Question

我想做像facebook这样的事情，当我们拖动滚动视图直到负y时，活动指示器将显示并刷新视图。

当我实现以下代码时，它正在使用IOS。但是，在Android设备上运行时，滚动y似乎只能有0或大于0的值，并且无法滚动滚动到负区域。

root@pandora:~# LANG=C apt-get install phpapi-20100525
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package phpapi-20100525 is a virtual package provided by:
  php5-fpm 5.4.45-0+deb7u2 [Not candidate version]
  php5-cli 5.4.45-0+deb7u2 [Not candidate version]
  php5-cgi 5.4.45-0+deb7u2 [Not candidate version]
  libphp5-embed 5.4.45-0+deb7u2 [Not candidate version]
  libapache2-mod-php5filter 5.4.45-0+deb7u2 [Not candidate version]
  libapache2-mod-php5 5.4.45-0+deb7u2 [Not candidate version]

E: Package 'phpapi-20100525' has no installation candidate
root@pandora:~#

如何让它在Android上运行？

Answer 1

我猜你想要一个Xamarin.Forms解决方案，即使你没有在你的问题中提到过，因为Xamarin.Forms标签。您无需手动编码。 James Montemagno为我们完成了所有艰苦的工作。这是PullToRefreshLayout github页面的链接。您只需要在Xaml中的ScrollView位置添加PullToRefreshLayout，并将ScrollView设置为它的内容。

编辑：按照@cheesebaron的建议解释用法。

您可以安装插件Nuget包Refractored.XamForms.PullToRefresh。

然后我们可以通过添加 PullToRefreshLayout 作为ScrollView的父级来实现PullToRefresh操作。我引用了Github页面中给出的例子

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage 
xmlns="http://xamarin.com/schemas/2014/forms" 
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
x:Class="RefreshSample.Views.ScrollViewXamlPage"
xmlns:controls="clr-namespace:Refractored.XamForms.PullToRefresh;assembly=Refractored.XamForms.PullToRefresh"
Title="Xaml Scroll">
<controls:PullToRefreshLayout
      IsPullToRefreshEnabled="True"
      RefreshCommand="{Binding RefreshCommand}"
      IsRefreshing="{Binding IsBusy}"
      RefreshColor="Blue"> 
      <ScrollView
      HorizontalOptions="FillAndExpand"
      VerticalOptions="FillAndExpand">
        <StackLayout
              HorizontalOptions="FillAndExpand"
              VerticalOptions="FillAndExpand">
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Blue"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Red"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Yellow"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Purple"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Maroon"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Blue"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Red"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Yellow"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Purple"/>
            <BoxView HeightRequest="100" WidthRequest="100" BackgroundColor="Maroon"/>
        </StackLayout>
      </ScrollView>
  </controls:PullToRefreshLayout>
</ContentPage>

在ScrollView上滑动以刷新

1 个答案: