05-10-12, 03:06 PM
كاتب الموضوع : silverlight
الكثير منا يستخدمون الكود التالي في برامجهم لكي يتخلصوا من الشكل التقليدي للفورمأو أيضا يمكن عمل نفس الشئ في مرحلة التصميم للفورم عن طريق تحديد هذه القيمة
وبالطبع عندما نستخدم الكود التالي قد نحتاج إلي إعطاء المستخدم الصلاحية لكي يتحكم في أبعاد الفورم مُثل تغيير إرتفاع الفورم أو عرض الفورم
كود :
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.FormBorderStyle = Windows.Forms.FormBorderStyle.None
End Subالكود التالي يوضح كيفية عمل ذلك باستخدام بعض دوال API التي هي معروفة للجميع تقريبا
والفكرة ببساطة تعتمد علي إستخدام الدالتان SendMessage و ReleaseCapture بالإضافة الي بعض الثوابت Constants التي يعتمد عليها نظام التشغيل والتي يتم إرسالها الي الفورم من داخل أحداث الماوس مع الوضع في الاعتبار تغيير شكل Cusor طبقا لمكان الماوس علي الفورم
والمثال التالي يوضح الفكرة
ولتنفيذ المثال افتح فورم ثم أكتب الكود بالشكل التالي
كود :
Imports System.Runtime.InteropServices
Public Class Form1
Private rect As Rectangle
Private m_mode As Modes = Modes.None
#Region " Enum & Constants "
Private Const WM_SYSCOMMAND As Integer = &H112
Private Const SC_DRAGMOVE As Integer = &HF012
Private Const SC_DRAGSIZE_N As Integer = &HF003
Private Const SC_DRAGSIZE_S As Integer = &HF006
Private Const SC_DRAGSIZE_E As Integer = &HF002
Private Const SC_DRAGSIZE_W As Integer = &HF001
Private Const SC_DRAGSIZE_NW As Integer = &HF004
Private Const SC_DRAGSIZE_NE As Integer = &HF005
Private Const SC_DRAGSIZE_SW As Integer = &HF007
Private Const SC_DRAGSIZE_SE As Integer = &HF008
Private Enum Modes
None
Bottom
BottomLeft
BottomRight
Left
Right
Top
TopLeft
TopRight
End Enum
#End Region
#Region " Methods "
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.FormBorderStyle = Windows.Forms.FormBorderStyle.None
End Sub
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
MyBase.OnPaint(e)
Dim rect As New Rectangle(0, 0, Me.Width, 29)
Using lgb As New Drawing2D.LinearGradientBrush(rect, Color.Cyan, Color.Blue, 90, True)
e.Graphics.FillRectangle(lgb, rect)
lgb.Dispose()
End Using
End Sub
Protected Overrides Sub OnMouseDown(ByVal e As System.Windows.Forms.MouseEventArgs)
'MyBase.OnMouseDown(e)
Dim hwnd As IntPtr = Me.Handle
Select Case m_mode
Case Modes.Bottom
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGSIZE_S, 0)
Exit Select
Case Modes.Right
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGSIZE_E, 0)
Exit Select
Case Modes.BottomRight
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGSIZE_SE, 0)
Exit Select
Case Modes.TopRight
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGSIZE_NE, 0)
Exit Select
Case Modes.Top
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGSIZE_N, 0)
Exit Select
Case Modes.TopLeft
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGSIZE_NW, 0)
Exit Select
Case Modes.Left
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGSIZE_W, 0)
Exit Select
Case Modes.BottomLeft
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGSIZE_SW, 0)
Exit Select
Case Modes.None
NativeAPI.ReleaseCapture(hwnd)
NativeAPI.SendMessage(hwnd, WM_SYSCOMMAND, SC_DRAGMOVE, 0)
Exit Select
End Select
End Sub
Protected Overrides Sub OnMouseLeave(ByVal e As System.EventArgs)
MyBase.OnMouseLeave(e)
Me.Cursor = Cursors.[Default]
End Sub
Protected Overrides Sub OnMouseMove(ByVal e As System.Windows.Forms.MouseEventArgs)
MyBase.OnMouseMove(e)
If (e.X < 5) AndAlso (e.Y < 5) Then
Me.Cursor = Cursors.SizeNWSE
m_mode = Modes.TopLeft
ElseIf (e.X < 5) AndAlso Math.Abs(e.Y - Me.ClientSize.Height) < 5 Then
Me.Cursor = Cursors.SizeNESW
m_mode = Modes.BottomLeft
ElseIf e.X < 5 Then
Me.Cursor = Cursors.SizeWE
m_mode = Modes.Left
ElseIf Math.Abs(e.X - Me.Width) < 5 AndAlso (e.Y < 5) Then
Me.Cursor = Cursors.SizeNESW
m_mode = Modes.TopRight
ElseIf Math.Abs(e.X - Me.Width) < 5 AndAlso Math.Abs(e.Y - Me.ClientSize.Height) < 5 Then
Me.Cursor = Cursors.SizeNWSE
m_mode = Modes.BottomRight
ElseIf Math.Abs(e.X - Me.Width) < 5 Then
Me.Cursor = Cursors.SizeWE
m_mode = Modes.Right
ElseIf Math.Abs(e.Y - Me.ClientSize.Height) < 5 Then
Me.Cursor = Cursors.SizeNS
m_mode = Modes.Bottom
ElseIf e.Y < 5 Then
Me.Cursor = Cursors.SizeNS
m_mode = Modes.Top
Else
Me.Cursor = Cursors.Default
m_mode = Modes.None
End If
End Sub
#End Region
#Region " Internal Class "
Private Class NativeAPI
<DllImport("USER32.DLL", EntryPoint:="SendMessage")> _
Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wParam As Integer, ByRef lParam As Integer) As Integer
End Function
<DllImport("USER32.DLL")> _
Public Shared Function ReleaseCapture(ByVal hwnd As IntPtr) As Integer
End Function
End Class
#End Region
End Classأخوكم عمر