Question

我在MainPage.xaml中有一个图像元素，在SettingsContract1.xaml中有一个弹出按钮，当点击弹出项目时，打开了文件选择器，我想在主页面中设置图像的图像源，并从中选取文件filepicker。如何从SettingsContract1.xaml

访问图像 MainPage.xaml中的

图像

<Image x:Name="img" HorizontalAlignment="Left" Height="332" VerticalAlignment="Top" Width="778" Margin="349,406,0,0"/>

SettingsContract1.xaml中的menuflyout子

Private Sub chooseFile_Click(sender As Object, e As RoutedEventArgs) Handles chooseFile.Click
    Dim filePicker As FileOpenPicker
    filePicker = New FileOpenPicker()
    filePicker.ViewMode = PickerViewMode.Thumbnail
    filePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary
    filePicker.FileTypeFilter.Add(".png")
    Dim file As StorageFile = Await filePicker.PickSingleFileAsync()

    Using filestream As Streams.IRandomAccessStream = Await file.OpenAsync(FileAccessMode.Read)
        Dim bitmapImage As Windows.UI.Xaml.Media.Imaging.BitmapImage = New BitmapImage
        bitmapImage.SetSource(filestream)
        img.Source = bitmapImage 'gives an error
    End Using

End Sub

Answer 1

您可以创建一个映射到MainPage的变量，然后访问那里的任何公共成员表单。

Dim mp = TryCast(Application.Current.RootVisual, MainPage)
If Not mp Is Nothing Then
  mp.img.Source = bitmapImage
End If

Answer 2

找到答案here并将其转换为VB

Private Async Sub chooseFile_Click(sender As Object, e As RoutedEventArgs) Handles chooseFile.Click
    Dim mapImage As Frame = Window.Current.Content
    Dim mainPage As MainPage = mapImage.Content
    Dim filePicker As FileOpenPicker
    filePicker = New FileOpenPicker()
    filePicker.ViewMode = PickerViewMode.Thumbnail
    filePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary
    filePicker.FileTypeFilter.Add(".png")
    Dim file As StorageFile = Await filePicker.PickSingleFileAsync()

    Using filestream As Streams.IRandomAccessStream = Await file.OpenAsync(FileAccessMode.Read)
        Dim bitmapImage As Windows.UI.Xaml.Media.Imaging.BitmapImage = New BitmapImage
        bitmapImage.SetSource(filestream)
        mainPage.img.Source = bitmapImage
    End Using

End Sub

如何从另一个页面访问MainPage.xaml控件

2 个答案: