winform 上传

public class ImitateSelectFile
{
public void Select(HtmlElement htmlEle, string fileFullPath)
{
htmlEle.Focus();

SendKeys.Send("{Tab}");

SendKeys.Send(" ");

DelayAndOperateDialog(fileFullPath);

}
Random rnd = new Random();
void DelayAndOperateDialog(string fileFullPath)
{
BackgroundWorker b = new BackgroundWorker();

b.RunWorkerCompleted += new RunWorkerCompletedEventHandler(b_RunWorkerCompleted);

b.DoWork += new DoWorkEventHandler(b_DoWork);

b.RunWorkerAsync(fileFullPath);

}

void b_DoWork(object sender, DoWorkEventArgs e)
{
Thread.Sleep(3000);

e.Result = e.Argument;
}

void b_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{

SendKeys.Send(e.Result as string);

SendKeys.Send("{Enter}");
}
}

 public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            
        }

        void init()
        {
            var aa =webBrowser1.Document;
            HtmlElement elefile = aa.GetElementById("f_test");
            ImitateSelectFile temobj = new ImitateSelectFile();
            temobj.Select(elefile, "D:\NottulnHerbst_ROW11202790843_1920x1080.jpg");

        }

        private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            //init();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            init();
            var aa = webBrowser1.Document;
            var bb= aa.GetElementById("f_test");
            var cc = bb;
        }
    }