Tracking upload progress of WebClient

问题

So I am currently uploading files via a php script on my webserver using the following code:

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);

What I want to know is how would I use this, or a different method to track how much it has uploaded and display it on a progress bar?

Thanks.

回答1:

Use UploadFileAsync.

Suscribe to wcUploader.UploadFileCompleted and wcUploader.UploadProgressChangedevents so you can get the upload progress and the upload completion.

In the following code you can check how we suscribe to UploadProgressChanged and we can get e.ProgressPercentage value.

Check the following snippet:

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();
            }
        }
    }
}

Code snippet extracted from here:

UploadFileAsync not asynchronous?

来源：https://stackoverflow.com/questions/16728622/tracking-upload-progress-of-webclient

标签

upload

progress-bar

webclient