WinRT中的对话框服务/ MVVM体系结构中的自定义模式对话框

Question

My app has a simple search screen. One of the parameters is "Radius" (as in distance from the user's current location). The radius selector is bound to "Radius" property on the ViewModel.

The ViewModel is listening for changes on the Radius property and when it changes, if the user has not previously selected their location I would like to invoke a dialog service.

So I'd like the app to use MVVM Light's messenger service to listen for messages from the ViewModel and if it receives the message "selectlocation", it should show a "Location selector" UI as a modal dialog box.

This is easy with MessageDialog. Somehow it creates its UI and overlays it on top of whatever is on screen. How do I do the same? But with a totally bespoke modal dialog?

I could create a usercontrol and host that within the page and then have the page listen for the messages and then display the user control, however, I'd prefer it at a global level.

In pseudocode, I'd like to have a Dialog Service that does this:

void SelectLocation(onSuccessCallback, onCancelCallback)
{
    Window.Current.ShowDialog(new LocationSelectorUserControl(onSuccessCallback, onCancelCallback));
{

Virtually the same as MessageDialog but with a custom UI.

Is there any way to do this?

Answer 1

Speaking abstractly, to provide something similar, you have to create a blank window, that:

• Centers itself on screen
• Declares itself topmost
• Disables parent window until it is closed
• Implements specific ShowDialog method overload with the return value you want to obtain