非常简单的 Silverlight 文件上传示例 [英] Very simple Silverlight File Upload example

问题描述

我正在 Silverlight 中寻找一个非常示例的文件上传代码片段/解决方案.完成搜索后，我发现了许多控件/项目，但它们都非常复杂；支持多文件上传、文件上传进度、图片重采样等多种类.

I'm looking for a very example file upload code snipplet/solution in Silverlight. Having done search I've found numerous controls/projects but all of them were quite complex; supporting multiple file upload, file upload progress, image re-sampling and lots of classes.

我正在寻找具有简短、干净且易于理解的代码的最简单的场景.

I'm looking for the simplest possible scenario with short, clean and easy to understand code.

推荐答案

这段代码很短而且(希望)容易理解:

This code is pretty short and (hopefully) easy to understand:

public const int CHUNK_SIZE = 4096; 
public const string UPLOAD_URI = "http://localhost:55087/FileUpload.ashx?filename={0}&append={1}"; 
private Stream _data; 
private string _fileName; 
private long
_bytesTotal; 
private long _bytesUploaded;   
private void UploadFileChunk() 
{
    string uploadUri = ""; // Format the upload URI according to wether the it's the first chunk of the file
    if (_bytesUploaded == 0)
    {
        uploadUri = String.Format(UPLOAD_URI,_fileName,0); // Dont't append
    }
    else if (_bytesUploaded < _bytesTotal)
    {
        uploadUri = String.Format(UPLOAD_URI, _fileName, 1); // append
    }
    else
    {
        return;  // Upload finished
    }

    byte[] fileContent = new byte[CHUNK_SIZE];
    _data.Read(fileContent, 0, CHUNK_SIZE);

    WebClient wc = new WebClient();
    wc.OpenWriteCompleted += new OpenWriteCompletedEventHandler(wc_OpenWriteCompleted);
    Uri u = new Uri(uploadUri);
    wc.OpenWriteAsync(u, null, fileContent);
    _bytesUploaded += fileContent.Length; 
}   

void wc_OpenWriteCompleted(object sender, OpenWriteCompletedEventArgs e) 
{
    if (e.Error == null)
    {   
        object[] objArr = e.UserState as object[];
        byte[] fileContent = objArr[0] as byte[];
        int bytesRead = Convert.ToInt32(objArr[1]);
        Stream outputStream = e.Result;
        outputStream.Write(fileContent, 0, bytesRead);
        outputStream.Close();
        if (_bytesUploaded < _bytesTotal)
        {
            UploadFileChunk();
        }
        else
        {
            // Upload complete
        }
    } 
}

有关完整的可下载解决方案，请参阅我的博客文章:Silverlight 中的文件上传 - 一个简单的解决方案

For a complete downloadable solution see my blog post on this: File Upload in Silverlight - a Simple Solution

这篇关于非常简单的 Silverlight 文件上传示例的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！