C# 如何在Windows应用商店应用程序中通过goback命令传递参数

在NavigationHelper中使用Binding Goback命令时，我希望将一个参数传递到我访问的上一页

XAML中的后退按钮

<Button x:Name="backButton"
                    Margin="39,59,39,0"
                    Command="{Binding NavigationHelper.GoBackCommand, ElementName=pageRoot}"
                    Style="{StaticResource NavigationBackButtonNormalStyle}"
                    VerticalAlignment="Top"
                    AutomationProperties.Name="Back"
                    AutomationProperties.AutomationId="BackButton"
                    AutomationProperties.ItemType="Navigation Button"
                    IsEnabled="{Binding IsBackEnabled}"/>

然后取回它

protected override void OnNavigatedTo(NavigationEventArgs e)
{
     string myParam = e.Parameter.ToString();
}

---

您可以在

XAML

中使用

CommandParameter

来执行此操作

<Button x:Name="backButton"
                    Margin="39,59,39,0"
                    Command="{Binding NavigationHelper.GoBackCommand, ElementName=pageRoot}"
                    CommandParameter="This is my parameter"
                    Style="{StaticResource NavigationBackButtonNormalStyle}"
                    VerticalAlignment="Top"
                    AutomationProperties.Name="Back"
                    AutomationProperties.AutomationId="BackButton"
                    AutomationProperties.ItemType="Navigation Button"
                    IsEnabled="{Binding IsBackEnabled}"/>

---

这里有一个解决方案，尽管可能有更好的方法

C#代码隐藏

在使用GoBack命令的页面中，声明GoBack方法：

private void GoBack()
{
    string myArg = "Hello";
    this.Frame.Navigate(typeof(AnotherPage), myArg);
}

public MyPage()
{
     this.InitializeComponent();
     this.navigationHelper = new NavigationHelper(this);
     this.navigationHelper.LoadState += navigationHelper_LoadState;
     this.navigationHelper.SaveState += navigationHelper_SaveState;
     this.navigationHelper.GoBackCommand = new RelayCommand(GoBack);
}

然后在页面构造函数中，只需将GoBack命令设置为GoBack方法：

private void GoBack()
{
    string myArg = "Hello";
    this.Frame.Navigate(typeof(AnotherPage), myArg);
}

public MyPage()
{
     this.InitializeComponent();
     this.navigationHelper = new NavigationHelper(this);
     this.navigationHelper.LoadState += navigationHelper_LoadState;
     this.navigationHelper.SaveState += navigationHelper_SaveState;
     this.navigationHelper.GoBackCommand = new RelayCommand(GoBack);
}

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明亮的那么我在哪里处理上一页的参数呢？看看这个