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We currently have an application (Windows service) that connects to another of our applications and grabs invoices. In the invoices there is a RTF field for the footer/header fields. When we grab the data the RTF is converted to plain text with the following code:

public static string ConvertFromRTFToPlainText(string rtfString)
{
    if (rtfString == null)
        return null; 

    System.Windows.Forms.RichTextBox rtBox = new System.Windows.Forms.RichTextBox();

    if (rtfString.StartsWith("{\\rtf1"))
        rtBox.Rtf = rtfString;
    else
        rtBox.Text = rtfString;

    return rtBox.Text;
}

This has worked for the most part but in some cases (one particular client gets it everytime) I get this exception:

Exception Message:Error creating window handle.
Stack trace:
at System.Windows.Forms.NativeWindow.CreateHandle(CreateParams cp)
at System.Windows.Forms.Control.CreateHandle()
at System.Windows.Forms.TextBoxBase.CreateHandle()
at System.Windows.Forms.RichTextBox.set_Rtf(String value)
at SmartTrade.Common.API.Tools.RTFHelperUtility.ConvertFromRTFToPlainText(String rtfString)
at SmartTrade.Desktop.Proxy.API.ObjectMapper.InvoiceObjectMapper.CovertToAPIInvoice(Invoice domainInvoice)

Any help on why this is happening or how we can work around it would be much appreciated.

Edit: Thanks to Jeremy for the explanation, I am after suggestions for RTF conversion alternatives.

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2 回答 2

3

I would say this is probably thrown on terminal type machines that don't have the UI libraries installed? Or possibly don't have them loaded (ie - if no user is logged in)

It's generally not a great idea to use UI libraries in a service, because there is no guarantee that those libraries are accessible if no user is logged in.

I would find a different way to remove the RTF formatting

于 2012-05-01T20:25:58.433 回答
3

I ended up using this. I know that it may not parse 100% of RTF text but we ran it against our live data to test it and it works fine for our purposes. 

Regex.Replace(rtfString, @"\{\*?\\[^{}]+}|[{}]|\\\n?[A-Za-z]+\n?(?:-?\d+)?[ ]?", "");
于 2012-05-10T21:28:11.200 回答