C# VSTO使用格式查找单词

我最近对VSTO感兴趣，现在正试图构建一个word插件

基本上，我试图搜索所有斜体文本。但是我找不到任何帮助来做这件事

            Word.Range rng = Globals.ThisAddIn.Application.ActiveDocument.Paragraphs[1].Range;
            Word.Find searchRange = rng.Find;
            searchRange.ClearFormatting();
            searchRange.Format = true;

            searchRange.Font.Name = "Calibri";
            searchRange.Format = Font.Italic;

            object textToFind = "the";
            if (searchRange.Execute(ref textToFind, ref missing, ref missing, ref
            missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref
            missing, ref missing, ref missing, ref missing, ref missing, ref missing))
            {
                MessageBox.Show("Found text: " + textToFind, "Finding...");
                rng.Font.Italic = 1;
                rng.Font.Color = Word.WdColor.wdColorBlue;
            }

但是有很多错误，因为它不起作用

我的问题是如何定义搜索的格式