INTRODUCTION:
I'm using a custom messagebox class which was originally written by @Hans Passant here: Winforms-How can I make MessageBox appear centered on MainForm?
(The modified version that I'm using is at bottom of this question)
The custom messagebox can receive a custom text font to display it.
This is an usage example:
Using New CenteredMessageBox(Me, _
New Font(New FontFamily("Lucida Console"), 16, FontStyle.Bold))
MessageBox.Show("Test Text", "Test Title", MessageBoxButtons.YesNo, MessageBoxIcon.Question)
End Using
THE PROBLEM:
All the contents of the window need to be resized/positioned manually, if not, the text will de displayed cropped like this:
And this is the result If I use bigger fonts (I've resized the text control):
So I need to calculate which position and size would have the elements realatively to the font size, to resize the window and to positionate the buttons, and that is what I'm asking for. How I can do it? I would need more than a just formula 'cause mathematics i do not do much well.
THE ELEMENTS:
I have these elements in mind:
- The Messagebox text-font size.
- The Messagebox static control that contains and displays the text.
- The Messagebox button(s) (which can be a combination of 1 button, 2 buttons, or 3 buttons, with different default positions)
- The Messagebox Window Form which contains all these elements.
Button(s) variables:
- If only is 1 buton in messagebox window (ex: 'Ok') it will be alligned to middle, but if they are 3 buttons (ex: 'AbortRetryIgnore') then the first button will be alligned to down left corner, the second button to middle and the last button to the right corner, I think there is no need to explain this 'cause all knows how the msgbox displays their buttons.
I'm not an arithmetic guru, so forgive me if I miss some necessary values, but I think that these would be the necessary values/variables in the code to work with:
Dim Text_width As Integer = 0
Dim Text_height As Integer = 0
Dim Text_Container_width As Integer = 0
Dim Text_Container_height As Integer = 0
' Don't calculate the exact size of messagebox window,
' just I think only needs to sum an extra size to a default messagebox rectangle
Dim Messagebox_window_extra_width As Integer = 0
Dim Messageboxwindow_extra_height As Integer = 0
' This represents the first button,
' in a messagebox button combination of 1, 2, or 3 buttons,
' this button could be displayed alligned at bottom-middle (as unique button),
' or could be alligned at bottom-left (as the first of 2 of 3 button combination).
Dim Button_1_Pos_X As Integer = 0
Dim Button_1_Pos_Y As Integer = 0
' This button represents the second button
' in a messagebox button combination of 2 or 3 buttons,
' the buton could exist or could not
' and could be displayed alligned at bottom-middle (in the middle of 3 buttons),
' this button could be displayed alligned at bottom-right (as second and last button).
Dim Button_2_Pos_X As Integer = 0
Dim Button_2_Pos_Y As Integer = 0
' This button represents the third button
' a messagebox button combination of 2 or 3 buttons,
' the buton could exist or could not
' and could be displayed alligned at bottom-right (as third and last button).
Dim Button_3_Pos_X As Integer = 0
Dim Button_3_Pos_Y As Integer = 0
This is what I could did by myself, I've been testing to store the messagebox button elements in this way:
Dim button_Ok As IntPtr = GetDlgItem(hWnd, 1) ' The 'Ok' button.
Dim button_Cancel As IntPtr = GetDlgItem(hWnd, 2) ' the 'Cancel' button.
Dim button_Abort As IntPtr = GetDlgItem(hWnd, 3) ' the 'Abort' button.
Dim button_Retry As IntPtr = GetDlgItem(hWnd, 4) ' the 'Retry' button.
Dim button_Ignore As IntPtr = GetDlgItem(hWnd, 5) ' the 'Ignore' button.
Dim button_Yes As IntPtr = GetDlgItem(hWnd, 6) ' the 'Yes' button.
Dim button_No As IntPtr = GetDlgItem(hWnd, 7) ' the 'NO' button.
