跟踪 WebClient 的上传进度答案

【问题标题】：Tracking upload progress of WebClient跟踪 WebClient 的上传进度
【发布时间】：2013-05-19 16:19:40
【问题描述】：

所以我目前正在使用以下代码通过我的网络服务器上的 php 脚本上传文件：

string file = "dp.jpg";

System.Net.WebClient Client = new System.Net.WebClient();
Client.Headers.Add("Content-Type", "binary/octet-stream");
byte[] result = Client.UploadFile("http://localhost/upload.php", "POST", file);

String response = System.Text.Encoding.UTF8.GetString(result, 0, result.Length);

我想知道我将如何使用它，或者使用不同的方法来跟踪它已上传了多少并将其显示在进度条上？

谢谢。

【问题讨论】：

标签： c# upload progress-bar webclient

【解决方案1】：

使用UploadFileAsync。

订阅wcUploader.UploadFileCompleted 和 wcUploader.UploadProgressChangedevents 这样你就可以得到上传进度和上传完成。

在以下代码中，您可以检查我们如何订阅 UploadProgressChanged 和我们可以得到e.ProgressPercentage 的值。

检查以下sn-p：

using System;
using System.Net;
using System.Text;
using System.Threading;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        private readonly WebClient wcUploader = new WebClient();

        public Form1()
        {
            InitializeComponent();

            wcUploader.UploadFileCompleted += UploadFileCompletedCallback;
            wcUploader.UploadProgressChanged += UploadProgressCallback;
        }


        private void UploadFileCompletedCallback(object sender, UploadFileCompletedEventArgs e)
        {
            // a clever way to handle cross-thread calls and avoid the dreaded
            // "Cross-thread operation not valid: Control 'textBox1' accessed 
            // from a thread other than the thread it was created on." exception

            // this will always be called from another thread,
            // no need to check for InvokeRequired
            BeginInvoke(
                new MethodInvoker(() =>
                    {
                        textBox1.Text = Encoding.UTF8.GetString(e.Result);
                        button1.Enabled = true;
                    }));
        }

        private void UploadProgressCallback(object sender, UploadProgressChangedEventArgs e)
        {
            // a clever way to handle cross-thread calls and avoid the dreaded
            // "Cross-thread operation not valid: Control 'textBox1' accessed 
            // from a thread other than the thread it was created on." exception

            // this will always be called from another thread,
            // no need to check for InvokeRequired

            BeginInvoke(
                new MethodInvoker(() =>
                    {
                        textBox1.Text = (string)e.UserState + "\n\n"
                                        + "Uploaded " + e.BytesSent + "/" + e.TotalBytesToSend
                                        + "b (" + e.ProgressPercentage + "%)";
                    }));
        }

        private void button1_Click(object sender, EventArgs e)
        {
            textBox1.Text = "";

            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                button1.Enabled = false;
                string toUpload = openFileDialog1.FileName;
                textBox1.Text = "Initiating connection";
                new Thread(() =>
                           wcUploader.UploadFileAsync(new Uri("http://anyhub.net/api/upload"), "POST", toUpload)).Start();
            }
        }
    }
}

从这里提取的代码sn-p：

UploadFileAsync not asynchronous?

【讨论】：