Try seek blob stream position to begin

framework/src/Volo.Abp.BlobStoring.Aliyun/Volo/Abp/BlobStoring/Aliyun/AliyunBlobProvider.cs

@@ -86,9 +86,7 @@ public override async Task<Stream> GetOrNullAsync(BlobProviderGetArgs args)
                 return null;
             }
             var result = ossClient.GetObject(containerName, blobName);
-            var memoryStream = new MemoryStream();
-            await result.Content.CopyToAsync(memoryStream);
-            return memoryStream;
+            return await TryCopyToMemoryStreamAsync(result.Content, args.CancellationToken);
         }
 
         protected virtual string GetContainerName(BlobProviderArgs args)

framework/src/Volo.Abp.BlobStoring.Aws/Volo/Abp/BlobStoring/Aws/AwsBlobProvider.cs

@@ -103,9 +103,7 @@ public override async Task<Stream> GetOrNullAsync(BlobProviderGetArgs args)
                     Key = blobName
                 });
 
-                var memoryStream = new MemoryStream();
-                await response.ResponseStream.CopyToAsync(memoryStream);
-                return memoryStream;
+                return await TryCopyToMemoryStreamAsync(response.ResponseStream, args.CancellationToken);
             }
         }
 

framework/src/Volo.Abp.BlobStoring.Azure/Volo/Abp/BlobStoring/Azure/AzureBlobProvider.cs

@@ -67,9 +67,7 @@ public override async Task<Stream> GetOrNullAsync(BlobProviderGetArgs args)
 
             var blobClient = GetBlobClient(args, blobName);
             var download = await blobClient.DownloadAsync();
-            var memoryStream = new MemoryStream();
-            await download.Value.Content.CopyToAsync(memoryStream);
-            return memoryStream;
+            return await TryCopyToMemoryStreamAsync(download.Value.Content, args.CancellationToken);
         }
 
         protected virtual BlobClient GetBlobClient(BlobProviderArgs args, string blobName)

framework/src/Volo.Abp.BlobStoring.FileSystem/Volo/Abp/BlobStoring/FileSystem/FileSystemBlobProvider.cs

@@ -74,9 +74,7 @@ public override async Task<Stream> GetOrNullAsync(BlobProviderGetArgs args)
                 {
                     using (var fileStream = File.OpenRead(filePath))
                     {
-                        var memoryStream = new MemoryStream();
-                        await fileStream.CopyToAsync(memoryStream, args.CancellationToken);
-                        return memoryStream;
+                        return await TryCopyToMemoryStreamAsync(fileStream, args.CancellationToken);
                     }
                 });
         }

framework/src/Volo.Abp.BlobStoring.Minio/Volo/Abp/BlobStoring/Minio/MinioBlobProvider.cs

@@ -75,20 +75,13 @@ public override async Task<Stream> GetOrNullAsync(BlobProviderGetArgs args)
                 return null;
             }
 
-            var memoryStream = new MemoryStream();
+            Stream blobStream = null;
             await client.GetObjectAsync(containerName, blobName,  (stream) =>
             {
-                    if (stream != null)
-                    {
-                        stream.CopyTo(memoryStream);
-                    }
-                    else
-                    {
-                        memoryStream = null;
-                    }
+                blobStream = stream;
             });
 
-            return memoryStream;
+            return await TryCopyToMemoryStreamAsync(blobStream, args.CancellationToken);
         }
 
         protected virtual MinioClient GetMinioClient(BlobProviderArgs args)

framework/src/Volo.Abp.BlobStoring/Volo/Abp/BlobStoring/BlobProviderBase.cs

@@ -1,4 +1,5 @@
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Volo.Abp.BlobStoring
@@ -12,5 +13,18 @@ public abstract class BlobProviderBase : IBlobProvider
         public abstract Task<bool> ExistsAsync(BlobProviderExistsArgs args);
 
         public abstract Task<Stream> GetOrNullAsync(BlobProviderGetArgs args);
+
+        protected virtual async Task<Stream> TryCopyToMemoryStreamAsync(Stream stream, CancellationToken cancellationToken = default)
+        {
+            if(stream == null)
+            {
+                return null;
+            }
+
+            var memoryStream = new MemoryStream();
+            await stream.CopyToAsync(memoryStream, cancellationToken);
+            memoryStream.Seek(0, SeekOrigin.Begin);
+            return memoryStream;
+        }
     }
 }