(Their always have the same Item index no matter the messagebox buton combination)
To resize the messagebox window I can use the MoveWindow API like this:
' This is to resize and positionate the messagebox window
MoveWindow(hWnd, _
frmRect.Left + (frmRect.Width - dlgRect.Right + dlgRect.Left) \ 2, _
frmRect.Top + (frmRect.Height - dlgRect.Bottom + dlgRect.Top) \ 2, _
(dlgRect.Right - dlgRect.Left) + Messagebox_window_extra_width, _
(dlgRect.Bottom - dlgRect.Top) + Messagebox_window_extra_height, True)
And to resize the rest elements (text container, buttons), after resizing the messagebox form then I can use the SetWindowPos API like this:
' Text container:
SetWindowPos(hText, 0, 70, 30, 1920, 1080, 0) ' Values are not perfect calculated but works fine
' Messagebox buttons:
' SetWindowPos(button_Ok, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Cancel, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Abort, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Retry, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Ignore, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Yes, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_No, 0, 0, 0, 0, 0, 0)
THE MESSAGEBOX CLASS
Here is messed up all the things that I've mentioned before:
' [ Centered MessageBox ]
'
' The author of the original code is Hans Passant: https://stackoverflow.com/questions/2576156/winforms-how-can-i-make-messagebox-appear-centered-on-mainform
'
' Examples :
'
' Using New CenteredMessageBox(Me, New Font(New FontFamily("Lucida Console"), Font.SizeInPoints, FontStyle.Bold))
' MessageBox.Show("Test Text", "Test Title", MessageBoxButtons.OK, MessageBoxIcon.Information)
' End Using
#Region " Centered MessageBox Class"
Imports System.Drawing
Imports System.Runtime.InteropServices
Imports System.Text
Imports System.Windows.Forms
Class CenteredMessageBox : Implements IDisposable
Private mTries As Integer = 0
Private mOwner As Form
Private mFont As Font
Dim Text_width As Integer = 0
Dim Text_height As Integer = 0
Dim Text_Container_width As Integer = 0
Dim Text_Container_height As Integer = 0
Dim Messagebox_window_extra_width As Integer = 0
Dim Messagebox_window_extra_height As Integer = 0
Dim Button_1_Pos_X As Integer = 0 ' "OK" Button
Dim Button_1_Pos_Y As Integer = 0 ' "OK" Button
Dim Button_2_Pos_X As Integer = 0 ' This button could not exist
Dim Button_2_Pos_Y As Integer = 0 ' This button could not exist
Dim Button_3_Pos_X As Integer = 0 ' This button could not exist
Dim Button_3_Pos_Y As Integer = 0 ' This button could not exist
' P/Invoke declarations
Private Const WM_SETFONT As Integer = &H30
Private Const WM_GETFONT As Integer = &H31
Private Delegate Function EnumThreadWndProc(hWnd As IntPtr, lp As IntPtr) As Boolean
<DllImport("user32.dll")> _
Private Shared Function EnumThreadWindows(tid As Integer, callback As EnumThreadWndProc, lp As IntPtr) As Boolean
End Function
<DllImport("kernel32.dll")> _
Private Shared Function GetCurrentThreadId() As Integer
End Function
<DllImport("user32.dll")> _
Private Shared Function GetClassName(hWnd As IntPtr, buffer As StringBuilder, buflen As Integer) As Integer
End Function
<DllImport("user32.dll")> _
Private Shared Function GetDlgItem(hWnd As IntPtr, item As Integer) As IntPtr
End Function
<DllImport("user32.dll")> _
Private Shared Function SendMessage(hWnd As IntPtr, msg As Integer, wp As IntPtr, lp As IntPtr) As IntPtr
End Function
<DllImport("user32.dll")> _
Shared Function GetWindowRect(hWnd As IntPtr, ByRef rc As RECT) As Boolean
End Function
<DllImport("user32.dll")> _
Shared Function MoveWindow(hWnd As IntPtr, x As Integer, y As Integer, w As Integer, h As Integer, repaint As Boolean) As Boolean
End Function
Structure RECT
Public Left As Integer
Public Top As Integer
Public Right As Integer
Public Bottom As Integer
End Structure
Friend Declare Function SetWindowPos Lib "user32" (ByVal hwnd As IntPtr, ByVal hWndInsertAfter As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal cx As Integer, ByVal cy As Integer, ByVal wFlags As UInt32) As Boolean
Public Sub New(owner As Form, Optional Custom_Font As Font = Nothing)
mOwner = owner
mFont = Custom_Font
owner.BeginInvoke(New MethodInvoker(AddressOf findDialog))
End Sub
Private Sub findDialog()
' Enumerate windows to find the message box
If mTries < 0 Then
Return
End If
Dim callback As New EnumThreadWndProc(AddressOf checkWindow)
If EnumThreadWindows(GetCurrentThreadId(), callback, IntPtr.Zero) Then
If System.Threading.Interlocked.Increment(mTries) < 10 Then
mOwner.BeginInvoke(New MethodInvoker(AddressOf findDialog))
End If
End If
End Sub
Private Function checkWindow(hWnd As IntPtr, lp As IntPtr) As Boolean
' Checks if <hWnd> is a dialog
Dim sb As New StringBuilder(260)
GetClassName(hWnd, sb, sb.Capacity)
If sb.ToString() <> "#32770" Then Return True
' Got it, get the STATIC control that displays the text
Dim hText As IntPtr = GetDlgItem(hWnd, &HFFFF)
' Get the messagebox button elements
Dim button_Ok As IntPtr = GetDlgItem(hWnd, 1) ' The 'Ok' button.
