后退按钮按下事件Xamarin.Forms上的“确认对话框" [英] Confirmation Dialog on back button press event Xamarin.Forms

问题描述

我被困在Xamarin.Forms应用程序中的某个地方

I am stuck at one point in Xamarin.Forms application

在返回"按钮上按一下，我只是想让用户确认他是否真的要退出， "OnBackButtonPressed"我想显示警报"对话框并作为用户响应继续进行.

On Back button press simply I want to ask user to confirm whether he really wants to exit or not, "OnBackButtonPressed" I want to show Alert dialog and proceed as user response.

但是"OnBackButtonPressed"不是异步我无法编写等待DisplayAlert ... 请指导我如何实现此功能?

But "OnBackButtonPressed" is not Async I cannot write await DisplayAlert... Please direct me how should i implement this feature?

我正在使用ContentPage作为NavigationPage的根页面

I am using ContentPage as my root Page of NavigationPage

    public class frmHome : ContentPage

这是代码:

protected override bool OnBackButtonPressed()
{
    var result = await  this.DisplayAlert("Alert!", "Do you really want to exit?", "Yes", "No");

    if (result)
        {
            //user wants to exit
            //Terminate application
        }
        else
        {
            //Dont do anything
        }
}

推荐答案

    protected override bool OnBackButtonPressed()
    {
        Device.BeginInvokeOnMainThread(async() => {
            var result = await this.DisplayAlert("Alert!", "Do you really want to exit?", "Yes", "No");
            if (result) await this.Navigation.PopAsync(); // or anything else
        });

        return true;
    }

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