Unity PlayerPrefs 的一个坑

本周在测试 deeplink 时遇到一个闪退的问题，提取日志：

03-05 10:46:30.442  2633  2633 D Unity   : Uploading Crash Report
03-05 10:46:30.443  2633  2633 E Unity   : UnityException: TrySetSetString can only be called from the main thread.
03-05 10:46:30.443  2633  2633 E Unity   : Constructors and field initializers will be executed from the loading thread when loading a scene.
03-05 10:46:30.443  2633  2633 E Unity   : Don't use this function in the constructor or field initializers, instead move initialization code to the Awake or Start function.
03-05 10:46:30.443  2633  2633 E Unity   : 
03-05 10:46:30.443  2633  2633 E Unity   : Rethrow as TargetInvocationException: com.adjust.sdk.AdjustAndroid+DeferredDeeplinkListener.launchReceivedDeeplink(UnityEngine.AndroidJavaObject)
03-05 10:46:30.443  2633  2633 E Unity   :   at UnityEngine.AndroidJavaProxy.Invoke (System.String methodName, System.Object[] args) [0x00000] in <00000000000000000000000000000000>:0 
03-05 10:46:30.443  2633  2633 E Unity   :  
03-05 10:46:30.443  2633  2633 E Unity   : (Filename: currently not available on il2cpp Line: -1)
03-05 10:46:30.443  2633  2633 E Unity   : 

关键信息是 UnityException: TrySetSetString can only be called from the main thread，即 SetString 只能在主线程中被调用。

回到代码处：

void DeferredDeeplinkCallback(string param)
{
	UnityEngine.PlayerPrefs.SetString(key, param); 
}

这个函数是在 adjust 初始化时注入的，也就是说实际进行 SetString 确实不是 unity 主线程。

解决这个问题的一个简单思路是，将内容缓存下来，等待主线程去执行 SetString。

void checkDeeplink()
{
	if (!string.IsNullOrEmpty(_deeplink))
	{
		UnityEngine.PlayerPrefs.SetString(key, _deeplink);
		_deeplink = null;
	}
}