Dim button_Cancel As IntPtr = GetDlgItem(hWnd, 2) ' the 'Cancel' button.
Dim button_Abort As IntPtr = GetDlgItem(hWnd, 3) ' the 'Abort' button.
Dim button_Retry As IntPtr = GetDlgItem(hWnd, 4) ' the 'Retry' button.
Dim button_Ignore As IntPtr = GetDlgItem(hWnd, 5) ' the 'Ignore' button.
Dim button_Yes As IntPtr = GetDlgItem(hWnd, 6) ' the 'Yes' button.
Dim button_No As IntPtr = GetDlgItem(hWnd, 7) ' the 'NO' button.
Dim frmRect As New Rectangle(mOwner.Location, mOwner.Size)
Dim dlgRect As RECT
GetWindowRect(hWnd, dlgRect)
If hText <> IntPtr.Zero Then
If mFont Is Nothing Then
' Get the current font
mFont = Font.FromHfont(SendMessage(hText, WM_GETFONT, IntPtr.Zero, IntPtr.Zero))
End If
SendMessage(hText, WM_SETFONT, mFont.ToHfont(), New IntPtr(1))
' Just here is an empty space where I can test some operations:
'
' Messagebox_window_extra_width = (mFont.Height \ mFont.Size) + (dlgRect.Right)
' Messagebox_window_extra_height = mFont.Height +
' This is to resize and positionate the messagebox window:
MoveWindow(hWnd, _
frmRect.Left + (frmRect.Width - dlgRect.Right + dlgRect.Left) \ 2, _
frmRect.Top + (frmRect.Height - dlgRect.Bottom + dlgRect.Top) \ 2, _
(dlgRect.Right - dlgRect.Left) + Messagebox_window_extra_width, _
(dlgRect.Bottom - dlgRect.Top) + Messagebox_window_extra_height, True)
' And this is to resize and positionate the rest elements:
'
' Text container:
SetWindowPos(hText, 0, 70, 30, 1920, 1080, 0)
'
' Messagebox buttons:
' SetWindowPos(button_Ok, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Cancel, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Abort, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Retry, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Ignore, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Yes, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_No, 0, 0, 0, 0, 0, 0)
End If
' Done
Return False
End Function
Public Sub Dispose() Implements IDisposable.Dispose
mTries = -1
mOwner = Nothing
If mFont IsNot Nothing Then mFont.Dispose()
End Sub
End Class
#End Region
UPDATE
This is what I get trying to use @Grahamvs solution:
Using New CenteredMessageBox(Me, New Font(New FontFamily("Lucida Console"), Font.SizeInPoints, FontStyle.Bold))
MessageBox.Show("Test Text", "Test Title", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Using
Grahamvs
This worked for me:
I changed:
<DllImport("user32.dll")> _
Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wp As IntPtr, ByVal lp As IntPtr) As IntPtr
End Function
to
Declare Auto Function SendMessage Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
and add (after SendMessage(hText, WM_SETFONT, mFont.ToHfont(), New IntPtr(1)))
' Get text
Dim WM_GETTEXT As Integer = &HD
' Alloc memory for the buffer that recieves the text
Dim Hndl As IntPtr = Marshal.AllocHGlobal(200)
' Send The WM_GETTEXT Message
Dim NumText As Integer = SendMessage(hText, WM_GETTEXT, 200, Hndl)
' Copy the characters from the unmanaged memory to a managed string
Dim MSGText As String = Marshal.PtrToStringUni(Hndl)
' Measure the text
Dim TextSize As SizeF
Using G As Graphics = mOwner.CreateGraphics
TextSize = G.MeasureString(MSGText & "MMM", mFont)
End Using
and changed MoveWindow to:
MoveWindow(hWnd, frmRect.Left + (frmRect.Width - dlgRect.Right + dlgRect.Left) \ 2, frmRect.Top + (frmRect.Height - dlgRect.Bottom + dlgRect.Top) \ 2, CInt(TextSize.Width) + Messagebox_window_extra_width, (dlgRect.Bottom - dlgRect.Top) + Messagebox_window_extra_height, True)
Hope this helps
Edit: Here is the full code
' [ Centered MessageBox ]
'
' The author of the original code is Hans Passant: http://stackoverflow.com/questions/2576156/winforms-how-can-i-make-messagebox-appear-centered-on-mainform
'
' Examples :
'
