Question

我无法使用DownloadDataAsync方法。唯一存在的选项是DownloadStringAsync方法。如何使用此方法下载zip文件。（我是windows phone 8 app开发的新手）

Answer 1

我只想分享对我有用的解决方案。我创建了一个web请求给了url并将gzip文件下载到了独立的存储文件中。现在下载后我创建了一个目标文件流，并使用GZipStream的WriteByte方法将压缩的gzip流文件从源文件存储到目标文件。现在我们得到未压缩的文件。

注意：-GZipStream可以从NuGet管理器添加到Visual Studio。

以下是我用来下载和提取GZip文件的代码段。

public async Task DownloadZipFile（Uri fileAdress，string fileName） { 尝试 {

            WebRequest request = WebRequest.Create(fileAdress);
            if (request != null)
            {
                WebResponse webResponse = await request.GetResponseAsync();
                if (webResponse.ContentLength != 0)
                {
                    using (Stream response = webResponse.GetResponseStream())
                    {
                        if (response.Length != 0)
                        {
                            using (IsolatedStorageFile isolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
                            {
                                if (isolatedStorage.FileExists(fileName))
                                    isolatedStorage.DeleteFile(fileName);
                                using (IsolatedStorageFileStream file = isolatedStorage.CreateFile(fileName))
                                {
                                    const int BUFFER_SIZE = 100 * 1024;
                                    byte[] buf = new byte[BUFFER_SIZE];
                                    int bytesread;
                                    while ((bytesread = await response.ReadAsync(buf, 0, BUFFER_SIZE)) > 0)
                                    {
                                        file.Write(buf, 0, bytesread);
                                    }
                                    file.Close();

                                    FileStream sourceFileStream = File.OpenRead(file.Name);
                                    FileStream destFileStream = File.Create(AppResources.OpenZipFileName);

                                    GZipStream decompressingStream = new GZipStream(sourceFileStream, CompressionMode.Decompress);
                                    int byteRead;
                                    while ((byteRead = decompressingStream.ReadByte()) != -1)
                                    {
                                        destFileStream.WriteByte((byte)byteRead);
                                    }
                                    decompressingStream.Close();
                                    sourceFileStream.Close();
                                    destFileStream.Close();
                                    PhoneApplicationService.Current.State["DestinationFilePath"] = destFileStream.Name;
                                }
                            }
                            FileDownload = true;
                        }
                    }
                }
            }

            if (FileDownload == true)
            {
                return DownloadStatus.Ok;
            }
            else
            {
                return DownloadStatus.Other;
            }
        }

        catch (Exception exc)
        {
            return DownloadStatus.Other;
        }

    }

Answer 2

您必须使用DownloadStrringAsync方法吗？否则你可以查看这些：

How to extract zipped file received from HttpWebResponse?

download and decompress a zip file in windows phone 8 application

Extract zip file from isolatedstorage

How to download a GZIP file from web to Windows Phone 7 and unzip the contents

Answer 3

要首先从网址下载zip文件，需要将zip文件存储到独立存储中，之后将其解压缩并根据需要读取文件。

http://axilis.hr/uznip-archives-windows-phone

如何从URL下载zip文件并在Windows Phone 8上解压缩.zip文件包含来自服务器的压缩sqlite文件

3 个答案: