Question

我想要做的是打开ColorDialog时，在Colordialog的“完全打开”模式下获取时间选择颜色。

例如在这张图片中，我有一个白色的彩色图片框，并且选择了“红色”颜色打开了ColorDialog，我想要的是将图片框背景颜色更改为所选颜色（红色）而不按“确定”按钮确认ColorDialog并获得Color结果...

enter image description here

这可能与默认的ColorDialog有关吗？

这是我尝试过的：

Public Class Form1

    Dim WithEvents PicBox As New PictureBox
    Dim ColorDlg As New ColorDialog

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        PicBox.BackColor = Color.Blue
        ColorDlg.FullOpen = True
        Me.Controls.Add(PicBox)
    End Sub

    Private Sub PicBox_Click(sender As Object, e As EventArgs) Handles PicBox.Click
        ColorDlg.Color = sender.backcolor
        While Not ColorDlg.ShowDialog() = Windows.Forms.DialogResult.OK
            sender.BackColor = ColorDlg.Color
        End While
        ' sender.BackColor = ColorDlg.Color
    End Sub

End Class

Answer 1

免责声明：仅仅因为我们可以，并不代表我们应该这样做！

此示例专门用于在ColorDialog模式下使用FullOpen。它依赖于以下事实：对话框中的“红色：”，“绿色：”和“蓝色：”Edit控件在用户更改颜色时实时更新，并且事实是每次更新这些控件时都会发送WM_CTLCOLOREDIT（这也适用于手动输入这些值的时间）。每次我们想要使用它时，我们必须创建一个MyColorDialog的新实例，以便这些控件的窗口句柄是正确的。

以下WindowsEnumerator课程基于Bob的（TheLearnedOne）作品here。

*我也Idle_Mind在专家交流处结束了。

这是在VS2010 Premium的Win8 Pro上测试的。如果在其他版本的Windows中需要对ColorDialog进行任何更改，我不会这样做：

Public Class Form1

    Private WithEvents PicBox As New PictureBox
    Private WithEvents ColorDlg As MyColorDialog = Nothing

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        PicBox.BackColor = Color.Blue
        Me.Controls.Add(PicBox)
    End Sub

    Private Sub PicBox_Click(sender As Object, e As EventArgs) Handles PicBox.Click
        ColorDlg = New MyColorDialog
        ColorDlg.Color = sender.backcolor
        If ColorDlg.ShowDialog() = Windows.Forms.DialogResult.OK Then
            sender.BackColor = ColorDlg.Color
        End If
        ColorDlg = Nothing
    End Sub

    Private Sub ColorDlg_CurrentColor(c As System.Drawing.Color) Handles ColorDlg.CurrentColor
        PicBox.BackColor = c
    End Sub

End Class

Public Class MyColorDialog
    Inherits ColorDialog

    Public Event CurrentColor(ByVal c As Color)

    Private Const GA_ROOT As Integer = 2
    Private Const WM_CTLCOLOREDIT As Integer = &H133

    Public Declare Function GetAncestor Lib "user32.dll" _
        (ByVal hWnd As IntPtr, ByVal gaFlags As Integer) As IntPtr

    Private EditWindows As List(Of ApiWindow) = Nothing

    Public Sub New()
        Me.FullOpen = True
    End Sub

    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Protected Overrides Function HookProc(ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
        Select Case msg
            Case WM_CTLCOLOREDIT
                If IsNothing(EditWindows) Then
                    Dim mainWindow As IntPtr = GetAncestor(hWnd, GA_ROOT)
                    If Not mainWindow.Equals(IntPtr.Zero) Then
                        EditWindows = New List(Of ApiWindow)((New WindowsEnumerator).GetChildWindows(mainWindow, "Edit"))
                    End If
                End If

                If Not IsNothing(EditWindows) AndAlso EditWindows.Count = 6 Then
                    Dim strRed As String = WindowsEnumerator.WindowText(EditWindows(3).hWnd)
                    Dim strGreen As String = WindowsEnumerator.WindowText(EditWindows(4).hWnd)
                    Dim strBlue As String = WindowsEnumerator.WindowText(EditWindows(5).hWnd)

                    Dim Red, Green, Blue As Integer
                    If Integer.TryParse(strRed, Red) Then
                        If Integer.TryParse(strGreen, Green) Then
                            If Integer.TryParse(strBlue, Blue) Then
                                RaiseEvent CurrentColor(Color.FromArgb(Red, Green, Blue))
                            End If
                        End If
                    End If
                End If
        End Select

        Return MyBase.HookProc(hWnd, msg, wParam, lParam)
    End Function

End Class

Public Class ApiWindow
    Public hWnd As IntPtr
    Public ClassName As String
    Public MainWindowTitle As String
End Class

Public Class WindowsEnumerator

    Private Delegate Function EnumCallBackDelegate(ByVal hwnd As IntPtr, ByVal lParam As Integer) As Integer

    Private Declare Function EnumWindows Lib "user32" _
        (ByVal lpEnumFunc As EnumCallBackDelegate, ByVal lParam As Integer) As Integer

    Private Declare Function EnumChildWindows Lib "user32" _
        (ByVal hWndParent As IntPtr, ByVal lpEnumFunc As EnumCallBackDelegate, ByVal lParam As Integer) As Integer

    Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" _
        (ByVal hwnd As IntPtr, ByVal lpClassName As System.Text.StringBuilder, ByVal nMaxCount As Integer) As Integer

    Private Declare Function IsWindowVisible Lib "user32" (ByVal hwnd As IntPtr) As Integer

    Private Declare Function GetParent Lib "user32" (ByVal hwnd As IntPtr) As Integer

    Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
        (ByVal hwnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer

    Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
        (ByVal hwnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As System.Text.StringBuilder) As Integer

    Private _listChildren As New List(Of ApiWindow)
    Private _listTopLevel As New List(Of ApiWindow)

    Private _topLevelClass As String = String.Empty
    Private _childClass As String = String.Empty

    Public Overloads Function GetTopLevelWindows() As ApiWindow()
        EnumWindows(AddressOf EnumWindowProc, &H0)
        Return _listTopLevel.ToArray
    End Function

    Public Overloads Function GetTopLevelWindows(ByVal className As String) As ApiWindow()
        _topLevelClass = className
        Return Me.GetTopLevelWindows()
    End Function

    Public Overloads Function GetChildWindows(ByVal hwnd As Int32) As ApiWindow()
        _listChildren.Clear()
        EnumChildWindows(hwnd, AddressOf EnumChildWindowProc, &H0)
        Return _listChildren.ToArray
    End Function

    Public Overloads Function GetChildWindows(ByVal hwnd As Int32, ByVal childClass As String) As ApiWindow()
        _childClass = childClass
        Return Me.GetChildWindows(hwnd)
    End Function

    Private Function EnumWindowProc(ByVal hwnd As Int32, ByVal lParam As Int32) As Int32
        If GetParent(hwnd) = 0 AndAlso IsWindowVisible(hwnd) Then
            Dim window As ApiWindow = GetWindowIdentification(hwnd)
            If _topLevelClass.Length = 0 OrElse window.ClassName.ToLower() = _topLevelClass.ToLower() Then
                _listTopLevel.Add(window)
            End If
        End If
        Return 1
    End Function

    Private Function EnumChildWindowProc(ByVal hwnd As Int32, ByVal lParam As Int32) As Int32
        Dim window As ApiWindow = GetWindowIdentification(hwnd)
        If _childClass.Length = 0 OrElse window.ClassName.ToLower() = _childClass.ToLower() Then
            _listChildren.Add(window)
        End If
        Return 1
    End Function

    Private Function GetWindowIdentification(ByVal hwnd As Integer) As ApiWindow
        Dim classBuilder As New System.Text.StringBuilder(64)
        GetClassName(hwnd, classBuilder, 64)

        Dim window As New ApiWindow
        window.ClassName = classBuilder.ToString()
        window.MainWindowTitle = WindowText(hwnd)
        window.hWnd = hwnd
        Return window
    End Function

    Public Shared Function WindowText(ByVal hwnd As IntPtr) As String
        Const W_GETTEXT As Integer = &HD
        Const W_GETTEXTLENGTH As Integer = &HE

        Dim SB As New System.Text.StringBuilder
        Dim length As Integer = SendMessage(hwnd, W_GETTEXTLENGTH, 0, 0)
        If length > 0 Then
            SB = New System.Text.StringBuilder(length + 1)
            SendMessage(hwnd, W_GETTEXT, SB.Capacity, SB)
        End If
        Return SB.ToString
    End Function

End Class

在确认对话框之前，ColorDialog仍然打开时获取颜色属性？

1 个答案: