一个PhotoChooserTask后应用程序任务栏图标按钮单击事件不解雇 [英] ApplicationBar icon button click event not fired after a PhotoChooserTask

问题描述

我不能得到ApplicationBarIconButton的点击事件在一定条件下火

I can't get the ApplicationBarIconButton's click event to fire under certain conditions.

我试图简化再现它所需的步骤：

I tried to simplify the steps required to reproduce it:

1）创建一个新的Windows Phone应用程序

1) Create a new Windows Phone Application

2）添加新的页面（的Page1.xaml）

2) Add a new Page (Page1.xaml)

3）添加在MainPage.xaml中一个简单的按钮启动一个PhotoChooserTask并导航到Completed事件的Page1.xaml

3) Add a simple button on MainPage.xaml launching a PhotoChooserTask and navigate to Page1.xaml on the Completed event

public partial class MainPage : PhoneApplicationPage
{
    PhotoChooserTask photo;

    public MainPage()
    {
        InitializeComponent();
        photo = new PhotoChooserTask();
        photo.Completed += OnCameraCaptureTaskCompleted;
    }

    void OnCameraCaptureTaskCompleted(object sender, PhotoResult args)
    {
        this.NavigationService.Navigate(new Uri("/Page1.xaml", UriKind.Relative));
    }

    private void button1_Click(object sender, RoutedEventArgs e)
    {
        photo.Show();
    }
}

6）取消注释的Page1.xaml的应用程序任务栏部分，其中一个按钮的Click事件设置为一个新的事件处理程序

6) Uncomment the ApplicationBar section of Page1.xaml and set the click event of one of the buttons to a new event handler

<phone:PhoneApplicationPage.ApplicationBar>
    <shell:ApplicationBar IsVisible="True">
        <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Won't work" Click="ApplicationBarIconButton_Click" />
    </shell:ApplicationBar>
</phone:PhoneApplicationPage.ApplicationBar>

    private void ApplicationBarIconButton_Click(object sender, EventArgs e)
    {
        MessageBox.Show("This messagebox won't show!");
    }

启动它

Launch it

点击按钮，选择一张图片=>您将被重定向到的Page1.xaml

Click on the button to select a picture => you are redirected to Page1.xaml

点击ApplicationBarIconButton按钮：该事件不会触发

Click on the ApplicationBarIconButton button : the event isn't fired!

我错过了什么，或这是一个错误吗？

Did I miss something or that's a bug?

推荐答案

在张贴的问题后， WP7的官方论坛（这里是链接到的问题），我有一个答复，告诉这是一个已知的问题。

After posting that question on the WP7 official forum (here is the link to the question), I had a response telling that it's a known issue.

下面是似乎是官方的解决方法：

Here is what seems to be the "official" workaround:

    void OnCameraCaptureTaskCompleted(object sender, PhotoResult args)
    {
        //Delay navigation until the first navigated event
        NavigationService.Navigated += new NavigatedEventHandler(navigateCompleted);
    }

    void navigateCompleted(object sender, EventArgs e)
    {
        //Do the delayed navigation from the main page
        this.NavigationService.Navigate(new Uri("/Page1.xaml", UriKind.Relative));
        NavigationService.Navigated -= new NavigatedEventHandler(navigateCompleted);
    }

（你需要添加使用系统.Windows.Navigation; ）

马特的变通办法太多，但我更喜欢使用NavigatedEventHandler比Dispatcher.BeginInvoke解决方案

Matt's workaround works too but I prefer using the NavigatedEventHandler than the Dispatcher.BeginInvoke solution.

这篇关于一个PhotoChooserTask后应用程序任务栏图标按钮单击事件不解雇的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！