Xamarin.Forms中ListView中选中项的背景色是什么？

Question

在Xamarin.forms中使用ListView时，当选择一个项目时，该项目会保持原样，背景颜色相当丑陋。我能否禁用此功能？ 这是我的代码：

<StackLayout>
  <ListView x:Name="FoodList" HasUnevenRows="True" CachingStrategy="RecycleElement" ItemTapped="OnItemTapped">
    <ListView.ItemTemplate>
      <DataTemplate>
        <ViewCell>
          <StackLayout Padding="0,15,0,0" >
           <StackLayout Orientation="Horizontal" BackgroundColor="White" >
            <Image Source="{Binding image_url}" Aspect="AspectFill" HeightRequest="200" WidthRequest="200"/>
            <StackLayout Orientation="Vertical">
              <Label Text="{Binding food_name}" TextColor="Black" Style="{StaticResource MainLisTtext}" />
              <Label Text="{Binding price}" TextColor="Black" Style="{StaticResource SubLisTtext}" />
              <Label Text="{Binding food_description}" TextColor="Black" Style="{StaticResource SubLisTtext}" />
            </StackLayout>
            </StackLayout>
          </StackLayout>
        </ViewCell>vc
      </DataTemplate>
    </ListView.ItemTemplate>
  </ListView>
</StackLayout>

- John

Answer 1

使用自定义渲染器可以实现此目的。

iOS 自定义渲染器

在 iOS 上编辑 SelectionStyle 属性。

以下是将 UITableViewCellSelectionStyle 设置为 None 的示例。

using System;

using UIKit;

using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

using ListViewSample.iOS;

[assembly: ExportRenderer(typeof(ViewCell), typeof(ViewCellItemSelectedCustomRenderer))]
namespace ListViewSample.iOS
{
    public class ViewCellItemSelectedCustomRenderer : ViewCellRenderer
    {
        public override UITableViewCell GetCell(Cell item, UITableViewCell reusableCell, UITableView tv)
        {
            var cell = base.GetCell(item, reusableCell, tv);

            cell.SelectionStyle = UITableViewCellSelectionStyle.None;

            return cell;
        }
    }
}

Android自定义渲染器

1. 创建一个新的drawable，命名为ViewCellBackground.xml，并保存到Resources>drawable文件夹中：

<?xml version="1.0" encoding="UTF-8" ?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" >
        <shape android:shape="rectangle">
            <!--Change the selected color by modifying this hex value-->
            <solid android:color="#FFFFFF" />
        </shape>
    </item>
    <item>
        <shape android:shape="rectangle">
            <solid android:color="#FFFFFF" />
        </shape>
    </item>
</selector>

为ViewCell创建自定义渲染器

using System;

using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

using ListViewSample.Droid;

[assembly: ExportRenderer(typeof(ViewCell), typeof(ViewCellItemSelectedCustomRenderer))]
namespace ListViewSample.Droid
{
    public class ViewCellItemSelectedCustomRenderer : ViewCellRenderer
    {
        protected override Android.Views.View GetCellCore(Cell item, Android.Views.View convertView, Android.Views.ViewGroup parent, Android.Content.Context context)
        {
            var cell = base.GetCellCore(item, convertView, parent, context);

            cell.SetBackgroundResource(Resource.Drawable.ViewCellBackground);

            return cell;
        }
    }
}

编辑：删除不包含自定义渲染器的实现

---

示例 Xamarin.Forms ListView 应用程序

using System;
using System.Collections.Generic;

using Xamarin.Forms;

namespace ListViewSample
{
    public class CustomViewCell : ViewCell
    {
        public CustomViewCell()
        {
            View = new Label
            {
                Text = "Hello World"
            };
        }
    }

    public class ListViewContentPage : ContentPage
    {
        public ListViewContentPage()
        {
            var itemSourceList = new List<CustomViewCell>();
            itemSourceList.Add(new CustomViewCell());
            itemSourceList.Add(new CustomViewCell());

            var listView = new ListView();
            listView.ItemTemplate = new DataTemplate(typeof(CustomViewCell));
            listView.ItemsSource = itemSourceList;
            listView.SeparatorVisibility = SeparatorVisibility.None;

            Content = listView;
        }
    }

    public class App : Application
    {
        public App()
        {
            // The root page of your application

            MainPage = new NavigationPage(new ListViewContentPage());
        }
    }
}

- Brandon Minnick

---

OnListViewTextCellTapped 这是一个自定义方法吗？ - John

检查一下我的代码，我使用XAML定义了我的ListView模板。 - John

嘿，约翰！一切都进行得不错吗？ - Brandon Minnick

@BrandonMinnick 我在 Android 上尝试了一下。当我点击该项时，它显示了我所需的背景颜色，但是当我松开触摸时，它会逐渐消失。有什么想法吗？ - Baqer Naqvi

嘿@BaqerNaqvi！抱歉-我刚看到你的评论。你还在尝试解决这个问题吗？开一个新问题并把链接发给我吧！ - Brandon Minnick