uwp 下载文件显示进度并解压文件

uwp 下载文件显示进度并解压文件。

<Page
    x:Class="App4.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:App4"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" Width="909" Height="429">
    <Grid >

        <Grid Name="gridPercent" VerticalAlignment="Top" Height="57" Margin="183,0,0,0">
            <Rectangle Name="lbPercent"  VerticalAlignment="Top" Height="53" Margin="0" HorizontalAlignment="Left" Width="0" Fill="Blue"/>
        </Grid>
        <TextBlock Name="txt" Foreground="Red" Text="0%"  VerticalAlignment="Top" Height="53" Margin="200,0,7,0" HorizontalAlignment="Stretch"/>

        <Button x:Name="btnDownload" Background="WhiteSmoke" HorizontalAlignment="Left" Height="57" VerticalAlignment="Top" Width="178" Content="download" Click="BtnDownload_Click"  />

    </Grid>
</Page>

　　

using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using System.Threading.Tasks;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Graphics.Imaging;
using Windows.Storage;
using Windows.Storage.Streams;
using Windows.UI;
using Windows.UI.Popups;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Imaging;
using Windows.UI.Xaml.Navigation;

// The Blank Page item template is documented at https://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x409

namespace App4
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();
            Loaded += MainPage_Loaded;

        }
        private bool isDownloading = false;

        private async void MainPage_Loaded(object sender, RoutedEventArgs e)
        {

        }

        private void BtnDownload_Click(object sender, RoutedEventArgs e)
        {
            dowloadFile();
        }

        async void dowloadFile()
        {

            if (isDownloading) return;

            isDownloading = true;
            string serverUrl = "http://files.cnblogs.com/files/pcat/hackbar.zip";//"https://files.cnblogs.com/files/wgscd/jyzsUpdate.zip";
            bool isDownloadComplete = false;
            try
            {
                System.Net.HttpWebRequest request = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(serverUrl);
                System.Net.WebResponse response = await request.GetResponseAsync();

                System.IO.Stream ns = response.GetResponseStream();
                long totalSize = response.ContentLength;
                double hasDownSize = 0;
                byte[] nbytes = new byte[512];//521,2048 etc
                int nReadSize = 0;
                nReadSize = ns.Read(nbytes, 0, nbytes.Length);
                StorageFolder folder;
                folder = ApplicationData.Current.LocalFolder;
                string localFile = "test.zip";
                StorageFile file = await folder.CreateFileAsync(localFile, CreationCollisionOption.ReplaceExisting);

                using (StorageStreamTransaction transaction = await file.OpenTransactedWriteAsync())
                {
                    using (DataWriter dataWriter = new DataWriter(transaction.Stream))
                    {
                        while (nReadSize > 0)
                        {

                            dataWriter.WriteBytes(nbytes);

                            nReadSize = ns.Read(nbytes, 0, 512);
                            hasDownSize += nReadSize;
                            this.Invoke(new Action(() =>
                            {
                                txt.Text = "" + (hasDownSize / 1024.0).ToString("0.00") + " KB/" + (totalSize / 1024.0).ToString("0.00") + " KB   (" + (((double)hasDownSize * 100 / totalSize).ToString("0")) + "%)";//显示下载百分比
                                lbPercent.Width = gridPercent.RenderSize.Width * ((double)hasDownSize / totalSize);
                                txt.UpdateLayout();
                            }));

                        }

                        transaction.Stream.Size = await dataWriter.StoreAsync();
                        await dataWriter.FlushAsync();
                        await transaction.CommitAsync();
                        isDownloadComplete = true;
                        this.Invoke(new Action(() =>
                        {
                            txt.Text = "100%";//显示下载百分比
                            txt.UpdateLayout();
                        }));
                        await new MessageDialog("download complete!").ShowAsync();
                        UnzipFile(localFile);
                    }
                }

            }
            catch (Exception ex)
            {
                await new MessageDialog("download error:" + ex.ToString()).ShowAsync();
            }
            isDownloading = false;
        }

        public async void Invoke(Action action, Windows.UI.Core.CoreDispatcherPriority Priority = Windows.UI.Core.CoreDispatcherPriority.Normal)
        {

            await Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(Priority, () => { action(); });

        }

        private async void UnzipFile(string zipFileName)
        {

            Random rnd = new Random();

            string existfile = "Elasticsearch.pptx";
            var localFolder = ApplicationData.Current.LocalFolder; //路径形如：C:\Users\gwang\AppData\Local\Packages\347b02f6-8bb6-4c2c-a494-82f3fb42f42a_px2gx6zt1mshw\LocalState

            //尝试删除旧文件
            var oldFile = await ApplicationData.Current.LocalFolder.TryGetItemAsync(existfile);
            if (oldFile != null)
            {
                var file = await localFolder.GetFileAsync(existfile);
                await file.DeleteAsync();
            }
            //开始解压
            var archive = await localFolder.GetFileAsync(zipFileName);//eg test.zip
            ZipFile.ExtractToDirectory(archive.Path, localFolder.Path + "\\" + rnd.Next(1, 20000));//如果目标文件存在会异常
            await new MessageDialog("unzip done!").ShowAsync();

        }

        /// <summary>
        /// another sample, not know how to show download processs
        /// </summary>
        async void downloadFileUseHttpClient()
        {

            string serverUrl = "http://files.cnblogs.com/files/pcat/hackbar.zip";
            System.Net.Http.HttpClientHandler hand = new System.Net.Http.HttpClientHandler();
            //  System.Net.Http.MessageProcessingHandler processMessageHander = new System.Net.Http.MessageProcessingHandler();
            System.Net.Http.HttpClient localHttpClient = new System.Net.Http.HttpClient();
            System.Net.Http.HttpRequestMessage httpRequestMessage = new System.Net.Http.HttpRequestMessage(System.Net.Http.HttpMethod.Post, serverUrl);
            var resp = await localHttpClient.SendAsync(httpRequestMessage);
            Stream stream = await resp.Content.ReadAsStreamAsync();
            //............

        }

    }
}

　　

另外一种方法是利用：System.Net.Http.HttpClient

  /// <summary>
        /// another sampe
        /// </summary>
        async void downloadFileUseHttpClient()
        {

            string serverUrl = "http://files.cnblogs.com/files/pcat/hackbar.zip";
            System.Net.Http.HttpClient localHttpClient = new System.Net.Http.HttpClient();
            var progress = new Progress<HttpDownloadProgress>(percent => {
                    txt.Text =""+ percent.BytesReceived+"/"+percent.TotalBytesToReceive;
                    txt.UpdateLayout();
                });

            CancellationToken token=new CancellationToken();
            var data= await  HttpClientExtensions.GetByteArrayAsync(localHttpClient, new Uri(serverUrl), progress, token);
            var folder = ApplicationData.Current.LocalFolder;
            string localFile = "test.zip";
            StorageFile file = await folder.CreateFileAsync(localFile, CreationCollisionOption.ReplaceExisting);
            using (StorageStreamTransaction transaction = await file.OpenTransactedWriteAsync())
            {
                using (DataWriter dataWriter = new DataWriter(transaction.Stream))
                {
                    dataWriter.WriteBytes(data.ToArray());
                    transaction.Stream.Size = await dataWriter.StoreAsync();
                    await dataWriter.FlushAsync();
                    await transaction.CommitAsync();
                }

            }

        }

    public static class HttpClientExtensions
    {
        private const int BufferSize = 8192;

        public static async Task<byte[]> GetByteArrayAsync(this HttpClient client, Uri requestUri, IProgress<HttpDownloadProgress> progress, CancellationToken cancellationToken)
        {
            if (client == null)
            {
                throw new ArgumentNullException(nameof(client));
            }

            using (var responseMessage = await client.GetAsync(requestUri, HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false))
            {
                responseMessage.EnsureSuccessStatusCode();

                var content = responseMessage.Content;
                if (content == null)
                {
                    return Array.Empty<byte>();
                }

                var headers = content.Headers;
                var contentLength = headers.ContentLength;
                using (var responseStream = await content.ReadAsStreamAsync().ConfigureAwait(false))
                {
                    var buffer = new byte[BufferSize];
                    int bytesRead;
                    var bytes = new List<byte>();

                    var downloadProgress = new HttpDownloadProgress();
                    if (contentLength.HasValue)
                    {
                        downloadProgress.TotalBytesToReceive = (ulong)contentLength.Value;
                    }
                    progress?.Report(downloadProgress);

                    while ((bytesRead = await responseStream.ReadAsync(buffer, 0, BufferSize, cancellationToken).ConfigureAwait(false)) > 0)
                    {
                        bytes.AddRange(buffer.Take(bytesRead));

                        downloadProgress.BytesReceived += (ulong)bytesRead;
                        progress?.Report(downloadProgress);
                    }

                    return bytes.ToArray();
                }
            }
        }

    public struct HttpDownloadProgress
    {
        public ulong BytesReceived { get; set; }

        public ulong? TotalBytesToReceive { get; set; }
    }