:dictForJson];
        dictSite = @{@"site": site};
        dictSites = @{@"sites": dictSite};
        // Creo il file Json
        NSLog(@"Il file non esiste");
        SBJsonWriter *writer = [[SBJsonWriter alloc]init];
        NSString *jsonCommand = [writer stringWithObject:dictSites];
        [CreateFile createFileIn:documentsPath with:@"data.json" andData:jsonCommand]; // This is a class method I made to create the file
    else {
        // Here there are the instructions to update the file data.json
         NSLog(@"Il file esiste");
    // Leggo il file json
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"data.json"];
    NSString *content = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:NULL];
    NSData *data = [content dataUsingEncoding:NSUTF8StringEncoding];
    NSDictionary *dictContent = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
    // Faccio il parsing del json
    NSMutableArray *array = [[NSMutableArray alloc]init];
    NSMutableArray *arrayOfDictData = [[NSMutableArray  alloc]init];
    if (dictContent) {
        NSDictionary *sites = [dictContent objectForKey:@"sites"];
        NSArray *site = [sites objectForKey:@"site"];
        array = [site mutableCopy];
        // Here I must check if in the array site there are the same information I'm trying to insert
    }
}

Answer 1

我做到了！:)我做到了：

{
        // Aggiorno il file
        NSLog(@"Il file esiste");
        // Leggo il file json
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
        NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"data.json"];
        NSString *content = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:NULL];
        NSData *data = [content dataUsingEncoding:NSUTF8StringEncoding];
        NSDictionary *dictContent = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
        // Faccio il parsing del json
        NSMutableArray *array = [[NSMutableArray alloc]init];
        NSMutableArray *arrayOfDictData = [[NSMutableArray  alloc]init];
        if (dictContent) {
            NSDictionary *sites = [dictContent objectForKey:@"sites"];
            NSArray *site = [sites objectForKey:@"site"];
            NSDictionary *dict = [site objectAtIndex:0];
            NSLog(@"dictForJson = %@\ndict = %@", dictForJson, dict);
            NSString *name = [dict objectForKey:@"name"];
            NSLog(@"name: %@", name);
            array = [site mutableCopy];

        }

而且起作用了！谢谢你给我时间！

Answer 2

NSPredicate *aPredicate = [NSPredicate predicateWithFormat:@"%K LIKE[c] %@", @"name", @"htmlTitle"];
NSArray *theFilteredArray = [mainArrayOfDictionry filteredArrayUsingPredicate:aPredicate];

if ([theFilteredArray count]){
    NSLog(@"Dictionay Exists");
}else{
     NSLog(@"Dictionay does not Exists");
}

在第一个语句中，第一个参数是"Key“，第二个参数是dictionay的实际值。

，我假设如下:

NSDictionary *dictForJson = @{@"name": htmlTitle,
                    @"src": path,
                    @"expiryDate": expireDate};


NSArray *mainArrayOfDictionry = (

"dictForJson" : @{@"name": htmlTitle,
                    @"src": path,
                    @"expiryDate": expireDate};
),
(),
(),
(),
.
.
.
)

*希望这能帮到你。