[开源,学习,分享]UWP第三方简书客户端分享

缓存支持同步和异步的两种方式,分别实现了两个接口:

internal interface IStorage {  void AddItem(string key, object value);  void UpdateItem(string key, object value);  bool ContainItem(string key);  void FlushAll();  T GetItem<T>(string key) where T : class;  List<T> GetItems<T>(string key) where T : class;  bool RemoveItem(string key);  long GetSize(); } 

interface IStorageAsync {  Task AddItemAsync(string key, object value);  Task UpdateItemAsync(string key, object value);  Task<bool> ContainItemAsync(string key);  Task FlushAllAsync();  Task<T> GetItemAsync<T>(string key) where T : class;  Task<List<T>> GetItemsAsync<T>(string key) where T : class;  Task<bool> RemoveItemAsync(string key);  long GetSize(); } 

通过Key和Value的方式实现增减删改.

public async Task<WeiboResult> ShareTextAsync(string text) {  if (text == null)  {   throw new ArgumentNullException(nameof(text));  }  if (string.IsNullOrWhiteSpace(text))  {   throw new ArgumentException("Text could not be empty", nameof(text));  }  if (!UserInfo.CheckUseable())  {   string authorizeCode = await this.GetAuthorizeCodeAsync();   await this.Authorize(authorizeCode);  }  Uri uri = new Uri("https://api.weibo.com/2/statuses/update.json");  Dictionary<string, string> pairs = new Dictionary<string, string>();  pairs.Add("access_token", UserInfo.Token);  pairs.Add("status", text);  HttpFormUrlEncodedContent content = new HttpFormUrlEncodedContent(pairs);  using (HttpClient client = new HttpClient())  {   HttpResponseMessage response;   try   {    response = await client.PostAsync(uri, content);   }   catch (Exception ex)   {    throw new Exception("Network error", ex);   }   return await response.Content.ReadAsJsonAsync<WeiboResult>();  } } public async Task<WeiboResult> ShareImageAsync(byte[] image, string text) {  if (image == null)  {   throw new ArgumentNullException(nameof(image));  }  if (text == null)  {   throw new ArgumentNullException(nameof(text));  }  if (string.IsNullOrWhiteSpace(text))  {   throw new ArgumentException("Text could not be empty", nameof(text));  }  if (!UserInfo.CheckUseable())  {   string authorizeCode = await this.GetAuthorizeCodeAsync();   await this.Authorize(authorizeCode);  }  Uri uri = new Uri("https://upload.api.weibo.com/2/statuses/upload.json");  HttpBufferContent bufferContent = new HttpBufferContent(image.AsBuffer());  HttpMultipartFormDataContent content = new HttpMultipartFormDataContent();  content.Add(new HttpStringContent(UserInfo.Token), "access_token");  content.Add(new HttpStringContent(text), "status");  content.Add(bufferContent, "pic", "pic.jpg");  using (HttpClient client = new HttpClient())  {   HttpResponseMessage response;   try   {    response = await client.PostAsync(uri, content);   }   catch (Exception ex)   {    throw new Exception("Network error", ex);   }   return await response.Content.ReadAsJsonAsync<WeiboResult>();  } } 

异步线程的处理我在上一篇《 讲讲我在Windows10(uwp)开发中遇到的一些坑 》已经说过了.这里说下贴一下异步Command的代码:

public class AsyncCommand : AsyncCommandBase {  private readonly Func<Task> command;  public AsyncCommand(Func<Task> command)  {   this.command = command;  }  public override bool CanExecute(object parameter)  {   return true;  }  public override Task ExecuteAsync(object parameter)  {   return command();  } } 

对于UWP的下拉刷新,我在博客园里看到了几种实现方式:

UWP的一种下拉刷新实现

只贴了一种,因为目前实现下拉刷新的方式都是ListView外部套一个ScrollViewer来实现,这种实现方式有个严重的问题就是:ListView内部也是有一个ScrollViewer,当滑动的时候,会出现ListView内部的ScrollViewer被压缩,这样直接导致了下拉刷新的失败.

我这里思考了另一种方式,就是对ListView内部的ScrollViewer进行操作.

