我一直在尝试从iOS上Xamarin表单的JS代码调用操作。一旦我点击代码js就不会被调用。这是我一直在测试的一个例子。一旦我点击了文本，但功能没有被触发，我不想在点击按钮后显示动作，而是在我点击文本后显示。请告诉我我做错了什么。
<StackLayout x:Name="slHybridView" >
</StackLayout>
public MainPage()
{
InitializeComponent();
BindingContext = new LearningPageViewModel();
((LearningPageViewModel)BindingContext).TextChanged += TextChanged;
hybridWebView = new HybridWebView()
{
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.FillAndExpand,
Content = ((LearningPageViewModel)BindingContext).ArticleHtmlFormat,
};
hybridWebView.RegisterAction(data => DisplayAlert("Alert", "Hello " + data, "OK"));
slHybridView.Children.Clear();
slHybridView.Children.Add(hybridWebView);
}
public class HybridWebViewRenderer : WkWebViewRenderer, IWKScriptMessageHandler
{
const string JavaScriptFunction = "function invokeCSharpAction(data){window.webkit.messageHandlers.invokeAction.postMessage(data);}";
WKUserContentController userController;
public HybridWebViewRenderer()
{
}
public HybridWebViewRenderer(WKWebViewConfiguration config) : base(config)
{
userController = config.UserContentController;
var script = new WKUserScript(new NSString(JavaScriptFunction), WKUserScriptInjectionTime.AtDocumentEnd, false);
userController.AddUserScript(script);
userController.AddScriptMessageHandler(this, "invokeAction");
}
protected override void OnElementChanged(VisualElementChangedEventArgs e)
{
base.OnElementChanged(e);
if (e.OldElement != null)
{
userController.RemoveAllUserScripts();
userController.RemoveScriptMessageHandler("invokeAction");
HybridWebView hybridWebView = e.OldElement as HybridWebView;
hybridWebView.Cleanup();
}
if (e.NewElement != null)
{
var html = string.Empty;
var iOSHtmlWithScaling = html.Insert(0, "<meta name='viewport' content='width=device-width,initial-scale=1,maximum-scale=1' />");
var script = new WKUserScript(new NSString(JavaScriptFunction), WKUserScriptInjectionTime.AtDocumentEnd, false);
Configuration.UserContentController.AddUserScript(script);
Configuration.UserContentController.AddScriptMessageHandler(this, JavaScriptFunction);
LoadData(((HybridWebView)Element).Content, iOSHtmlWithScaling, "utf-8", new NSUrl(""));
}
}
public void DidReceiveScriptMessage(WKUserContentController userContentController, WKScriptMessage message)
{
((HybridWebView)Element).InvokeAction(message.Body.ToString());
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
((HybridWebView)Element).Cleanup();
}
base.Dispose(disposing);
}
}
public LearningPageViewModel()
{
articleHtmlFormat = ArticleHtml();
}
public string ArticleHtml()
{
var articleHtml = @"<html>
<head>
<meta name='viewport' content='width=device-width,initial-scale=1,maximum-scale=1' />
</head>
<body class='avat'>
<style>
.avat {
font-family: sans-serif;
font-size: 15px;
text-align: justify;
}
.title {
font-size: 16px;
}
.red {
color: red;
}
.word {
font-weight: bold;
}
.phrase {
text-decoration: underline;
}
</style>
<script type='text/javascript'>
function invokeCSCode(data) {
var els = document.getElementsByClassName('red');
while (els[0]) {
els[0].classList.remove('red');
}
invokeCSharpAction(data);
var my_element = document.querySelector('[sentenceId=' + data + ']');
my_element.scrollIntoView({
behavior: 'smooth',
block: 'center',
inline: 'nearest'
});
var sentenceName = my_element.getAttribute('sentenceName');
if (data[0] === 's')
{
var x = document.querySelectorAll('[sentenceName=' + sentenceName + ']');
var i;
for (i = 0; i < x.length; i++)
{
x[i].classList.add('red');
}
}
else
{
my_element.classList.add('red');
}
}
function scrollToPosition(data) {
var els = document.getElementsByClassName('red');
while (els[0]) {
els[0].classList.remove('red');
}
var my_element = document.querySelector('[sentenceId=' + data + ']');
my_element.scrollIntoView({
behavior: 'smooth',
block: 'center',
inline: 'nearest'
});
var sentenceName = my_element.getAttribute('sentenceName');
if (data[0] === 's')
{
var x = document.querySelectorAll('[sentenceName=' + sentenceName + ']');
var i;
for (i = 0; i < x.length; i++)
{
x[i].classList.add('red');
}
}
else
{
my_element.classList.add('red');
}
}
</script>
";
var spans = FindAllClickableSpans(Article()).ToArray();
for (int i = 0; i < spans.Length; i++)
{
articleHtml += "<span ";
articleHtml += " sentenceId='" + i + "' onclick='javascript: invokeCSCode(\"" + i + "\");' sentenceName='" + i + "'>" + spans[i] + "</span>";
}
articleHtmlFormat = articleHtml;
return articleHtmlFormat;
}
public string Article()
{
return @"Excuse me,” said a girl, “you look lost. Can I help you?”\“Yes, please. Thank you.";
}
private IEnumerable<string> FindAllClickableSpans(string article)
{
article = article.ToLower();
return article.Split('.');
}