与众不同 windows phone (13) - Background Task(后台任务)之后台文件传输(上传和下载)
与众不同 windows phone (13) - Background Task(后台任务)之后台文件传输(上传和下载)
作者:webabcd
介绍
与众不同 windows phone 7.5 (sdk 7.1) 之后台任务
- 后台文件传输(下载)
- 后台文件传输(上传)
示例
1、演示如何实现后台文件传输(下载)
BackgroundTransferDownload.xaml
<phone:PhoneApplicationPage x:Class="Demo.BackgroundTask.BackgroundTransferDownload" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone" xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" FontFamily="{StaticResource PhoneFontFamilyNormal}" FontSize="{StaticResource PhoneFontSizeNormal}" Foreground="{StaticResource PhoneForegroundBrush}" SupportedOrientations="Portrait" Orientation="Portrait" mc:Ignorable="d" d:DesignHeight="768" d:DesignWidth="480" shell:SystemTray.IsVisible="True"> <Grid x:Name="LayoutRoot" Background="Transparent"> <StackPanel Orientation="Vertical"> <Button x:Name="btnDownloadSilverlightDemo" Content="下载 Silverlight Demo 压缩包" Click="btnDownloadSilverlightDemo_Click" /> <Button x:Name="btnDownloadXNADemo" Content="下载 XNA Demo 压缩包" Click="btnDownloadXNADemo_Click" /> <Button x:Name="btnDownloadWindowsPhoneDemo" Content="下载 WindowsPhone Demo 压缩包" Click="btnDownloadWindowsPhoneDemo_Click" /> <TextBlock Text="下载任务列表:" Margin="0 15 0 0" /> <ListBox Name="listBox"> <ListBox.ItemTemplate> <DataTemplate> <Grid Margin="0 15" Width="480"> <Grid.ColumnDefinitions> <ColumnDefinition Width="8*"/> <ColumnDefinition Width="2*"/> </Grid.ColumnDefinitions> <Grid> <StackPanel Orientation="Vertical"> <StackPanel Orientation="Horizontal"> <TextBlock Text="文件名: "/> <TextBlock Text="{Binding Tag}"/> </StackPanel> <StackPanel Orientation="Horizontal"> <TextBlock Text="下载状态: "/> <TextBlock Text="{Binding TransferStatus}" /> </StackPanel> <StackPanel Orientation="Horizontal"> <TextBlock Text="已接收字节数: "/> <TextBlock Text="{Binding BytesReceived}" /> </StackPanel> <StackPanel Orientation="Horizontal"> <TextBlock Text="总共字节数: "/> <TextBlock Text="{Binding TotalBytesToReceive}" /> </StackPanel> </StackPanel> </Grid> <Grid Grid.Column="1"> <Button x:Name="btnCancel" Tag="{Binding RequestId}" Click="btnCancel_Click" Content="删除任务"></Button> </Grid> </Grid> </DataTemplate> </ListBox.ItemTemplate> </ListBox> </StackPanel> </Grid> </phone:PhoneApplicationPage>
BackgroundTransferDownload.xaml.cs
/* * 演示如何实现后台文件传输(下载) * * * BackgroundTransferRequest - 后台文件传输请求 * BackgroundTransferRequest(Uri) - 构造函数。参数解释:下载时其为需要下载的文件的远程地址;上传时其为接收文件的远程服务地址 * RequestId - 后台文件传输请求的唯一 ID,只读 * RequestUri - 请求的地址,只读。其需要在构造函数中设置 * Method - 请求的 http 方法,GET - 下载;POST - 上传 * Headers - 请求的 http 头,有一些头信息不能自定义,如 Range 等 * StatusCode - http 请求回应的状态码 * Tag - 自定义此对象的关联信息,即上下文数据 * TransferPreferences - 传输的启动条件(Microsoft.Phone.BackgroundTransfer.TransferPreferences 枚举) * None - 仅在外部电源 + WiFi 环境下允许传输 * AllowCellular - 允许在手机网络环境下传输 * AllowBattery - 允许在电池做电源的环境下传输 * AllowCellularAndBattery - 允许在电池电源 + 手机网络的环境下传输 * TransferError - 错误信息 * TransferStatus - 传输状态(Microsoft.Phone.BackgroundTransfer.TransferStatus 枚举) * None - 传输任务尚未加入到传输队列 * Waiting - 在传输队列,等待传输 * Transferring - 传输中 * Paused - 暂停 * Completed - 传输任务已完成,如果传输成功则 TransferError 为 null * WaitingForWiFi - WiFi 网络 * WaitingForExternalPower - 需要接上外接电源 * WaitingForExternalPowerDueToBatterySaverMode - 需要接上外接电源,或者禁用节电模式 * WaitingForNonVoiceBlockingNetwork - 不能使用无法和语音并发的网络(如 2G、EDGE 和标准 GPRS) * DownloadLocation - 下载到的目标位置 * UploadLocation - 需要上传的文件的地址 * BytesReceived - 文件已下载的字节数 * BytesSent - 文件已上传的字节数 * TotalBytesToReceive - 需要下载的文件的总字节数(-1 则文件大小未知) * TotalBytesToSend - 需要上传的文件的总字节数(-1 则文件大小未知) * * TransferProgressChanged - 传输进度改变时所触发的事件 * TransferStatusChanged - 属性 TransferStatus 发生改变时所触发的事件 * * * BackgroundTransferService - 对后台文件传输请求的管理 * Add() - 添加一个 BackgroundTransferRequest * Find() - 通过 RequestId 查找指定的 BackgroundTransferRequest * Remove - 通过 RequestId 删除指定的 BackgroundTransferRequest * * * 注意: * 后台文件传输既支持 http 又支持 https * 传输的文件必须在 /shared/transfers 目录下 * 上传文件最大 5 MB,手机网络下载文件最大 20 MB,WiFi+电池电源下载文件最大 100 MB,WiFi+外接电源下载文件则允许大于 100 MB * 下载文件超过 5 MB 时,系统会向服务端发 Range 头分段下载(不会多线程下载,但是会断点续传) * 每个应用程序的传输任务队列,最大支持 5 个任务,设备支持 500 个任务 * 设备上最大并发传输数为 2 个 */ using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using Microsoft.Phone.Controls; using Microsoft.Phone.BackgroundTransfer; using System.IO.IsolatedStorage; namespace Demo.BackgroundTask { public partial class BackgroundTransferDownload : PhoneApplicationPage { public BackgroundTransferDownload() { InitializeComponent(); } protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e) { // 为每个 BackgroundTransferRequest 注册相关事件 foreach (var transfer in BackgroundTransferService.Requests) { transfer.TransferStatusChanged += new EventHandler<BackgroundTransferEventArgs>(transfer_TransferStatusChanged); transfer.TransferProgressChanged += new EventHandler<BackgroundTransferEventArgs>(transfer_TransferProgressChanged); } UpdateUI(); } private void ProcessTransfer(BackgroundTransferRequest transfer) { switch (transfer.TransferStatus) { case TransferStatus.Completed: // 200 - 下载完成;206 - 分块下载完成 if (transfer.StatusCode == 200 || transfer.StatusCode == 206) { // 下载完成后不会自动从队列中删除,需要手动删除 RemoveTransferRequest(transfer.RequestId); // 将下载完成后的文件移动到独立存储的根目录下 using (IsolatedStorageFile isoStore = IsolatedStorageFile.GetUserStoreForApplication()) { string filename = transfer.Tag; if (isoStore.FileExists(filename)) { isoStore.DeleteFile(filename); } isoStore.MoveFile(transfer.DownloadLocation.OriginalString, filename); } } else { // 如果回应的不是 200 或 206 则意味着出现了问题 // 将任务其移出队列 RemoveTransferRequest(transfer.RequestId); // 发生了异常,做一些相关处理 if (transfer.TransferError != null) { MessageBox.Show(transfer.TransferError.ToString()); } } break; // 注:以下 4 个状态最好做一下判断和处理,然后呈现给用户 case TransferStatus.WaitingForExternalPower: break; case TransferStatus.WaitingForExternalPowerDueToBatterySaverMode: break; case TransferStatus.WaitingForNonVoiceBlockingNetwork: break; case TransferStatus.WaitingForWiFi: break; } } void transfer_TransferStatusChanged(object sender, BackgroundTransferEventArgs e) { ProcessTransfer(e.Request); UpdateUI(); } void transfer_TransferProgressChanged(object sender, BackgroundTransferEventArgs e) { UpdateUI(); } private void btnCancel_Click(object sender, EventArgs e) { string transferId = ((Button)sender).Tag as string; RemoveTransferRequest(transferId); UpdateUI(); } // 从 BackgroundTransferService 中删除指定的传输请求 private void RemoveTransferRequest(string transferId) { BackgroundTransferRequest transfer = BackgroundTransferService.Find(transferId); try { if (transfer != null) BackgroundTransferService.Remove(transfer); } catch (Exception ex) { MessageBox.Show("RemoveTransferRequest: " + ex.ToString()); } } private void UpdateUI() { // 更新 UI listBox.ItemsSource = BackgroundTransferService.Requests; } private void btnDownloadSilverlightDemo_Click(object sender, RoutedEventArgs e) { // 如果 url 