【Android】facebook api Exception： launchMode of the caller is singleInstance.

Cannot call LoginFragment with a null calling package. This can occur if the launchMode of the caller is singleInstance.

说的是不能使用单例模式，查看调用工具，发现如下代码：

        // the activity need attention , may use Login Master's Activity instead
        LoginManager.getInstance().logInWithReadPermissions(activity, permissions);

这里的activity就是问题症结所在，因为这个工具写成了单例模式，需要在 instance 不为null时，也把activity设置一遍：

public static FacebookUtils getInstance(Activity activity) {
    if (instance == null) {
        instance = new FacebookUtils(activity);
    }

        this.activity = (Activity) activity;

    return instance;
}

这样设置之后问题就解决了。

have fun

转载署源-By-KyleCe:http://blog.youkuaiyun.com/KyleCeshen/article/details/50419414