MemoryStream 抛出 InvalidOperationException 类型的异常

Question

希望对你有所帮助:)

在我的MVC.net core 2.2，调试的时候很简单：

MemoryStream ms = new MemoryStream();

在初始化之后它给了我一个：

ReadTimeout: 'ms.ReadTimeout' threw an exception of type 'System.InvalidOperationException'
WriteTimeout: 'ms.WriteTimeout' threw an exception of type 'System.InvalidOperationException'

现在解决方案不会崩溃或发生任何事情。但是如果我检查 Visual Studio 中的 "ms"，那就是它所说的。

我想做的是通过 SixLabors.ImageSharp 做：

IFormFile file = viewModel.File.Image;

using (Image<Rgba32> image = Image.Load(file.OpenReadStream()))
using (var ms = new MemoryStream())
{
    image.Mutate(x => x.Resize(1000, 1000));
    SixLabors.ImageSharp.Formats.Jpeg.JpegEncoder jpegEncoder = 
        new SixLabors.ImageSharp.Formats.Jpeg.JpegEncoder();
    jpegEncoder.Quality = 80;

    image.Save(ms, jpegEncoder);

    StorageCredentials storageCredentials = new StorageCredentials("Name", "KeyValue");

    // Create cloudstorage account by passing the storagecredentials
    CloudStorageAccount storageAccount = new CloudStorageAccount(storageCredentials, true);

    // Create the blob client.
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

    // Get reference to the blob container by passing the name by reading the value from the configuration (appsettings.json)
    CloudBlobContainer container = blobClient.GetContainerReference("storagefolder");

    // Get the reference to the block blob from the container
    CloudBlockBlob blockBlob = container.GetBlockBlobReference("image.jpg");

    await blockBlob.UploadFromStreamAsync(ms);
}

但是保存的stream是空的（调试时Capacity，Length，Position都有值，但是上传到azure blob storage后，大小为0）。

亲切的问候安达·亨德里克森

Answer 1

内存流的写操作不是原子的，它们被缓冲以提高效率。您需要先冲洗流。

第二个问题是，您开始将内存流复制到输出流，从流的末尾开始。所以，re-position内存流开始了。

因此，在将流写入输出之前：

ms.Flush();
ms.Position = 0; // or ms.Seek(0, SeekOrigin.Begin);

然后调用

await blockBlob.UploadFromStreamAsync(ms);

MemoryStream 抛出 InvalidOperationException 类型的异常

MemoryStream throws exception of type InvalidOperationException

c#

asp.net-mvc

memorystream

imagesharp