Highlight the entire line in a RichTextBox [duplicate]

问题

This question already has an answer here:

C# RichTextBox Highlight Line (1 answer)

Closed 3 years ago.

I want to highlight the entire line, from start to end doesn't matter whether characters are present or not and line may be blank but it should highlight the complete line.

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回答1:

This will highlight a full line in a RichTextBox if WordWrap is off:

void highLightALine(RichTextBox rtb, int line, Color hiLight)
{
    int i1 = rtb.GetFirstCharIndexFromLine(line);
    int i2 = rtb.GetFirstCharIndexFromLine(line + 1);
    if (i2 < 0) i2 = rtb.Text.Length;

    rtb.SelectionStart = i1;
    rtb.SelectionLength = i2 - i1;
    rtb.SelectionBackColor = hiLight;
}

Note that if WordWrap is true it will still highlight the line but only as far as it is visible. Its continuation on the next line will not be changed.

Also note that only Text can be highlighted. Empty space can't be highlighted afaik. Here is an example of trying to owner-draw an RTB subclass..

来源：https://stackoverflow.com/questions/37205546/highlight-the-entire-line-in-a-richtextbox