我有一个for循环：
for (i = 0; i <= 21; i++)
{
webB.Navigate(URL);
}
webB是一个webBrowser控件,我是一个int.
我想等待浏览器完成导航.
然而,我找到了this：
>我不想使用任何API或插件
>我不能使用另一个void函数,如this answer所示
有没有办法在for循环中等待？
解决方法
假设您在WinFroms应用程序中托管WebBrowser,您可以使用async / await模式轻松高效地循环执行.试试这个：
async Task DoNavigationAsync()
{
TaskCompletionSource<bool> tcsNavigation = null;
TaskCompletionSource<bool> tcsDocument = null;
this.WB.Navigated += (s,e) =>
{
if (tcsNavigation.Task.IsCompleted)
return;
tcsNavigation.SetResult(true);
};
this.WB.DocumentCompleted += (s,e) =>
{
if (this.WB.ReadyState != WebBrowserReadyState.Complete)
return;
if (tcsDocument.Task.IsCompleted)
return;
tcsDocument.SetResult(true);
};
for (var i = 0; i <= 21; i++)
{
tcsNavigation = new TaskCompletionSource<bool>();
tcsDocument = new TaskCompletionSource<bool>();
this.WB.Navigate("http://www.example.com?i=" + i.ToString());
await tcsNavigation.Task;
Debug.Print("Navigated: {0}",this.WB.Document.Url);
// navigation completed,but the document may still be loading
await tcsDocument.Task;
Debug.Print("Loaded: {0}",this.WB.DocumentText);
// the document has been fully loaded,you can access DOM here
}
}
现在,了解DoNavigationAsync以异步方式执行非常重要.这是你如何从Form_Load调用它并处理它的完成：
void Form_Load(object sender,EventArgs e)
{
var task = DoNavigationAsync();
task.ContinueWith((t) =>
{
MessageBox.Show("Navigation done!");
},TaskScheduler.FromCurrentSynchronizationContext());
}
我已经回答了类似的问题here.
