C# PropertyChangedCallback在WinRT中OnApplyTemplate之前调用

我正在创建一个WinRT CustomControl，该控件具有PropertyChangedCallback的依赖属性。在该回调方法中，我尝试在使用GetTemplateChild方法从OnApplyMethod检索的控件的某些部分上设置值

问题是PropertyChangedCallback在OnApplyTemplate之前被调用，因此控件部分仍然为null

我发现的一个解决方法是在自定义控件的加载事件中调用此DP。那样的话，一切对我来说都很好。但每种情况都不适用。假设有人想通过xaml绑定这些值，那么问题再次出现

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是否有人对此问题有任何永久性的解决办法。

当我想做您所描述的事情时，以下是我遵循的一般模式：

private void OnFooChanged(...)
{
    if (someNamedPart != null && someOtherNamedPart != null && ...)
    {
        // Do something to the named parts that are impacted by Foo 
        // when Foo changes.
    }
}

private void FooChangedCallback(...)
{
    // Called by WinRT when Foo changes
    OnFooChanged(...)
}

protected override void OnApplyTemplate(...)
{
    // Theoretically, this can get called multiple times - every time the 
    // consumer of this custom control changes the template for this control.
    // If the control has named parts which must react to the properties
    // this control exposes, all that work must be done here EVERY TIME
    // a new template is applied.

    // Get and save named parts as local variables first

    OnFooChanged(...)
}

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希望伪代码有帮助

当我想做你所描述的事情时，以下是我遵循的一般模式：

private void OnFooChanged(...)
{
    if (someNamedPart != null && someOtherNamedPart != null && ...)
    {
        // Do something to the named parts that are impacted by Foo 
        // when Foo changes.
    }
}

private void FooChangedCallback(...)
{
    // Called by WinRT when Foo changes
    OnFooChanged(...)
}

protected override void OnApplyTemplate(...)
{
    // Theoretically, this can get called multiple times - every time the 
    // consumer of this custom control changes the template for this control.
    // If the control has named parts which must react to the properties
    // this control exposes, all that work must be done here EVERY TIME
    // a new template is applied.

    // Get and save named parts as local variables first

    OnFooChanged(...)
}

---

希望伪代码有帮助

这会发生什么情况？在应用模板之前何时触发回调方法？在XAML中设置属性值时，它们会立即触发回调。这通常发生在XAML调用OnApplyTemplate之前。会发生什么情况？在应用模板之前何时触发回调方法？在XAML中设置属性值时，它们会立即触发回调。这通常发生在XAML调用OnApplyTemplate之前。