在WPF TextBlock中突出显示文本

我试图在WPF TextBlock中突出显示或设置一些选定文本的背景。假设我有两个文本文件，我加载到内存中，完成diff，然后想要在WPF应用程序中显示。想象一下，循环遍历每一行，然后在文本块中添加文本，并根据删除、插入或相等的文本更改颜色。

for (int i = 0; i < theDiffs.Count; i++)
        {
            switch (theDiffs[i].operation)
            {
                case Operation.DELETE:
                    // set color to red on Source control version TextBlock
                    break;
                case Operation.INSERT:
                    WorkspaceVersion.AppendText(theDiffs[i].text);
                    // set the background color (or highlight) of appended text to green
                    break;
                case Operation.EQUAL:
                    WorkspaceVersion.AppendText(theDiffs[i].text);
                    // Set the background color (highlight) of appended text to yellow
                    break;
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }

case Operation.INSERT:
    // set the background color (or highlight) of appended text to green
    string text = theDiffs[i].text;
    Brush background = Brushes.Green;
    var run = new Run { Text = text, Background = background };
    WorkspaceVersion.Inlines.Add(run);
break;