中有特殊字符,如汉字等,建议使用 Uri.EscapeUriString 编码 AddBackgroundTransfer("Silverlight.rar", new Uri("https://files.cnblogs.com/webabcd/Silverlight.rar", UriKind.Absolute)); UpdateUI(); } private void btnDownloadXNADemo_Click(object sender, RoutedEventArgs e) { AddBackgroundTransfer("XNA.rar", new Uri("https://files.cnblogs.com/webabcd/XNA.rar", UriKind.Absolute)); UpdateUI(); } private void btnDownloadWindowsPhoneDemo_Click(object sender, RoutedEventArgs e) { AddBackgroundTransfer("WindowsPhone.rar", new Uri("https://files.cnblogs.com/webabcd/WindowsPhone.rar", UriKind.Absolute)); UpdateUI(); } /// <summary> /// 添加后台传输任务到队列 /// </summary> /// <param name="fileName">需要在本地保存的文件名</param> /// <param name="fileUri">需要下载的文件的远程地址</param> private void AddBackgroundTransfer(string fileName, Uri fileUri) { // 做一下相关判断 if (BackgroundTransferService.Requests.Count() >= 5) { MessageBox.Show("每个应用程序的后台传输队列最多只能有 5 个任务"); return; } if (BackgroundTransferService.Requests.Any(p => p.RequestUri == fileUri)) { MessageBox.Show("任务已在队列中"); return; } BackgroundTransferRequest transferRequest = new BackgroundTransferRequest(fileUri); transferRequest.Method = "GET"; // 下载 transferRequest.TransferPreferences = TransferPreferences.None; // 仅在外部电源 + WiFi 环境下允许下载 transferRequest.TransferStatusChanged += new EventHandler<BackgroundTransferEventArgs>(transfer_TransferStatusChanged); transferRequest.TransferProgressChanged += new EventHandler<BackgroundTransferEventArgs>(transfer_TransferProgressChanged); transferRequest.Tag = fileName; // 给 TransferRequest 赋值一个上下文数据 transferRequest.DownloadLocation = new Uri("shared/transfers/" + fileName, UriKind.Relative); try { BackgroundTransferService.Add(transferRequest); } catch (Exception ex) { MessageBox.Show("AddBackgroundTransfer: " + ex.ToString()); } } } }
2、演示如何实现后台文件传输(上传)
BackgroundTransferUpload.xaml
<phone:PhoneApplicationPage x:Class="Demo.BackgroundTask.BackgroundTransferUpload" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone" xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" FontFamily="{StaticResource PhoneFontFamilyNormal}" FontSize="{StaticResource PhoneFontSizeNormal}" Foreground="{StaticResource PhoneForegroundBrush}" SupportedOrientations="Portrait" Orientation="Portrait" mc:Ignorable="d" d:DesignHeight="768" d:DesignWidth="480" shell:SystemTray.IsVisible="True"> <Grid x:Name="LayoutRoot" Background="Transparent"> <StackPanel Orientation="Vertical"> <Button x:Name="btnUpload" Content="上传 Demo.mp4 文件到服务端" Click="btnUpload_Click" /> </StackPanel> </Grid> </phone:PhoneApplicationPage>
BackgroundTransferUpload.xaml.cs
/* * 演示如何实现后台文件传输(上传) * * BackgroundTransferRequest、BackgroundTransferService 及相关注意事项详见:BackgroundTask/BackgroundTransferDownload.xaml.cs */ using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using Microsoft.Phone.Controls; using Microsoft.Phone.BackgroundTransfer; using System.IO.IsolatedStorage; using System.Windows.Resources; using System.IO; namespace Demo.BackgroundTask { public partial class BackgroundTransferUpload : PhoneApplicationPage { public BackgroundTransferUpload() { InitializeComponent(); } protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e) { // 为每个 BackgroundTransferRequest 注册相关事件 foreach (var transfer in BackgroundTransferService.Requests) { transfer.TransferStatusChanged += new EventHandler<BackgroundTransferEventArgs>(transfer_TransferStatusChanged); transfer.TransferProgressChanged += new EventHandler<BackgroundTransferEventArgs>(transfer_TransferProgressChanged); } } private void ProcessTransfer(BackgroundTransferRequest transfer) { switch (transfer.TransferStatus) { case TransferStatus.Completed: // 200 代表上传成功 if (transfer.StatusCode == 200) { MessageBox.Show("上传成功"); } else { // 发生了异常,做一些相关处理 if (transfer.TransferError != null) { MessageBox.Show(transfer.TransferError.ToString()); } } RemoveTransferRequest(transfer.RequestId); break; // 注:以下 4 个状态最好做一下判断和处理,然后呈现给用户 case TransferStatus.WaitingForExternalPower: break; case TransferStatus.WaitingForExternalPowerDueToBatterySaverMode: break; case TransferStatus.WaitingForNonVoiceBlockingNetwork: break; case TransferStatus.WaitingForWiFi: break; } } void transfer_TransferStatusChanged(object sender, BackgroundTransferEventArgs e) { ProcessTransfer(e.Request); } void transfer_TransferProgressChanged(object sender, BackgroundTransferEventArgs e) { // 上传进度发生改变 } private void btnCancel_Click(object sender, EventArgs e) { string transferId = ((Button)sender).Tag as string; RemoveTransferRequest(transferId); } // 从 BackgroundTransferService 中删除指定的传输请求 private void RemoveTransferRequest(string transferId) { BackgroundTransferRequest transfer = BackgroundTransferService.Find(transferId); try { if (transfer != null) BackgroundTransferService.Remove(transfer); } catch (Exception ex) { MessageBox.Show("RemoveTransferRequest: " + ex.ToString()); } } private void btnUpload_Click(object sender, RoutedEventArgs e) { // 将 Demo.mp4 文件从程序包复制到独立存储的 shared/transfers 目录,以备上传 StreamResourceInfo sr = Application.GetResourceStream(new Uri("Assets/Demo.mp4", UriKind.Relative)); using (BinaryReader br = new BinaryReader(sr.Stream)) { byte[] data = br.ReadBytes((int)sr.Stream.Length); IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication(); using (var isfs = new IsolatedStorageFileStream(@"shared/transfers/Demo.mp4", FileMode.Create, isf)) { using (var bw = new BinaryWriter(isfs)) { bw.Write(data); } } } AddBackgroundTransfer("Demo.mp4", new Uri(@"shared/transfers/Demo.mp4", UriKind.Relative)); } /// <summary> /// 添加后台传输任务到队列 /// </summary> /// <param name="fileName">需要在服务端保存的文件名</param> /// <param name="fileUri">需要上传的文件的本地地址</param> private void AddBackgroundTransfer(string fileName, Uri fileUri) { BackgroundTransferRequest transferRequest = new BackgroundTransferRequest(new Uri("http://localhost:15482/UploadFile.aspx?fileName=" + fileName, UriKind.Absolute)); transferRequest.Method = "POST"; // 上传 transferRequest.TransferPreferences = TransferPreferences.None; // 仅在外部电源 + WiFi 环境下允许上传 transferRequest.TransferStatusChanged += new EventHandler<BackgroundTransferEventArgs>(transfer_TransferStatusChanged); transferRequest.TransferProgressChanged += new EventHandler<BackgroundTransferEventArgs>(transfer_TransferProgressChanged); transferRequest.UploadLocation = fileUri; try { BackgroundTransferService.Add(transferRequest); } catch (Exception ex) { MessageBox.Show("AddBackgroundTransfer: " + ex.ToString()); } } } }
UploadFile.aspx.cs(用于保存上传文件的服务端代码)
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.IO; namespace Web { public partial class UploadFile : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (Request.TotalBytes > 0) { // 保存上传过来的文件 byte[] data = Request.BinaryRead(Request.TotalBytes); File.WriteAllBytes(@"C:\" + Request.QueryString["fileName"], data); } } } }
OK
[源码下载]