Custom tooltip using title, text, and image.
Custom tooltip using text only.
Custom tooltip using title only.
Custom tooltip using image only.
There are several ways to show additional information about a control, including ToolTip. When we used standard ToolTip, the tooltip is shown as a rectangular window with text inside, and often the tooltip covers the main object and it will interfere with our work, unless you call Show method of the tooltip and provide its relative position from the main object. The main issue is that the tooltip is always a rectangular box, except if the
IsBallon property of the tooltip is set to
true, but still we can't create a tooltip that has a custom shape. So, I need a tooltip that can display provided title, content, image, and avoid the area of main object by default, can be shown either relative location from the main object, or absolute location on the screen, and can be created using custom shape.
This tooltip will provides
ToolTipImage properties to each
ToolStripItem available. By default, this tooltip will be shown as a rounded corner rectangle, contains provided property (tooltip (as main content), title, and image), avoiding the area of the main object, show a little shadow on the right and bottom side, and uses fade effect.
Provided properties by this ToolTip.
Below are several custom properties of this tooltip:
AnimationSpeed property, to determine the fade effect takes time, in milliseconds.
AutoClose property, determine the length of the time tooltip will be displayed. This property is used when the
EnableAutoClose property is set to
EnableAutoClose property, if
True, the tooltip will be automatically closed when a period of time provided by
AutoClose property is passed, otherwise, the tooltip will be closed when
MouseDown event have occurred.
Location property, determine how the tooltip will be located.
CustomLocation property, custom location where the tool tip will be displayed, used when the
Location property is set to
OwnerDraw property, if
true, the tooltip's surface will be drawn by your code,
Draw events will be raised, otherwise, the tooltip surface will be drawn itself.
OwnerDrawBackground property, if
true, both background and surface of the tooltip will be drawn by your code,
Draw events will be raised, otherwise, the tooltip background will be drawn itself.
ToolTipLocation enumeration, this is the value of the
Auto, the tooltip location is automatically calculated in an appropriate location and avoiding the main object area.
MousePointer, the tooltip will be located around the mouse pointer.
CustomScreen, the tooltip will be located in specified location provided by
CustomLocation property on the screen.
CustomClient, the tooltip will be located in specified location provided by
CustomLocation property relative to the client area of the main object.
How Does It Work
To show a tooltip window, I create a window inherited from
Form. This window has
WS_EX_LAYERED on it extended window style.
Protected Overrides ReadOnly Property CreateParams() As System.Windows.Forms.CreateParams
Dim cp As CreateParams = MyBase.CreateParams
cp.ExStyle = cp.ExStyle Or WS_EX_LAYERED
After the window has been created, I use
SetWindowPos functions to display the window.
SetWindowPos(Me.Handle, HWND_TOPMOST, Me.Left, Me.Top, Me.Width, Me.Height, _
SWP_NOSIZE Or SWP_NOMOVE Or SWP_NOACTIVATE)
After the window has been created and displayed, now to draw the window. I use a bitmap as a canvas to draw the tooltip, and draw the bitmap to the screen on the window bounds.
Private Sub setBitmap(ByVal aBmp As Bitmap)
Dim screenDC As IntPtr = GetDC(IntPtr.Zero)
Dim memDC As IntPtr = CreateCompatibleDC(screenDC)
Dim hBitmap As IntPtr = IntPtr.Zero
Dim oldBitmap As IntPtr = IntPtr.Zero
hBitmap = aBmp.GetHbitmap(Color.FromArgb(0))
oldBitmap = SelectObject(memDC, hBitmap)
Dim size As Size = New Size(aBmp.Width, aBmp.Height)
Dim pointSource As Point = New Point(0, 0)
Dim topPos As Point = New Point(Me.Left, Me.Top)
Dim blend As BLENDFUNCTION = New BLENDFUNCTION
blend.BlendOp = AC_SRC_OVER
blend.BlendFlags = 0
blend.SourceConstantAlpha = 255
blend.AlphaFormat = AC_SRC_ALPHA
UpdateLayeredWindow(Me.Handle, screenDC, topPos, _
size, memDC, pointSource, 0, blend, ULW_ALPHA)
Catch ex As Exception
If hBitmap <> IntPtr.Zero Then
Creating Custom Shaped ToolTip
If you want to create a custom shaped ToolTip, you need to set
OwnerDrawBackground property of the tooltip to
True, and then, handle the
DrawBackground event raised by ToolTip.
Private Sub ToolTip1_Draw(ByVal sender As Object, ByVal e As Ai.Control.DrawEventArgs) _
Dim strFormat As StringFormat = New StringFormat
strFormat.LineAlignment = StringAlignment.Center
strFormat.Alignment = StringAlignment.Center
e.Graphics.DrawString("This is when OwnerDrawnBackground of _
the ToolTip is set to True", Me.Font, Brushes.Black, e.Rectangle, strFormat)
Private Sub ToolTip1_DrawBackground(ByVal sender As Object, _
ByVal e As Ai.Control.DrawEventArgs) Handles ToolTip1.DrawBackground
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias
e.Graphics.TextRenderingHint = Drawing.Text.TextRenderingHint.ClearTypeGridFit
Private Sub ToolTip1_Popup(ByVal sender As Object, _
ByVal e As Ai.Control.PopupEventArgs) Handles ToolTip1.Popup
e.Size = New Size(100, 100)
This code will produce a ToolTip like this:
Custom shaped tooltip by setting
OwnerDrawBackground property of the ToolTip to
- 3rd August, 2010: Initial post
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