如何解决此问题:参数无效 [英] How to solve this problem : Parameter is not valid

问题描述

大家好.

首先，对不起我的英语不好.

使用:
Visual Studio 2005
Visual Basic.NET

我正在开发一个小型Media Player，该应用程序可以播放最流行的音乐格式，并可以查看某些图像格式.

我有继承自System.Windows.Forms.Control
的自定义控件(称为BtnEx)
我想解决下一个问题:
ArgumentException:参数无效

此错误发生在我的代码的下一行:

Hello everyone.

First of all, sorry for my bad english.

Using:
Visual Studio 2005
Visual Basic.NET

I''m developing a small Media Player, an application which can play most popular music formats, and can view some image formats.

I have my custom control (called BtnEx) that inherits System.Windows.Forms.Control

I want to solve the next problem:
ArgumentException : Parameter is not valid

This error occurs in the next line of my code:

Dim CImg as New Bitmap (PImg, e.ClipRectangle.Width - 2, e.ClipRectangle.Height - 2)

但是仅在设计模式下，而不是在我运行程序时(通过按F5按钮).


当我构建项目时，一切正常，直到按我的自定义控件为止(用于拖动和选择).这一切都是在设计模式(IDE)中发生的
一个"X"图像而不是控件的图像出现，并且Visual Studio显示带有错误描述的MessageBox.在该说明中，我可以读取发生错误的代码行. (ArgumentException发生在文件"C:\ ... \ BtnEx.vb"行:67中.

当我再次构建项目时，红色的"X"图像消失了，一切都很好，但是正如我所说，当我单击控件时，就会发生异常.

我在 OnPaint 子程序中调用此过程.

这是OnPaint子目录:

But only in Design Mode, not when I run my program (by pressing the F5 button).


When i build my project all works fine until I press my custom control (For dragging and selecting). Thats all happening in Design Mode (IDE)
A "X" image is appearing instead of Control''s Image, and Visual Studio shows MessageBox with error description. In that description I can read in which line of code error occurs. (ArgumentException occured in file "C:\ ... \BtnEx.vb" line: 67.

When I Build my project (again) the red "X" image dissapears and all loks fine, but as I said, when i click on control that exception occurs.

I''m calling this procedure in OnPaint Sub.

This is the OnPaint Sub:

Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
         MyBase.OnPaint(e)
            If PImg Is Nothing = False Then
            ' Error is in the next line:
                        Dim CImg As New Bitmap(PImg, e.ClipRectangle.Width - 2, e.ClipRectangle.Height - 2)
            ' When I run this program (F5) then no error is occured.
If Me.Enabled = True Then
                Select Case MS
                    Case EMouseState.MouseHover
                        ' HighLight The Image
                        IMGA.SetGamma(0.57#)
                        e.Graphics.DrawImage(CImg, CRect, 0, 0, CRect.Width, CRect.Height, GraphicsUnit.Pixel, IMGA)
                    Case EMouseState.MouseDown
                        ' Make Image darker
                        IMGA.SetGamma(1.77#)
                        e.Graphics.DrawImage(CImg, CRect, 0, 0, CRect.Width, CRect.Height, GraphicsUnit.Pixel, IMGA)
                    Case EMouseState.MouseUp
                        If InB = True Then ' If mouse is on it.
                            IMGA.SetGamma(0.57#)
                            e.Graphics.DrawImage(CImg, CRect, 0, 0, CRect.Width, CRect.Height, GraphicsUnit.Pixel, IMGA)
                        Else
                            e.Graphics.DrawImage(CImg, CRect)
                        End If
                    Case EMouseState.MouseLeave
                        e.Graphics.DrawImage(CImg, CRect)
                End Select
                Else
                    ' Method used by MicroSoft to paint controls disabled.
                    ControlPaint.DrawImageDisabled(e.Graphics, CImg, 1, 1, Color.Transparent)
            End If
        End If
    End Sub

当我使用数字代替e.ClipRectangle.Width或e.ClipRectangle.Height时，它运行良好.

例子:

When I use numbers instead e.ClipRectangle.Width or e.ClipRectangle.Height it runs fine.

Example :

Dim InitWidth As Integer = 42
Dim InitHeight As Integer = 42
Dim CImg As New Bitmap (PImg, InitWidth, InitHeight)
' OR:
Dim CImg As New Bitmap (PImg, 42, 42)
' Then runs very well, without errors. Why ??