<ScrollViewer Margin="0,0,0,-100" RenderTransformOrigin="0.5,0.5" x:Name="ScrollViewer" AutomationProperties.AccessibilityView="Raw" BringIntoViewOnFocusChange="{TemplateBinding ScrollViewer.BringIntoViewOnFocusChange}" HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}" IsHorizontalScrollChainingEnabled="{TemplateBinding ScrollViewer.IsHorizontalScrollChainingEnabled}" IsVerticalScrollChainingEnabled="{TemplateBinding ScrollViewer.IsVerticalScrollChainingEnabled}" IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" TabNavigation="{TemplateBinding TabNavigation}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}" ZoomMode="{TemplateBinding ScrollViewer.ZoomMode}">  <ScrollViewer.RenderTransform>   <CompositeTransform TranslateY="-100" />  </ScrollViewer.RenderTransform>  <Grid>   <Grid.RowDefinitions>    <RowDefinition Height="auto" />    <RowDefinition Height="*" />   </Grid.RowDefinitions>   <Border Height="{TemplateBinding RefreshHeaderHeight}" x:Name="PullToRefreshIndicator" Background="Transparent">    <Grid HorizontalAlignment="Center">     <Grid.ColumnDefinitions>      <ColumnDefinition Width="auto" />      <ColumnDefinition Width="auto" />     </Grid.ColumnDefinitions>     <Grid Width="40">      <Viewbox x:Name="Arrow" Height="15" VerticalAlignment="Top" Margin="0,4,0,0" RenderTransformOrigin="0.5,0.5">       <Viewbox.RenderTransform>        <CompositeTransform Rotation="180" />       </Viewbox.RenderTransform>       <Image Source="ms-appx:///Assets/arrow.png" Width="12" Height="12.9999"/>       <!--<Path    Width="12"    Height="12.9999"    Stretch="Fill"    Fill="{TemplateBinding ArrowColor}"    Data="M 20.4289,10.4376L 25,15.0087L 23.571,16.4376L 20.0291,12.8957L 20.0291,21.9999L 18.0083,21.9999L 18.0083,12.8583L 14.4289,16.4377L 13,15.0087L 17.5624,10.429L 19.0087,9" />-->      </Viewbox>     </Grid>     <TextBlock Grid.Column="1" x:Name="PullPart" Text="{TemplateBinding PullPartTemplate}"/>     <TextBlock Grid.Column="1" Visibility="Collapsed" x:Name="ReleasePart" Text="{TemplateBinding ReleasePartTemplate}"/>    </Grid>   </Border>   <ItemsPresenter FooterTransitions="{TemplateBinding FooterTransitions}" FooterTemplate="{TemplateBinding FooterTemplate}"     Footer="{TemplateBinding Footer}" HeaderTemplate="{TemplateBinding HeaderTemplate}" Header="{TemplateBinding Header}"     HeaderTransitions="{TemplateBinding HeaderTransitions}" Padding="{TemplateBinding Padding}" Grid.Row="1"/>  </Grid> </ScrollViewer> 

对内部的ScrollViewer的压缩进行操作,这样能够比较精准的获取用户的下拉.

同时我已经把这个代码封装成一个单独的控件,你可以从下面的链接获取到源码:

https://github.com/youngytj/uwp_PullToRefreshListview

使用方式只要在xaml里添加如下代码即可使用:

<local:PullToRefreshListView x:Name="lv"          PullPartTemplate="Pull" ReleasePartTemplate="Release"          RefreshContent="lv_RefreshContent" MoreContent="lv_MoreContent"/>

PullPartTemplate和ReleasePartTemplate分别是下拉和释放时候的文字.然后后面是更新和加载更多时候的事件.

MainPage里面通过ContentControl的来绑定内容

<ContentControl Content="{Binding CurrentViewModel}" ContentTemplate="{Binding Path=CurrentTemplate}"                              HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch"/>

View和ViewModel的绑定放在了App.xaml

<Application.Resources>  <ResourceDictionary>   <vm:ViewModelLocator x:Key="Locator"/>   <DataTemplate x:Key="HomeViewModel">    <view:HomeView/>   </DataTemplate>   ... </Application.Resources> 

这里有个注意的地方就是View只是作为一个资源的方式存在,当MainPage中发生页面转换时,会将ViewModel的名字作为一个Key(所以类名必须是Key)来寻找View.

public static class DataTemplateSelector {  public static DataTemplate GetTemplate(ViewModelBase param)  {   Type t = param.GetType();   if(!views.ContainsKey(t.Name))   {    views.Add(t.Name, App.Current.Resources[t.Name] as DataTemplate);   }   return views[t.Name];  } }