cksubs cksubs - 22 days ago 5
C# Question

Tooltip that's not linked to any particular control

I'm trying to make something like a spellchecker, that will list possible words under the current caret position. I thought I would do this by creating a tooltip, moving it according to the caret's location, and changing the text inside the tooltip.

I'm having problems.

I'm trying to show the tooltip with

tip.Show(form, x, y);


However, this app is running from the systray. It has no GUI elements aside from that? What do I use as the
form
parameter? the
notifyIcon1
,
Form1
, etc. do not work.

I would start with an example that displayed a static tooltip that moved along with my mouse cursor or something. Can someone point me in the right direction?

Thanks

Answer

I posted an answer in this thread that uses a transparent, maximized for to simulate drawing a tooltip anywhere on the screen, including the desktop. Maybe it will help: Creating a tooltip from a system-tray only app

Edit: Copied the code over from the linked post for ease of reading :-)

Here you go, use a transparent, maximized form that you BringToFront() before showing the ToolTip

Form1 Code:

using System;
using System.Windows.Forms;

namespace SO_ToolTip
{
    public partial class Form1 : Form
    {
        Random _Random = new Random();
        ToolTip _ToolTip = new ToolTip();

        public Form1()
        {
            InitializeComponent();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            BringToFront();
            _ToolTip.Show("Blah blah... Blah blah... Blah blah...", this, _Random.Next(0, Width), _Random.Next(0, Height), 10000);
        }
    }
}

Form1 Designer Code: So you can see the forms properties:

namespace SO_ToolTip
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.components = new System.ComponentModel.Container();
            this.timer1 = new System.Windows.Forms.Timer(this.components);
            this.SuspendLayout();
            // 
            // timer1
            // 
            this.timer1.Enabled = true;
            this.timer1.Interval = 1000;
            this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(284, 264);
            this.ControlBox = false;
            this.MaximizeBox = false;
            this.MinimizeBox = false;
            this.Name = "Form1";
            this.Opacity = 0;
            this.ShowIcon = false;
            this.ShowInTaskbar = false;
            this.WindowState = System.Windows.Forms.FormWindowState.Maximized;
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.Timer timer1;

    }
}

Update: With ControlBox = false; and Opacity = 0; the form is not only visually transparent but is immune to user input. That is even when the Form1 above if the top most window clicking in it's area falls through to the next window/desktop. Just as if the form wasn't there. The BringToFront() before showing the tooltip is required because otherwise the tooltip could be drawn under other windows, which is not what you want.