IOS开发之把 JSON 数据转化成 Arrays 或者 Dictionaries

1 前言
通过 NSJSONSerialization 这个类的 JSONObjectWithData:options:error:方法来实现，把JSON 数据解析出来放在数据或者字典里面保存。

2 代码示例
TestDemo.m

[plain]
-(void)convseFromJson{ 
    NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init]; 
    [dictionary setValue:@"Anthony" forKey:@"First Name"]; 
    [dictionary setValue:@"Robbins" forKey:@"Last Name"]; 
    [dictionary setValue:[NSNumber numberWithUnsignedInteger:51] forKey:@"Age"]; 
    NSArray *arrayOfAnthonysChildren = [[NSArray alloc] initWithObjects: 
                                        @"Anthony's Son 1", 
                                        @"Anthony's Daughter 1", 
                                        @"Anthony's Son 2", 
                                        @"Anthony's Son 3", 
                                        @"Anthony's Daughter 2", nil]; 
    [dictionary setValue:arrayOfAnthonysChildren forKey:@"children"]; 
    NSError *error = nil; 
    NSData *jsonData = [NSJSONSerialization 
                        dataWithJSONObject:dictionary options:NSJSONWritingPrettyPrinted error:&error]; 
    if ([jsonData length] > 0 && error == nil){ 
        NSLog(@"Successfully serialized the dictionary into data."); 
        /* Json转数组/字典 */ 
        error = nil; 
        //转换方法 
        id jsonObject = [NSJSONSerialization 
                         JSONObjectWithData:jsonData options:NSJSONReadingAllowFragments 
                         error:&error]; 
        if (jsonObject != nil && error == nil){ 
            NSLog(@"Successfully deserialized..."); 
            //如果jsonObject是字典类 
            if ([jsonObject isKindOfClass:[NSDictionary class]]){ 
                NSDictionary *deserializedDictionary = (NSDictionary *)jsonObject; 
                NSLog(@"Dersialized JSON Dictionary = %@", deserializedDictionary); 
            } 
            //如果jsonObject是数组类 
            else if ([jsonObject isKindOfClass:[NSArray class]]){ 
                NSArray *deserializedArray = (NSArray *)jsonObject; 
                NSLog(@"Dersialized JSON Array = %@", deserializedArray); 
            } else { 
                NSLog(@"I can't deal with it"); 
            } 
        } 
        else if (error != nil){ 
            NSLog(@"An error happened while deserializing the JSON data."); } 
    } 
    else if ([jsonData length] == 0 &&error == nil){ 
        NSLog(@"No data was returned after serialization."); 
    } 
    else if (error != nil){ 
        NSLog(@"An error happened = %@", error); 
    } 
}

-(void)convseFromJson{
    NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
    [dictionary setValue:@"Anthony" forKey:@"First Name"];
    [dictionary setValue:@"Robbins" forKey:@"Last Name"];
    [dictionary setValue:[NSNumber numberWithUnsignedInteger:51] forKey:@"Age"];
    NSArray *arrayOfAnthonysChildren = [[NSArray alloc] initWithObjects:
                                        @"Anthony's Son 1",
                                        @"Anthony's Daughter 1",
                                        @"Anthony's Son 2",
                                        @"Anthony's Son 3",
                                        @"Anthony's Daughter 2", nil];
    [dictionary setValue:arrayOfAnthonysChildren forKey:@"children"];
    NSError *error = nil;
    NSData *jsonData = [NSJSONSerialization
                        dataWithJSONObject:dictionary options:NSJSONWritingPrettyPrinted error:&error];
    if ([jsonData length] > 0 && error == nil){
        NSLog(@"Successfully serialized the dictionary into data.");
        /* Json转数组/字典 */
        error = nil;
        //转换方法
        id jsonObject = [NSJSONSerialization
                         JSONObjectWithData:jsonData options:NSJSONReadingAllowFragments
                         error:&error];
        if (jsonObject != nil && error == nil){
            NSLog(@"Successfully deserialized...");
            //如果jsonObject是字典类
            if ([jsonObject isKindOfClass:[NSDictionary class]]){
                NSDictionary *deserializedDictionary = (NSDictionary *)jsonObject;
                NSLog(@"Dersialized JSON Dictionary = %@", deserializedDictionary);
            }
            //如果jsonObject是数组类
            else if ([jsonObject isKindOfClass:[NSArray class]]){
                NSArray *deserializedArray = (NSArray *)jsonObject;
                NSLog(@"Dersialized JSON Array = %@", deserializedArray);
            } else {
                NSLog(@"I can't deal with it");
            }
        }
        else if (error != nil){
            NSLog(@"An error happened while deserializing the JSON data."); }
    }
    else if ([jsonData length] == 0 &&error == nil){
        NSLog(@"No data was returned after serialization.");
    }
    else if (error != nil){
        NSLog(@"An error happened = %@", error);
    }
}
控制台结果

2013-05-13 17:26:15.726 FromJsonTest[4944:303] Successfully serialized the dictionary into data.

2013-05-13 17:26:15.728 FromJsonTest[4944:303] Successfully deserialized...

2013-05-13 17:26:15.728 FromJsonTest[4944:303] Dersialized JSON Dictionary = {

Age = 51;

"First Name" = Anthony;

"Last Name" = Robbins;

children =     (

"Anthony's Son 1",

"Anthony's Daughter 1",

"Anthony's Son 2",

"Anthony's Son 3",

"Anthony's Daughter 2"

);