public OutputWindow() { InitializeComponent(); Dock = DockStyle.Fill; //OutputTextBox.Dock = DockStyle.None; //OutputTextBox.Width = 300; //OutputTextBox.Height = 4000; OutputTextBox.ScrollBars = RichTextBoxScrollBars.Horizontal; Controls.Add(OutputTextBox); Controls.Add(vScrollBar); //Controls.Add(hScrollBar); using (var g = OutputTextBox.CreateGraphics()) { _lineHeight = TextRenderer.MeasureText(g, "I", OutputTextBox.Font).Height; } OutputTextBox.MouseWheel += (s, a) => OnMouseWheel(a); vScrollBar.Scroll += (sender, args) => RefreshOutput(); OutputTextBox.MouseDoubleClick += (sender, args) => { ClickedLine(args.Location.Y / _lineHeight); }; ResumeLayout(); }