' Using New CenteredMessageBox(Me, New Font(New FontFamily("Lucida Console"), Font.SizeInPoints, FontStyle.Bold))
' MessageBox.Show("Test Text", "Test Title", MessageBoxButtons.OK, MessageBoxIcon.Information)
' End Using
#Region " Centered MessageBox Class"
Imports System.Drawing
Imports System.Runtime.InteropServices
Imports System.Text
Imports System.Windows.Forms
Class CenteredMessageBox : Implements IDisposable
Private mTries As Integer = 0
Private mOwner As Form
Private mFont As Font
Dim Text_width As Integer = 0
Dim Text_height As Integer = 0
Dim Text_Container_width As Integer = 0
Dim Text_Container_height As Integer = 0
Dim Messagebox_window_extra_width As Integer = 0
Dim Messagebox_window_extra_height As Integer = 0
Dim Button_1_Pos_X As Integer = 0 ' "OK" Button
Dim Button_1_Pos_Y As Integer = 0 ' "OK" Button
Dim Button_2_Pos_X As Integer = 0 ' This button could not exist
Dim Button_2_Pos_Y As Integer = 0 ' This button could not exist
Dim Button_3_Pos_X As Integer = 0 ' This button could not exist
Dim Button_3_Pos_Y As Integer = 0 ' This button could not exist
' P/Invoke declarations
Private Const WM_SETFONT As Integer = &H30
Private Const WM_GETFONT As Integer = &H31
Private Delegate Function EnumThreadWndProc(ByVal hWnd As IntPtr, ByVal lp As IntPtr) As Boolean
<DllImport("user32.dll")> _
Private Shared Function EnumThreadWindows(ByVal tid As Integer, ByVal callback As EnumThreadWndProc, ByVal lp As IntPtr) As Boolean
End Function
<DllImport("kernel32.dll")> _
Private Shared Function GetCurrentThreadId() As Integer
End Function
<DllImport("user32.dll")> _
Private Shared Function GetClassName(ByVal hWnd As IntPtr, ByVal buffer As StringBuilder, ByVal buflen As Integer) As Integer
End Function
<DllImport("user32.dll")> _
Private Shared Function GetDlgItem(ByVal hWnd As IntPtr, ByVal item As Integer) As IntPtr
End Function
'<DllImport("user32.dll")> _
'Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wp As IntPtr, ByVal lp As IntPtr) As IntPtr
'End Function
<DllImport("user32.dll")> _
Shared Function GetWindowRect(ByVal hWnd As IntPtr, ByRef rc As RECT) As Boolean
End Function
<DllImport("user32.dll")> _
Shared Function MoveWindow(ByVal hWnd As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal w As Integer, ByVal h As Integer, ByVal repaint As Boolean) As Boolean
End Function
Declare Auto Function SendMessage Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
Structure RECT
Public Left As Integer
Public Top As Integer
Public Right As Integer
Public Bottom As Integer
End Structure
Friend Declare Function SetWindowPos Lib "user32" (ByVal hwnd As IntPtr, ByVal hWndInsertAfter As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal cx As Integer, ByVal cy As Integer, ByVal wFlags As UInt32) As Boolean
Public Sub New(ByVal owner As Form, Optional ByVal Custom_Font As Font = Nothing)
mOwner = owner
mFont = Custom_Font
owner.BeginInvoke(New MethodInvoker(AddressOf findDialog))
End Sub
Private Sub findDialog()
' Enumerate windows to find the message box
If mTries < 0 Then
Return
End If
Dim callback As New EnumThreadWndProc(AddressOf checkWindow)
If EnumThreadWindows(GetCurrentThreadId(), callback, IntPtr.Zero) Then
If System.Threading.Interlocked.Increment(mTries) < 10 Then
mOwner.BeginInvoke(New MethodInvoker(AddressOf findDialog))
End If
End If
End Sub
Private Function checkWindow(ByVal hWnd As IntPtr, ByVal lp As IntPtr) As Boolean
' Checks if <hWnd> is a dialog
Dim sb As New StringBuilder(260)
GetClassName(hWnd, sb, sb.Capacity)
If sb.ToString() <> "#32770" Then Return True
' Got it, get the STATIC control that displays the text
Dim hText As IntPtr = GetDlgItem(hWnd, &HFFFF)
' Get the messagebox button elements
Dim button_Ok As IntPtr = GetDlgItem(hWnd, 1) ' The 'Ok' button.
