mahapps metro showMessageAsync错误：“对象引用未设置为对象的实例”

Question

我有这种方法

    public async void setState(int state)
    {
        switch (state)
        {
            default:
                await this.ShowMessageAsync("Title", "Message");
                break;
        }
    }

我从MetroWindow的主管那里打电话。 但是我得到这个错误：

An exception of type 'System.NullReferenceException' occurred in MahApps.Metro.dll but was not handled in user code

Additional information: Object reference not set to an instance of an object.

在线上

await this.ShowMessageAsync("Title", "Message");

我该如何解决？

Answer 1

ShowMessageAsync（...）使用尚未构造的overlayBox，因此您需要将调用移到构造函数之外。 https://github.com/MahApps/MahApps.Metro/blob/master/MahApps.Metro/Controls/MetroWindow.cs#L468