如何防止MS-Word内存错误

Question

Is there a way of releasing memory and preventing the following code from crashing in MS-Word? I get the following error message:

This method or property is not available because there is a memory or disk problem.

Sub vbaTest()
Dim doc As Document
Dim sty As Style
Dim s As Style
Dim readingOrder As WdReadingOrder
Dim i As Integer
    Set doc = ActiveDocument
    Set sty = doc.Styles(wdStyleNormal)
    For i = 0 To 100
        readingOrder = sty.ParagraphFormat.readingOrder
        For Each s In doc.Styles
            s.Font.SizeBi = s.Font.Size + 3
        Next
        Set s = Nothing
    Next
    Set sty = Nothing
End Sub

-- or --

public void CsharpRibbon_Click(O.IRibbonControl c)
{
    var doc = app.ActiveDocument;
    var style = doc.Styles[Wd.WdBuiltinStyle.wdStyleNormal];
    for (int i = 0; i < 100; i++)
    {
        var readingOrder = style.ParagraphFormat.ReadingOrder;
        foreach (Wd.Style s in doc.Styles)
            s.Font.SizeBi = s.Font.Size + 3;
    }
}

The code above doesn't really do anything helpful. I have a ribbon button that I noticed causes a crash on repeated button presses (around 5 or 6 times in a Word session). I stripped back the code and added the for loop to simulate multiple presses of the button.

Answer 1

I'm not sure if this is your error, because 100 iterations doesn't seem like enough to cause memory errors, but VSTO uses COM objects, which must be released after use. The simple way to do this is:

Paragraph para = Paragraphs[1];
// etc.
Marshal.ReleaseComObject(yourObject);

There's also VSTO Contrib which makes this a little easier. Instead of making a call to ReleaseComObject , you would do something like this:

using (var doc = Document.WithComCleanup())
using (var paragraphs = doc.Resource.Paragraphs.WithComCleanup())
{
    int count = paragraphs.Resource.Count;
    // etc.
}

Or, for collections:

foreach (Paragraph para in Paragraphs.ComLinq<Paragraph>())
{
    int pageBreakBefore = para.PageBreakBefore;
    // etc.
}