GeckoFX 上的“AddMessageEventListener"错误 [英] Error in 'AddMessageEventListener' on GeckoFX
问题描述
我希望我的浏览器 (GeckoFX) 在单击网页中的按钮时执行 .NET 功能.我有以下代码:
I want that my browser (GeckoFX) executes a .NET function when clicking on a button in my webpage. I have the following code:
public Form1()
{
InitializeComponent();
AddMessageEventListener("myFunction", ((string s) => this.showMessage(s)));
browser.LoadHtml
(
@"<!DOCTYPE html>
<html><head>
<meta http-equiv=""Content-Type"" content=""text/html; charset=UTF-8"">
<script type=""text/javascript"">
function fireEvent(name, data)
{
event = document.createEvent('MessageEvent');
event.initMessageEvent(name, false, false, data, null, null, null, null);
document.dispatchEvent(event);
}
</script>
</head>
<body>fdsfsda
<input type=""button"" onclick=""fireEvent('myFunction', 'some data');"" value=""SHOW DATA"" />
</body></html>"
);
}
public void AddMessageEventListener(string eventName, Action<string> action)
{
browser.AddMessageEventListener(eventName, action);
}
private void showMessage(string s)
{
MessageBox.Show(s);
}
但是当运行该代码时，该行
But when running that code, the line
browser.AddMessageEventListener(eventName, action);
给我一个对象引用未设置为对象的实例"错误.我不明白，因为我已经检查过该行中的所有对象都已初始化.有人可以帮忙告诉我为什么会出现此错误吗?
gives me an 'Object reference not set to an instance of an object' error. I don't understand that because I have checked that all object in that line are initialized. Can somebody help and tell why I'm getting this error?
非常感谢！
推荐答案
尝试将 AddMessageEventListener 放在 LoadHtml 之后，如下所示:
Try to put AddMessageEventListener after LoadHtml like this:
browser.LoadHtml(@"<!DOCTYPE html>.....</html>");
AddMessageEventListener("myFunction", ((string s) => this.showMessage(s)));
并在您的 LoadHtml 中更改此行:
And change it this lines inside your LoadHtml:
event = document.createEvent('MessageEvent');
event.initMessageEvent(name, false, false, data, null, null, null, null);
这样:
var event = new MessageEvent(name,{'view': window, 'bubbles': false, 'cancelable': false, 'data': data});
您的新代码如下所示:
public Form1()
{
InitializeComponent();
browser.LoadHtml
(
@"<!DOCTYPE html>
<html><head>
<meta http-equiv=""Content-Type"" content=""text/html; charset=UTF-8"">
<script type=""text/javascript"">
function fireEvent(name, data)
{
var event = new MessageEvent(name,{'view': window, 'bubbles': false, 'cancelable': false, 'data': data});
document.dispatchEvent(event);
}
</script>
</head>
<body>fdsfsda
<input type=""button"" onclick=""fireEvent('myFunction', 'some data');"" value=""SHOW DATA"" />
</body></html>"
);
AddMessageEventListener("myFunction", ((string s) => this.showMessage(s)));
}
private void showMessage(string s)
{
MessageBox.Show(s);
}
这篇关于GeckoFX 上的“AddMessageEventListener"错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
