Xamarin - 清算的ListView选择 [英] Xamarin - clearing ListView selection

问题描述

我实际上这段代码工作。

I am actually working with this piece of code

using System;
using Xamarin.Forms;
using System.Diagnostics;

namespace CryptoUI
{
    public class HomePage : Xamarin.Forms.MasterDetailPage
    {
        public HomePage()
        {
        // Set up the Master, i.e. the Menu
            Label header = new Label
            {
                Text = "MENU",
                Font = Font.SystemFontOfSize(20, FontAttributes.Bold),
                HorizontalOptions = LayoutOptions.Center
            };
        // create an array of the Page names
        string[] myPageNames = {
            "Main",
            "Page 2",
            "Page 3",
        };

        // Create ListView for the Master page.
        ListView listView = new ListView
        {
            ItemsSource = myPageNames,
        };

        // The Master page is actually the Menu page for us
        this.Master = new ContentPage
        {
            Title = "Test",
            Content = new StackLayout
            {
                Children = 
                {
                    header, 
                    listView
                },
            }
        };

        // Define a selected handler for the ListView contained in the Master (ie Menu) Page.
        listView.ItemSelected += (sender, args) =>
        {
            // Set the BindingContext of the detail page.
            this.Detail.BindingContext = args.SelectedItem;

            string currentPage = this.GetType().Name.ToString();

            // This is where you would put your "go to one of the selected pages"
            if(listView.SelectedItem.Equals("Main") && !currentPage.Equals("HomePage")){
                AsyncPush(new HomePage());
            }
            else if(listView.SelectedItem.Equals("Page 2") && !currentPage.Equals("SecondPage")){
                AsyncPush(new SecondPage());
            }
            else if(listView.SelectedItem.Equals("Page 3") && !currentPage.Equals("ThirdPage")){
                AsyncPush(new ThirdPage());
            }               

            // Show the detail page.
            this.IsPresented = false;
        };
            listView.ItemSelected += (senders, e) => {
                if (e.SelectedItem == null) return; // don't do anything if we just de-selected the row
                // do something with e.SelectedItem
                ((ListView)senders).SelectedItem = null; // de-select the row
            };

        // Set up the Detail, i.e the Home or Main page.
        Label myHomeHeader = new Label
        {
            Text = "Home Page",
            HorizontalOptions = LayoutOptions.Center
        };

        string[] homePageItems = { "Alpha", "Beta", "Gamma" };
        ListView myHomeView = new ListView {
            ItemsSource = homePageItems,
        };

        var myHomePage = new ContentPage();

        myHomePage.Content = new StackLayout
        {
            Children = 
            {
                myHomeHeader, 
                myHomeView
            } ,
        };
        this.Detail = myHomePage;
    }

        public async void AsyncPush(Page page)
        {
            await Navigation.PushAsync(page);
        }
    }
}

此代码实际上给出了一个简单的弹出式菜单，使用Xamarin窗体技术。
目前，我想了解我怎么能轻松清除的ListView选择后，我选择了我想要的页面，前往！

This code actually shows an easy FlyOut menu, using the Xamarin Forms technologies. I am currently trying to understand how I could easily clear the ListView selection after I have selected which page I want to head to!

我发现这片在Xamarin的网站代码的开发者（的http：//开发商.xamarin.com /导游/跨平台/ xamarin表单/劳动与/列表视图/ ）;

I found this piece of code on Xamarin's website for devs (http://developer.xamarin.com/guides/cross-platform/xamarin-forms/working-with/listview/);

listView.ItemSelected += (sender, e) => {
    if (e.SelectedItem == null) return; // don't do anything if we just de-selected the row
    // do something with e.SelectedItem
    ((ListView)sender).SelectedItem = null; // de-select the row
};

但我目前不能弄清楚如何我应该把它与我的代码集成上面有：）

But I can't currently figure out how I should integrate it with my code above there :)

推荐答案

你两次分配ItemSelected处理程序，这是一个坏主意。所有你应该做的就是这一行添加到现有ItemSelected处理程序

You're assigning the ItemSelected handler twice, which is a bad idea. All you should have to do is add this line to your existing ItemSelected handler

  ((ListView)sender).SelectedItem = null; 

这篇关于Xamarin - 清算的ListView选择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！