我已经使用MsgBox测试了e.ClipRectangle.Width:

I have tested e.ClipRectangle.Width with MsgBox:

MsgBox (e.ClipRectangle.Width.Tostring)
               'And MsgBox shows a correct value: 42

我知道我可以通过其他方式执行此操作，但是我想知道为什么会发生这种情况?
其他方法之一是使用控件的 Me.Width 和 Me.Height 属性，但是当我只想使用控件的一部分来绘画时会怎样呢?


使用有效的Me.Width和Me.Height属性的示例.

I know I can do this in other ways, but I want to know why is that happening ?
One of the other ways is to use Me.Width and Me.Height properties of control, but what when i want to use only part of control to draw on it ??


Example using Me.Width and Me.Height properties that works.

Dim CImg As New Bitmap (PImg, Me.Width - 2, Me.Height - 2)

这是整个班级

This is the whole Class

Public Class BtnEx
    Inherits Control
    Private PImg As Image = Nothing
    Public Property Image() As Image
        Get
            Return PImg
        End Get
        Set(ByVal Value As Image)
            PImg = Value
            Me.Refresh()
        End Set
    End Property
    Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
        MyBase.OnPaint(e)
        If PImg Is Nothing = False Then
            Dim CRect As New Rectangle(1, 1, e.ClipRectangle.Width - 2, e.ClipRectangle.Height - 2)
			' MsgBox("InitW : InitH = " + e.ClipRectangle.Width.ToString + " : " + e.ClipRectangle.Heigh.ToString)
            Dim IMGA As New Drawing.Imaging.ImageAttributes
			' ERROR : Parameter is not valid >
            Dim CImg As New Bitmap(PImg, e.ClipRectangle.Width - 2, e.CLipRectangle.Height - 2)
            ' I need to change size of the image (PImg) because user can choose an image that is bigger than by control.
            If Me.Enabled = True Then
                Select Case MS
                    Case EMouseState.MouseHover
                        ' HighLight The Image
                        IMGA.SetGamma(0.57#)
                        e.Graphics.DrawImage(CImg, CRect, 0, 0, CRect.Width, CRect.Height, GraphicsUnit.Pixel, IMGA)
                    Case EMouseState.MouseDown
                        ' Make Image darker
                        IMGA.SetGamma(1.77#)
                        e.Graphics.DrawImage(CImg, CRect, 0, 0, CRect.Width, CRect.Height, GraphicsUnit.Pixel, IMGA)
                    Case EMouseState.MouseUp
                        If InB = True Then ' If mouse is on it.
                            IMGA.SetGamma(0.57#)
                            e.Graphics.DrawImage(CImg, CRect, 0, 0, CRect.Width, CRect.Height, GraphicsUnit.Pixel, IMGA)
                        Else
                            e.Graphics.DrawImage(CImg, CRect)
                        End If
                    Case EMouseState.MouseLeave
                        e.Graphics.DrawImage(CImg, CRect)
                End Select
                Else
                    ' Method used by MicroSoft to paint controls disabled.
                    ControlPaint.DrawImageDisabled(e.Graphics, CImg, 1, 1, Color.Transparent)
            End If
        End If
    End Sub
    Protected Overrides Sub InitLayout()
        MyBase.InitLayout()
	Me.Refresh
    End Sub
    'Used to Refresh Control.
    Private Sub II()
        Me.Refresh()
    End Sub
    Dim InB As Boolean

    Private Enum EMouseState
        MouseUp = 0
        MouseHover = 1
        MouseDown = 2
        MouseLeave = 3
    End Enum
    Dim MS As EMouseState
    Protected Overrides Sub OnMouseEnter(ByVal e As System.EventArgs)
        InB = True
		MyBase.OnMouseEnter(e)
        MS = EMouseState.MouseHover
        II()
    End Sub
    Protected Overrides Sub OnMouseLeave(ByVal e As System.EventArgs)
        MyBase.OnMouseLeave(e)
        InB = False
        MS = EMouseState.MouseLeave
        II()
    End Sub
    Protected Overrides Sub OnMouseDown(ByVal e As System.Windows.Forms.MouseEventArgs)
        MyBase.OnMouseDown(e)
        If e.Button = Windows.Forms.MouseButtons.Left = True Then
            MS = EMouseState.MouseDown
            II()
        End If
    End Sub
    Protected Overrides Sub OnEnabledChanged(ByVal e As System.EventArgs)
        MyBase.OnEnabledChanged(e)
        Me.Refresh()
    End Sub
    Protected Overrides Sub OnMouseUp(ByVal e As System.Windows.Forms.MouseEventArgs)
        MyBase.OnMouseUp(e)
        MS = EMouseState.MouseUp
        II()
    End Sub
    Public Sub New()
        Me.SetStyle(ControlStyles.AllPaintingInWmPaint Or ControlStyles.OptimizedDoubleBuffer Or ControlStyles.ResizeRedraw Or ControlStyles.Selectable Or ControlStyles.SupportsTransparentBackColor Or ControlStyles.UserPaint Or ControlStyles.StandardClick, True)
        Me.DoubleBuffered = True
        MS = EMouseState.MouseLeave
        Me.Refresh()
    End Sub
End Class

