c# - mahapps metro showMessageAsync 错误 : "Object reference not set to an instance of an object"

Question

我有这个方法

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

我从 MetroWindow 的计算器调用它。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

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

我该如何解决这个问题？

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