使用UploadFileAsync
.
订阅 wcUploader.UploadFileCompleted
和
wcUploader.UploadProgressChanged
事件,以便您可以获取上传进度和上传完成。
在下面的代码中,您可以检查我们如何订阅 UploadProgressChanged 并且我们可以获得e.ProgressPercentage
价值。
检查以下代码段:
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();
}
}
}
}
从这里提取的代码片段:
UploadFileAsync 不是异步的?