different format into one single line Interop.word

Question

I've been trying to figure out how to insert 2 different formats into the same paragraph using interop.word in c# like this:

hello planet earth here's what I want to do

Answer 1

Assuming you have your document defined as oDoc, the following code should get you the desired result:

Word.Paragraph oPara = oDoc.Content.Paragraphs.Add(ref oMissing);
oPara.Range.Text = "hello planet earth here's what I want to do";
object oStart = oPara.Range.Start + 13;
object oEnd = oPara.Range.Start + 18;

Word.Range rBold = oDoc.Range(ref oStart, ref oEnd);
rBold.Bold = 1;

Answer 2

I had to modify Dennis' answer a little to get it to work for me.

What I'm doing it totally automated, so I have to only work with variables.

private void InsertMultiFormatParagraph(string text, int size, int spaceAfter = 10) {
    var para = docWord.Content.Paragraphs.Add(ref objMissing);

    para.Range.Text        = text;
    // Explicitly set this to "not bold"
    para.Range.Font.Bold   = 0;
    para.Range.Font.Size   = size;
    para.Format.SpaceAfter = spaceAfter;

    var start = para.Range.Start;
    var end   = para.Range.Start + text.IndexOf(":");

    var rngBold = docWord.Range(ref objStart, ref objEnd);
    rngBold.Bold = 1;

    para.Range.InsertParagraphAfter();
}

The main difference that made me want to make this post was that the Paragraph should be inserted AFTER the font is changed. My initial thought was to insert it after setting the SpaceAfter property, but then the objStart and objEnd values were tossing "OutOfRange" Exceptions. It was a little counter-intuitive, so I wanted to make sure everyone knew.

Answer 3

The following code seemed to work the best for me when formatting a particular selection within a paragraph. Using Word's built in "find" function to make a selection, then formatting only the selected text. This approach would only work well if the text to select is a unique string within the selection. But for most situations I have run across, this seems to work.

        oWord.Selection.Find.Text = Variable_Containing_Text_to_Select; // sets the variable for find and select
        oWord.Selection.Find.Execute(); // Executes find and select
        oWord.Selection.Font.Bold = 1; // Modifies selection
        oWord.Selection.Collapse();  // Clears selection

Hope this helps someone!