由于ASP.NET验证程序的复杂性以某种方式弄乱了正常的form.submit()流，因此必须调用提交按钮的click方法:>

Because of the complication of the ASP.NET validators somehow messing with the normal form.submit() flow the submit button's click method had to be called:

WebBrowser1.Document.getElementById("mybutton").InvokeMember("click");