如何使用 mshtml 在 textarea 中输入文本

Question

I am facing a problem I have to fill a TextArea programatically. I used the following code.

 System.Windows.Forms.HtmlElement reviewText = myDoc.GetElementById("review-text");
 reviewText.InnerText = Program.mainForm.richTextBox1.Text.Trim();

This works fine and it sets the text in TextArea control. The problem that I am facing is that this text appears light gary. When the user clicks over this text it disappears. It happens only on first click.

So I tried the following code to first click this box and then set the text.

 reviewText.InvokeMember("click");

And then tried to set the text in the TextArea but got the same behaviour.

I dug into the source of the page and found some script associated with this TextArea.

Source of TextArea

<textarea onkeyup="javascript:yelp.ui.widget.countChars(this.form.comment,5000);"   onkeydown="javascript:yelp.ui.widget.countChars(this.form.comment,5000);" name="comment" id="review-text" class="form400" rows="8" cols="40" style="height: 86px;"></textarea>

Script associated with TextArea

 <script type="text/javascript">
   var bizName = "Geary Club";
   if ($('review-text')) 
   {
     new yelp.ui.widget.DefaultValueTextField($('review-text'), 'Please write here');
   } 

Will somebody suggest to me how to insert the text into this TextArea control?

Answer 1

Is this an ASP.NET web app? If it is, the System.Windows.Forms.HtmlElement is a problem. What I think is going on is that you need to somehow disable the new yelp.ui.widget.DefaultValueTextField JavaScript code when you're pre-filling the TextArea. Are you able to use an ASP.NET TextBox control with the multi-line properties set? If so, I'd use that and change your top code to just set the.Text property of the Textbox control.

Either way, in the Javascript (if this is jQuery), I'd do this:

if ($('review-text') && $('review-text').val() != "")
{
  new yelp.ui.widget.DefaultValueTextField($('review-text'), 'Please write here');
}

That way the default value is only set if there is no text.

Answer 2

I changed the HTML of text area.And remove the class="form400 default_valued_text_field" attribute from its html.

myDoc = this.webBrowser1.Document;

myDoc.GetElementById("review-text").OuterHtml = "<textarea id=\"review-text\"   onkeyup=\"javascript:ui.widget.countChars(this.form.comment,5000);\" onkeydown=\"javascript:ui.widget.countChars(this.form.comment,5000);\" name=\"comment\" rows=\"8\" cols=\"40\" style=\"height: 86px;\"></textarea>";

After that i set the inner text of this element

myDoc.GetElementById("review-text").InnerText = "Testing";