C# 如何使用Windows.Web.Http下载和存储图像？

如何使用Windows.Web.Http从internet下载jpeg图像并将其存储在Windows应用商店应用程序中

我面临的问题是，我不知道图像必须使用什么Get…Async和Write…Async方法？与字符串相比，文件是非常不同的

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仅限Windows.Web.Http

没有第三方解决方案

如果你有其他建议，请使用评论部分，而不是答案。谢谢大家!

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您可以使用该方法获取缓冲区，然后调用将缓冲区写入文件：

Uri uri = new Uri("http://i.stack.imgur.com/ZfLdV.png?s=128&g=1");
string fileName = "daniel2.png";

StorageFile destinationFile = await KnownFolders.PicturesLibrary.CreateFileAsync(
      fileName, CreationCollisionOption.GenerateUniqueName);


HttpClient client = new HttpClient();

var buffer = await client.GetBufferAsync(uri);
await Windows.Storage.FileIO.WriteBufferAsync(destinationFile, buffer);

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这与John的答案类似，但是在WP8.1中不能使用GetBufferAsync。相反，您可以按照以下方式使用GetStreamAsync：

Uri uri = new Uri(UriString);
string fileName = p4.IconLocation;

HttpClient client = new HttpClient();

var streamImage = await client.GetStreamAsync(uri);

await SaveToLocalFolderAsync(streamImage, fileName);

使用该功能：

public async Task SaveToLocalFolderAsync(Stream file, string fileName)
    {
        StorageFolder localFolder = ApplicationData.Current.LocalFolder;
        StorageFile storageFile = await localFolder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
        using (Stream outputStream = await storageFile.OpenStreamForWriteAsync())
        {
            await file.CopyToAsync(outputStream);
        }
    }

为什么不使用这个工具呢？

Uri uri = new Uri(UriString);
string fileName = p4.IconLocation;

HttpClient client = new HttpClient();

var streamImage = await client.GetStreamAsync(uri);

await SaveToLocalFolderAsync(streamImage, fileName);

public async Task SaveToLocalFolderAsync(Stream file, string fileName)
    {
        StorageFolder localFolder = ApplicationData.Current.LocalFolder;
        StorageFile storageFile = await localFolder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
        using (Stream outputStream = await storageFile.OpenStreamForWriteAsync())
        {
            await file.CopyToAsync(outputStream);
        }
    }