Flurl/Flurl.Http.PCL/DownloadExtensions.cs
2016-04-01 09:27:39 -05:00

72 lines
3.5 KiB
C#

using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;
using PCLStorage;
namespace Flurl.Http
{
public static class DownloadExtensions
{
/// <summary>
/// Asynchronously downloads a file at the specified URL.
/// </summary>
/// <param name="localFolderPath">Path of local folder where file is to be downloaded.</param>
/// <param name="localFileName">Name of local file. If not specified, the source filename (last segment of the URL) is used.</param>
/// <param name="bufferSize">Buffer size in bytes. Default is 4096.</param>
/// <returns>A Task whose result is the local path of the downloaded file.</returns>
public static async Task<string> DownloadFileAsync(this FlurlClient client, string localFolderPath, string localFileName = null, int bufferSize = 4096) {
if (localFileName == null)
localFileName = client.Url.Path.Split('/').Last();
var folder = await EnsureFolderAsync(localFolderPath).ConfigureAwait(false);
var file = await folder.CreateFileAsync(localFileName, CreationCollisionOption.ReplaceExisting).ConfigureAwait(false);
// need to temporarily disable autodispose if set, otherwise reading from stream will fail
var autoDispose = client.AutoDispose;
client.AutoDispose = false;
try {
var response = await client.SendAsync(HttpMethod.Get, completionOption: HttpCompletionOption.ResponseHeadersRead).ConfigureAwait(false);
// http://codereview.stackexchange.com/a/18679
using (var httpStream = await response.Content.ReadAsStreamAsync().ConfigureAwait(false))
using (var filestream = await file.OpenAsync(FileAccess.ReadAndWrite).ConfigureAwait(false)) {
await httpStream.CopyToAsync(filestream, bufferSize).ConfigureAwait(false);
}
return PortablePath.Combine(localFolderPath, localFileName);
}
finally {
client.AutoDispose = autoDispose;
if (client.AutoDispose) client.Dispose();
}
}
/// <summary>
/// Asynchronously downloads a file at the specified URL.
/// </summary>
/// <param name="localFolderPath">Path of local folder where file is to be downloaded.</param>
/// <param name="localFileName">Name of local file. If not specified, the source filename (last segment of the URL) is used.</param>
/// <param name="bufferSize">Buffer size in bytes. Default is 4096.</param>
/// <returns>A Task whose result is the local path of the downloaded file.</returns>
public static Task<string> DownloadFileAsync(this string url, string localFolderPath, string localFileName = null, int bufferSize = 4096) {
return new FlurlClient(url, true).DownloadFileAsync(localFolderPath, localFileName, bufferSize);
}
/// <summary>
/// Asynchronously downloads a file at the specified URL.
/// </summary>
/// <param name="localFolderPath">Path of local folder where file is to be downloaded.</param>
/// <param name="localFileName">Name of local file. If not specified, the source filename (last segment of the URL) is used.</param>
/// <param name="bufferSize">Buffer size in bytes. Default is 4096.</param>
/// <returns>A Task whose result is the local path of the downloaded file.</returns>
public static Task<string> DownloadFileAsync(this Url url, string localFolderPath, string localFileName = null, int bufferSize = 4096) {
return new FlurlClient(url, true).DownloadFileAsync(localFolderPath, localFileName, bufferSize);
}
private static Task<IFolder> EnsureFolderAsync(string path) {
return FileSystem.Current.LocalStorage.CreateFolderAsync(path, CreationCollisionOption.OpenIfExists);
}
}
}