/// <summary>
/// 保存远程url地址图片,到本地
/// </summary>
/// <param name="uri">远程地址</param>
/// <param name="filename">保存的名称</param>
/// <param name="folder">保存位置枚举</param>
/// <returns></returns>
internal async static Task SaveImageFromUrl(string uri, string filename, StorageFolder folder)
{
var rass = RandomAccessStreamReference.CreateFromUri(new Uri(uri));
IRandomAccessStream inputStream = await rass.OpenReadAsync();
Stream input = WindowsRuntimeStreamExtensions.AsStreamForRead(inputStream.GetInputStreamAt(0));
try
{
//获取图片扩展名的Guid
StorageFile outputFile = await folder.CreateFileAsync(filename, CreationCollisionOption.ReplaceExisting);
using (IRandomAccessStream outputStream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
Stream output = WindowsRuntimeStreamExtensions.AsStreamForWrite(outputStream.GetOutputStreamAt(0));
await input.CopyToAsync(output);
output.Dispose();
input.Dispose();
}
}
catch (Exception ex)
{
throw ex;
}
}
/// <summary>
/// 流转换成本地图片
/// </summary>
/// <param name="inputstream"></param>
/// <param name="filename"></param>
/// <returns></returns>
internal async static Task StreamToFileName(Stream inputstream, string filename)
{
try
{
StorageFolder folder = KnownFolders.SavedPictures;
StorageFile outputFile = await folder.CreateFileAsync(filename, CreationCollisionOption.ReplaceExisting);
using (IRandomAccessStream output = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
{
Stream outputstream = WindowsRuntimeStreamExtensions.AsStreamForWrite(output.GetOutputStreamAt(0));
await inputstream.CopyToAsync(outputstream);
outputstream.Dispose();
inputstream.Dispose();
}
}
catch (Exception ex)
{
throw ex;
}
}
public static Stream OpenFileForWriting(string uri)
{
string fileName = Path.GetFileName(uri);
Task <StorageFile> task1 = WindowsRuntimeSystemExtensions.AsTask <StorageFile>(FileHelper.GetFolderForPathOrURI(uri).CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting));
task1.Wait();
if (task1.Status != TaskStatus.RanToCompletion)
{
throw new Exception("Failed to open the file");
}
Task <IRandomAccessStream> task2 = WindowsRuntimeSystemExtensions.AsTask <IRandomAccessStream>(task1.Result.OpenAsync(FileAccessMode.ReadWrite));
task2.Wait();
if (task2.Status != TaskStatus.RanToCompletion)
{
throw new Exception("Failed to open the file");
}
else
{
return(WindowsRuntimeStreamExtensions.AsStreamForWrite((IOutputStream)task2.Result));
}
}