VB.Net/Windows System/WndProc
Overrides WndProc(ByRef m As System.Windows.Forms.Message)
<source lang="vbnet"> Imports System Imports System.Runtime.InteropServices Imports System.Drawing Imports System.ruponentModel Imports System.Windows.Forms
Public Class MainClass
Shared Sub Main(ByVal args As String()) Dim myform As Form = New Form1() Application.Run(myform) End Sub
End Class
Public Class Form1
Public Structure Rect Public left As Integer Public top As Integer Public right As Integer Public bottom As Integer End Structure Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message) Const WM_SIZING As Long = &H214 Const WMSZ_LEFT As Integer = 1 Const WMSZ_RIGHT As Integer = 2 Const WMSZ_TOP As Integer = 3 Const WMSZ_TOPLEFT As Integer = 4 Const WMSZ_TOPRIGHT As Integer = 5 Const WMSZ_BOTTOM As Integer = 6 Const WMSZ_BOTTOMLEFT As Integer = 7 Const WMSZ_BOTTOMRIGHT As Integer = 8 Static fixed_aspect_ratio As Double = 0 Dim new_aspect_ratio As Double If m.Msg = WM_SIZING And m.HWnd.Equals(Me.Handle) Then Dim r As Rect r = DirectCast( _ Marshal.PtrToStructure(m.LParam, GetType(Rect)), _ Rect) Dim width As Double = r.right - r.left Dim height As Double = r.bottom - r.top new_aspect_ratio = height / width If fixed_aspect_ratio = 0 Then fixed_aspect_ratio = new_aspect_ratio End If If fixed_aspect_ratio <> new_aspect_ratio Then If m.WParam.ToInt32 = WMSZ_TOPLEFT Or _ m.WParam.ToInt32 = WMSZ_TOPRIGHT Or _ m.WParam.ToInt32 = WMSZ_BOTTOMLEFT Or _ m.WParam.ToInt32 = WMSZ_BOTTOMRIGHT _ Then If new_aspect_ratio > fixed_aspect_ratio Then width = height / fixed_aspect_ratio Else height = width * fixed_aspect_ratio End If ElseIf m.WParam.ToInt32 = WMSZ_LEFT Or _ m.WParam.ToInt32 = WMSZ_RIGHT _ Then height = width * fixed_aspect_ratio ElseIf m.WParam.ToInt32 = WMSZ_TOP Or _ m.WParam.ToInt32 = WMSZ_BOTTOM _ Then width = height / fixed_aspect_ratio End If If m.WParam.ToInt32 = WMSZ_TOP Or _ m.WParam.ToInt32 = WMSZ_TOPLEFT Or _ m.WParam.ToInt32 = WMSZ_TOPRIGHT _ Then r.top = r.bottom - CInt(height) Else r.bottom = r.top + CInt(height) End If If m.WParam.ToInt32 = WMSZ_LEFT Or _ m.WParam.ToInt32 = WMSZ_TOPLEFT Or _ m.WParam.ToInt32 = WMSZ_BOTTOMLEFT _ Then r.left = r.right - CInt(width) Else r.right = r.left + CInt(width) End If Marshal.StructureToPtr(r, m.LParam, True) End If End If MyBase.WndProc(m) End Sub
End Class <Global.Microsoft.VisualBasic.rupilerServices.DesignerGenerated()> _ Partial Public Class Form1
Inherits System.Windows.Forms.Form "Form overrides dispose to clean up the component list. <System.Diagnostics.DebuggerNonUserCode()> _ Protected Overrides Sub Dispose(ByVal disposing As Boolean) If disposing AndAlso components IsNot Nothing Then components.Dispose() End If MyBase.Dispose(disposing) End Sub "Required by the Windows Form Designer Private components As System.ruponentModel.IContainer "NOTE: The following procedure is required by the Windows Form Designer "It can be modified using the Windows Form Designer. "Do not modify it using the code editor. <System.Diagnostics.DebuggerStepThrough()> _ Private Sub InitializeComponent() Me.SuspendLayout() " "Form1 " Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!) Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font Me.ClientSize = New System.Drawing.Size(292, 273) Me.Name = "Form1" Me.Text = "FixedAspectRatio" Me.ResumeLayout(False) End Sub
End Class
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