最后，对于大问题深表歉意，并在此先感谢.

   

And on the end, sorry for big question, and Thanks in Advance.

  

推荐答案

请对调用的所有三个参数进行完整检查:image(应该是有效的，不能为null )，匹配正宽度和高度.由于涉及设计模式，因此在调试器中很难做到这一点.要调查这种情况，可以使用类System.Diagnostics.EventLog，请参见 http://msdn .microsoft.com/en-us/library/system.diagnostics.eventlog.aspx [
现在，可能的分辨率.设计时可能是一场灾难，很难调试-不要过度使用它.检查属性System.ComponentModel.Component.DesignMode的值，如果在DesignMode为true时执行了控制方法，请避免进行任何详尽的处理或有问题的处理.您的设计模式应仅允许使用正确的边界正确渲染控件，并允许使用PropertyGrid编辑属性.应避免所有仅在应用程序执行模式(而非设计模式)中有用的过多事件处理.

请参阅 http://msdn.microsoft.com/en-us/library/system .componentmodel.component.designmode.aspx [ ^ ].

-SA

Please do some sanity check of all of three parameters of the call: image (should be valid, not null), matching positive width and height. This is hard to do under debugger as Design mode is involved. To investigate the situation, you can use the class System.Diagnostics.EventLog, see http://msdn.microsoft.com/en-us/library/system.diagnostics.eventlog.aspx[^].

You will get all the log information in the system log where you can examine it using the "Event Log" viewer, using "Eventvwr.msc".

Now, the possible resolution. Design-time can be a disaster, very hard to debug — don''t overuse it. Check up the value of the property System.ComponentModel.Component.DesignMode and avoid any extensive or questionable processing if your control methods are executed when the DesignMode is true. Your design mode should only allow to render your control correctly with correct bounds and allow for editing of the properties using the PropertyGrid. All excessive event processing useful only in application execution mode (not design mode) should be avoided.

See http://msdn.microsoft.com/en-us/library/system.componentmodel.component.designmode.aspx[^].

—SA

@ SAKryukov -感谢您的快速回复.我很感激.

@SAKryukov - Thank you for the quick reply. I appreciate it.

报价:

请对调用的所有三个参数进行完整检查:图像(应该是有效的，不能为null)，匹配正宽度和高度.

Please do some sanity check of all of three parameters of the call: image (should be valid, not null), matching positive width and height.

我已经检查了代码中的图片:

I have checked the image in the code:

If PImg Is Nothing = False

而且我还用MsgBox检查了高度和宽度:

And I have also checked Height and Width with MsgBox:

MsgBox ("Height is : " + e.ClipRectangle.Height.ToString)
' MsgBox returns the correct value : 42 in this case

但是，在您的帮助下，我当然找到了解决方案.
你给我一个主意.

我将此代码放在OnPaint Sub中.它检查程序是否处于设计模式.

But I have found a solution, of course, with your help.
You gave me an idea.

I put this code in the OnPaint Sub. It checks if the program is in Design Mode or not.

' Using Control.DesignMode
If Me.DesignMode = True Then
' Do some stuff like : Draw image without using e.ClipRectangle, or something else
Else ' Running, draw images correctly
Dim CImg As New Bitmap (PImg, e.ClipRectangle.Width - 2, e.ClipRectangle.Height - 2)
' ... ... ...
End If

而且它可以正常工作.
您使用Control.DesingMode的想法很棒.
这使我可以从PropertyGrid
编辑属性
我为你的ansewr投了5票.非常感谢.

And it works without any error.
Your idea to using a Control.DesingMode is great.
This allow me to edit properies from the PropertyGrid

I voted 5 for your ansewr. Thanks a lot.

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