CODEWITHSUNDEEP
uwpc++-cx
YMDW
YMDW

Reputation: 411

UWP C++ ContentDialog PrimaryButtonCommand or PrimaryButtonClick

I'm trying to use ContentDialog^ in a UWP C++ app. With MessageDialog^ you can easily set the buttons and commands Windows::UI::Popups::UICommand they invoke when touched

MessageDialog^ msg = ref new MessageDialog("Data changed - Save?");
msg->Title = "Warning";

// Add commands and set their callbacks.
UICommand^ continueCommand = ref new UICommand("Yes", ref new UICommandInvokedHandler(this, &MainPage::CommandInvokedHandler));
UICommand^ upgradeCommand = ref new UICommand("No", ref new UICommandInvokedHandler(this, &MainPage::CommandInvokedHandler));
UICommand^ cancelCommand = ref new UICommand("Cancel", ref new UICommandInvokedHandler(this, &MainPage::CommandInvokedHandler));

then you can easily access the value sent to the CommandInvokedHandler by

void MainPage::CommandInvokedHandler(Windows::UI::Popups::IUICommand^ command)
{
    // Display message
    if (command->Label == "Yes") {
        Save();
    } else if (command->Label == "No") {
        Skip();
    } else if (command->Label == "Cancel") {
        //do nothing
    }
}

However, the content dialog works completely differently. It's created like this

TextBox^ inputTextBox = ref new TextBox();
inputTextBox->AcceptsReturn = false;
inputTextBox->Height = 32;
ContentDialog^ dialog = ref new ContentDialog();

dialog->Content = inputTextBox;
dialog->Title = "Rename";
dialog->IsSecondaryButtonEnabled = true;
dialog->PrimaryButtonText = "Ok";
dialog->SecondaryButtonText = "Cancel";
dialog->ShowAsync();

I either need to set the property dialog->PrimaryButtonCommand that for some (unknown bizarre) reason uses the completely different Windows::UI::Xaml::Input::ICommand...
Or should I use the dialog->PrimaryButtonClick?

I'm struggling to find any C++ examples anywhere and the documentation doesn't clear anything up.

Upvotes: 4

Views: 2042

Answers (1)

Jay Zuo
Jay Zuo

Reputation: 15758

You can either use PrimaryButtonCommand or PrimaryButtonClick in ContentDialog. Both of them will be invoked when the primary button has been tapped. The difference between them is that PrimaryButtonClick is a event, but PrimaryButtonCommand is a property whose type is ICommand. Please note ICommand is not the same as U​ICommand used in MessageDialog, they are totally two different things.

ICommand is more used with XAML Binding. To use it, we will implement ICommand interface and then use in view model. For more info, please refer to Executing commands in a view model.

And in your case, as you are creating content dialog in code-behind, so I think you can just subscribe to PrimaryButtonClick event with an event handler method like the following: 

void MainPage::Button_Click(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
    TextBox^ inputTextBox = ref new TextBox();
    inputTextBox->AcceptsReturn = false;
    inputTextBox->Height = 32;
    ContentDialog^ dialog = ref new ContentDialog();

    dialog->Content = inputTextBox;
    dialog->Title = "Rename";
    dialog->IsSecondaryButtonEnabled = true;
    dialog->PrimaryButtonText = "Ok";
    dialog->SecondaryButtonText = "Cancel";
    dialog->PrimaryButtonClick += ref new Windows::Foundation::TypedEventHandler<Windows::UI::Xaml::Controls::ContentDialog ^, Windows::UI::Xaml::Controls::ContentDialogButtonClickEventArgs ^>(this, &MainPage::OnPrimaryButtonClick);
    dialog->ShowAsync();
}


void MainPage::OnPrimaryButtonClick(Windows::UI::Xaml::Controls::ContentDialog ^sender, Windows::UI::Xaml::Controls::ContentDialogButtonClickEventArgs ^args)
{
    // Do something useful here
}

Upvotes: 4

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