[XAML] [UWP]在加载期间使用绑定避免NullReferenceException [英] [XAML][UWP]Avoiding NullReferenceException With Binding During Load

问题描述

我有一个UWP应用程序，它使用Binding来根据其他元素的值确定几个元素的可见性。但是，在应用程序的初始加载期间，我收到NullReferenceException，因为我绑定的元素尚未完成
加载。在进行绑定之前有没有办法等到加载完成（没有大量的代码隐藏，我想在XAML中进行绑定）？谢谢。

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Nathan Sokalski [e-mail] http://www.nathansokalski.com/

解决方案

< blockquote>

通常，由于双向绑定，我们不需要在绑定成功后考虑数据更改。但是成功建立绑定通常需要绑定到现有对象。对于NullReferenceException，你提到了
，我认为有两种方法。

首先，在收到或创建所有数据后完成绑定。

其次，设置一个默认值，如数据源的占位符，然后在收到或创建实际数据后通过双向绑定更改UI。

致以最诚挚的问候，

Roy

I have a UWP app that uses Binding to determine the Visibility of several elements based on values of other elements. However, during the initial loading of the app, I receive a NullReferenceException because the element I am binding to has not finished loading. Is there any way to wait until loading is completed before doing the binding (without a large amount of codebehind, I want to do the binding in XAML)? Thanks.

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Nathan Sokalski [e-mail] http://www.nathansokalski.com/

解决方案

Hi,

In general, because of the two-way binding, we don't need to consider the data changes after the binding is successful. But the successful establishment of a binding generally requires binding to an existing object. For the NullReferenceException you mentioned about, I think there are two ways.

First, complete the binding after all the data is received or created.

Second, set a default value like placeholder for the data source , then change the UI through two-way binding after the real data is received or created.

Best regards,

Roy

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