Sprite Kit iOS7 - SKNode UserData 属性不存储值 [英] Sprite Kit iOS7 - SKNode UserData property not storing values

问题描述

我认为这项工作很容易完成，但是我不明白为什么我的 NSMutableDictionary 属性没有按我预期的那样工作.

I would think this work work easily, however I cannot understand why my NSMutableDictionary property is not working as I would have expected.

[self.testSprite.userData setValue:@"CAT" forKey:@"key"];
NSLog(@"%@", [self.testSprite.userData objectForKey:@"key"]);
NSLog(@"%lu", [self.testSprite.userData count]);

我正在重新调整 (null) 和 0.

I am retuning (null) and 0.

使用 spriteNode 用户数据有什么特别的技巧吗?

Is there a special trick for using the spriteNode userdata ?

谢谢

推荐答案

userData 属性最初为零.你必须先创建一个字典并分配它:

The userData property is initially nil. You have to create a dictionary and assign it first:

self.testSprite.userData = [NSMutableDictionary dictionary];

[self.testSprite.userData setValue:@"CAT" forKey:@"key"];
NSLog(@"%@", [self.testSprite.userData objectForKey:@"key"]);
NSLog(@"%lu", [self.testSprite.userData count]);

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