WebBrowser控件不＆QUOT;呈现＆QUOT; HTML [英] webbrowser control does not "render" html
问题描述
我使用WebBrowser控件正确显示HTML有问题。我的目标是自定义HTML添加到WebBrowser控件，让它显示出来，并保存，作为PNG截图。目前我使用Document.OpenNew和文件撰写（的htmlText）和Application.DoEvents（）。但是因为我在后台线程运行此，有时死锁。我知道罪魁祸首是Application.DoEvents（），这是给我的烦恼。
不过，如果我删除，并直接设置HTML来DocumentText财产，我怎么知道什么时候是完全渲染或加载。我用了DocumentCompleted事件，但似乎并没有工作，因为即使在事件触发后保存图像仍然是空的。
我也有螺纹为STA。
下面是现有code：
发个=新主题（新的ThreadStart（的createImage））;
th.SetApartmentState（ApartmentState.STA）;
th.Start（）;
th.Join（超时）;私人无效的createImage（）{
变种浏览器=新的web浏览器（）;
VAR DOC = browser.Document;
doc.OpenNew（假）;
doc.Write（＆LT; HTML和GT;＆LT;身体GT; ....＆LT; /身体GT;＆LT; HTML和GT;））;
//循环几秒钟
的for（int i = 0; I＆LT; 20;我++）
{
Application.DoEvents（）;
Thread.sleep代码（100）;
}
//保存到文件为PNG。
}
下面是code我想：
私人无效的createImage（）{
变种浏览器=新的web浏览器（）;
布尔docComplete = FALSE;
browser.DocumentCompleted + =新WebBrowserDocumentCompletedEventHandler（
（对象发件人，WebBrowserDocumentCompletedEventArgs参数）=＆GT;
{docComplete = TRUE; }
）;
browser.DocumentText =＆LT; HTML和GT; .....;
而（！_docComplete）
{
Thread.sleep代码（100）;
}
// 保存图片
// :-(不工作
}
您必须创建一个线程中STA，这仅仅是在后台线程运行web浏览器的方式。
bw.SetApartmentState（ApartmentState.STA）;
有没有关于的HTMLDocument等待信息.WRITE方法。如果没有需要，那么你可以添加DocumentCompleted处理不是的DoEvents
私人无效captureImageThread（字符串HTML）{
VAR线程=新主题（（）=＆GT; {
变种浏览器=新的web浏览器（）;
browser.DocumentCompleted + = browser_DocumentCompleted;
browser.DocumentText = HTML;
Application.Run（）;
}）;
thread.SetApartmentState（ApartmentState.STA）;
thread.Start（）;
}无效browser_DocumentCompleted（对象发件人，WebBrowserDocumentCompletedEventArgs E）{
VAR BR =发件人作为web浏览器;
//保存形象在这里
Application.ExitThread（）; //停止线程
}
I am having problem using webbrowser control to correctly display html. My goal is to add custom html to a webbrowser control, have it displayed, and save the screenshot of that as png. Currently I am using Document.OpenNew and Document.Write(htmlText) and Application.DoEvents(). However since I am running this in a background thread, sometimes it deadlocks. I know the culprit is Application.DoEvents() which is giving me troubles.
However, if I remove that and set the html directly to DocumentText property, how do I know when it is fully "rendered" or loaded. I used the DocumentCompleted Event but that does not seem to work since the image that is saved is still empty even after the event fires.
I also have the thread as STA.
Here is the existing code:
Thread th = new Thread(new ThreadStart(createImage));
th.SetApartmentState(ApartmentState.STA);
th.Start();
th.Join(TIMEOUT);
private void createImage() {
var browser = new WebBrowser();
var doc = browser.Document;
doc.OpenNew(false);
doc.Write("<html><body>....</body><html>)");
//loop for few seconds
for(int i=0; i<20; i++)
{
Application.DoEvents();
Thread.Sleep(100);
}
//save to file as png.
}
Here is the code I am trying:
private void createImage() {
var browser = new WebBrowser();
bool docComplete = false;
browser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(
(Object sender, WebBrowserDocumentCompletedEventArgs args) =>
{ docComplete = true; }
);
browser.DocumentText = "<html>.....";
while (!_docComplete)
{
Thread.Sleep(100);
}
// save image
// :-( not working
}
You have to create thread as STA, that is only the way to run WebBrowser in a background thread.
bw.SetApartmentState(ApartmentState.STA);
There is no information about waiting in HtmlDocument.Write Method. If is yet required then you can add DocumentCompleted handler instead of DoEvents
private void captureImageThread(string html) {
var thread = new Thread(() => {
var browser = new WebBrowser();
browser.DocumentCompleted += browser_DocumentCompleted;
browser.DocumentText = html;
Application.Run();
});
thread.SetApartmentState(ApartmentState.STA);
thread.Start();
}
void browser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) {
var br = sender as WebBrowser;
// save image here
Application.ExitThread(); // Stops the thread
}
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