Dim button_Cancel As IntPtr = GetDlgItem(hWnd, 2) ' the 'Cancel' button.
Dim button_Abort As IntPtr = GetDlgItem(hWnd, 3) ' the 'Abort' button.
Dim button_Retry As IntPtr = GetDlgItem(hWnd, 4) ' the 'Retry' button.
Dim button_Ignore As IntPtr = GetDlgItem(hWnd, 5) ' the 'Ignore' button.
Dim button_Yes As IntPtr = GetDlgItem(hWnd, 6) ' the 'Yes' button.
Dim button_No As IntPtr = GetDlgItem(hWnd, 7) ' the 'NO' button.
Dim frmRect As New Rectangle(mOwner.Location, mOwner.Size)
Dim dlgRect As RECT
GetWindowRect(hWnd, dlgRect)
If hText <> IntPtr.Zero Then
If mFont Is Nothing Then
' Get the current font
mFont = Font.FromHfont(SendMessage(hText, WM_GETFONT, IntPtr.Zero, IntPtr.Zero))
End If
SendMessage(hText, WM_SETFONT, mFont.ToHfont(), New IntPtr(1))
' Get text
Dim WM_GETTEXT As Integer = &HD
' Alloc memory for the buffer that recieves the text
Dim Hndl As IntPtr = Marshal.AllocHGlobal(200)
' Send The WM_GETTEXT Message
Dim NumText As Integer = SendMessage(hText, WM_GETTEXT, 200, Hndl)
' Copy the characters from the unmanaged memory to a managed string
Dim MSGText As String = Marshal.PtrToStringUni(Hndl)
' Measure the text
Dim TextSize As SizeF
Using G As Graphics = mOwner.CreateGraphics
TextSize = G.MeasureString(MSGText & "MMM", mFont)
End Using
' Just here is an empty space where I can test some operations:
'
' Messagebox_window_extra_width = (mFont.Height \ mFont.Size) + (dlgRect.Right)
' Messagebox_window_extra_height = mFont.Height +
' This is to resize and positionate the messagebox window:
'MoveWindow(hWnd, frmRect.Left + (frmRect.Width - dlgRect.Right + dlgRect.Left) \ 2, frmRect.Top + (frmRect.Height - dlgRect.Bottom + dlgRect.Top) \ 2, _
' (dlgRect.Right - dlgRect.Left) + Messagebox_window_extra_width, (dlgRect.Bottom - dlgRect.Top) + Messagebox_window_extra_height, True)
MoveWindow(hWnd, frmRect.Left + (frmRect.Width - dlgRect.Right + dlgRect.Left) \ 2, frmRect.Top + (frmRect.Height - dlgRect.Bottom + dlgRect.Top) \ 2, Math.Max(CInt(TextSize.Width), 200) + Messagebox_window_extra_width, (dlgRect.Bottom - dlgRect.Top) + Messagebox_window_extra_height, True)
' And this is to resize and positionate the rest elements:
'
' Text container:
SetWindowPos(hText, 0, 70, 30, 1920, 1080, 0)
'
' Messagebox buttons:
' SetWindowPos(button_Ok, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Cancel, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Abort, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Retry, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Ignore, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_Yes, 0, 0, 0, 0, 0, 0)
' SetWindowPos(button_No, 0, 0, 0, 0, 0, 0)
End If
' Done
Return False
End Function
Public Sub Dispose() Implements IDisposable.Dispose
mTries = -1
mOwner = Nothing
If mFont IsNot Nothing Then mFont.Dispose()
End Sub
End Class
#End Region
来源：https://stackoverflow.com/questions/19397549/which-is-the-mathematic-formula-to-calculate-the-size-and-positions-for-this-win