EventHandler在Silverlight中使用MVVM不触发;RIA

本文关键字：RIA MVVM Silverlight EventHandler | 更新日期: 2023-09-27 18:11:34

所以我一定是做错了什么，只是不确定它是什么。我原来的PoC工作良好，但不是MVVM，所以我在翻译中丢失了一些东西。

所以我浏览到一个文件选择上传，一切都开始正常工作。它将第一个块传输到服务器，然后我的完整事件永远不会被调用。这将发送数组中所有额外的块，所以文件是不完整的。

我是不是漏了一步?

如果重要的话，服务是在IIS7上设置的，但我不确定是否需要在服务端设置任何东西来实现这一点。当我使用XAML代码时，它只是在PoC代码中"工作"。

模型代码: 

public void uploadChunks(int index, string fileName)
    {
        FileUpload fileUpload = new FileUpload();
        FileUpload.FileName = fileName;
        FileUpload.chunk = fileChunks[index];
        context.UploadFileAsync(fileUpload);
    }
FileUploadServiceSoapClient context = new FileUploadServiceSoapClient("BasicHttpBinding_FileUploadServiceSoap");
    int chunkSize = 15306;
    public List<byte[]> fileChunks;
    public double TotalChunks { get; set; }
    /// <summary>
    /// Convert file to an array of file chunks to stream to the upload location
    /// </summary>
    /// <param name="imageFile"></param>
    public void convertToChunks(byte[] imageFile)
    {
        TotalChunks = Math.Ceiling((double)imageFile.Length / (double)chunkSize);
        fileChunks = new List<byte[]>();
        for (int i = 0; i < TotalChunks; i++)
        {
            byte[] chunk;
            int startIndex = i * chunkSize;
            if (startIndex + chunkSize > imageFile.Length)
                chunk = new byte[imageFile.Length - startIndex];
            else
                chunk = new byte[chunkSize];
            Array.Copy(imageFile, startIndex, chunk, 0, chunk.Length);
            fileChunks.Add(chunk);
        }
    }
<<p> ViewModel代码/strong> 
public UploadViewModel()
    {
        uploadModel = new UploadModel(); // important – must initialize model
        OpenFileCommand = new RelayCommand(OpenDialog);
        StatusText = "Please select a file to upload";
        context.UploadFileCompleted += new EventHandler<AsyncCompletedEventArgs>(context_UploadFileCompleted);
    }
 private void OpenDialog()
    {
        OpenFileDialog ofd = new OpenFileDialog();
        if ((bool)ofd.ShowDialog())
        {
            _fileName = ofd.File.Name;
            FileStream fs = ofd.File.OpenRead();
            fileSize = (double)fs.Length;
            index = 0;
            sendData = 0;
            byte[] file = new byte[fs.Length];
            fs.Read(file, 0, file.Length);
            // call our model and convert file into chunks
            uploadModel.convertToChunks(file);
            // start upload process, this only sends the first chunk all subsquent chunks
            // are sent on the context_UploadFileToCrmCompleted function
            uploadModel.uploadChunks(index, _fileName);
        }
    }
void context_UploadFileCompleted(object sender, AsyncCompletedEventArgs e)
    {
        if (e.Error == null)
        {
            sendData += uploadModel.fileChunks[index].Length;
            TotalFileSize = byteTranslation(sendData) + "/" + byteTranslation(fileSize);
            if ((index + 1) < uploadModel.fileChunks.Count)
            {
                this.CurrentProgress = index / uploadModel.fileChunks.Count;
                index += 1;
                uploadModel.uploadChunks(index, _fileName);
            }
            else
            {
                StatusText = "Successfully uploaded. Submitting to the file repository...";
                // Submit the upload to SharePoint
            }
        }
    }

EventHandler在Silverlight中使用MVVM不触发;RIA

我希望我没有错过任何东西…你有两个FileUploadServiceSoapClients吗?

一个在ViewModel中，一个在模型中。您正在调用模型中的服务，但已完成的处理程序被分配给ViewModel的上下文。

所以你必须写

uploadModel.context.UploadFileCompleted += new EventHandler<AsyncCompletedEventArgs>(context_UploadFileCompleted);
不是

context.UploadFileCompleted += new EventHandler<AsyncCompletedEventArgs>(context_UploadFileCompleted);

也许你最好不要在viewModel中直接使用ServiceClient，而是传递一个回调或让模型引发一个自己的事件。

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