文件下载进度逻辑优化

Author: xljiulang

WebApiClient/HttpResponseFile.cs

@@ -90,26 +90,31 @@ public async Task SaveAsAsync(Stream stream)
                 throw new ArgumentException(nameof(stream) + " cannot be write", nameof(stream));
             }
 
-            var length = 0;
             var current = 0L;
             var buffer = new byte[8 * 1024];
             var sourceStream = await this.HttpResponse.Content.ReadAsStreamAsync().ConfigureAwait(false);
 
-            var args = new ProgressEventArgs(current, this.FileSize, false);
-            this.DownloadProgressChanged?.Invoke(this, args);
-
-            while ((length = await sourceStream.ReadAsync(buffer, 0, buffer.Length).ConfigureAwait(false)) > 0)
+            while (true)
             {
+                var length = await sourceStream.ReadAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
+                var isCompleted = length == 0;
+
                 current = current + length;
+                var total = this.FileSize;
+                if (isCompleted == true && total == null)
+                {
+                    total = current;
+                }
 
-                args = new ProgressEventArgs(current, this.FileSize, false);
+                var args = new ProgressEventArgs(current, total, isCompleted);
                 this.DownloadProgressChanged?.Invoke(this, args);
 
+                if (isCompleted == true)
+                {
+                    break;
+                }
                 await stream.WriteAsync(buffer, 0, length).ConfigureAwait(false);
             }
-
-            args = new ProgressEventArgs(current, this.FileSize, true);
-            this.DownloadProgressChanged?.Invoke(this, args);
         }
     }
 }

WebApiClient/Parameterables/MulitpartFile.cs

@@ -116,19 +116,18 @@ async Task IApiParameterable.BeforeRequestAsync(ApiActionContext context, ApiPar
         private UploadStream GetUploadStream()
         {
             var inner = this.stream ?? new FileStream(this.filePath, FileMode.Open, FileAccess.Read);
-            return new UploadStream(inner, this.RaiseUploadProgressChanged);
+            return new UploadStream(inner, this.OnUploadProgressChanged);
         }
 
         /// <summary>
         /// 触发上传进度变化事件
         /// </summary>
         /// <param name="e"></param>
-        private void RaiseUploadProgressChanged(ProgressEventArgs e)
+        protected virtual void OnUploadProgressChanged(ProgressEventArgs e)
         {
             this.UploadProgressChanged?.Invoke(this, e);
         }
 
-
         /// <summary>
         /// 表示上传数据流
         /// </summary>
@@ -147,7 +146,7 @@ private class UploadStream : Stream
             /// <summary>
             /// 进度事件处理者
             /// </summary>
-            private readonly Action<ProgressEventArgs> eventArgsHandler;
+            private readonly Action<ProgressEventArgs> progressChangedHandler;
 
             /// <summary>
             /// 记录当前字节数
@@ -158,12 +157,12 @@ private class UploadStream : Stream
             /// 上传数据流
             /// </summary>
             /// <param name="inner">内部流</param>
-            /// <param name="eventArgsHandler">进度事件处理者</param>
+            /// <param name="progressChangedHandler">进度事件处理者</param>
             /// <exception cref="ArgumentNullException"></exception>
-            public UploadStream(Stream inner, Action<ProgressEventArgs> eventArgsHandler)
+            public UploadStream(Stream inner, Action<ProgressEventArgs> progressChangedHandler)
             {
                 this.inner = inner ?? throw new ArgumentNullException(nameof(inner));
-                this.eventArgsHandler = eventArgsHandler ?? throw new ArgumentNullException(nameof(eventArgsHandler));
+                this.progressChangedHandler = progressChangedHandler ?? throw new ArgumentNullException(nameof(progressChangedHandler));
 
                 try
                 {
@@ -193,7 +192,7 @@ public UploadStream(Stream inner, Action<ProgressEventArgs> eventArgsHandler)
             public override long Length => this.inner.Length;
 
             /// <summary>
-            /// 获取数据指针公交车
+            /// 获取数据指针位置
             /// </summary>
             public override long Position
             {
@@ -223,7 +222,7 @@ public override int Read(byte[] buffer, int offset, int count)
 
                 this.currentBytes = this.currentBytes + length;
                 var args = new ProgressEventArgs(this.currentBytes, this.totalBytes, isCompleted);
-                this.eventArgsHandler.Invoke(args);
+                this.progressChangedHandler.Invoke(args);
 
                 return length;
             }