有一种方法可以使MessageBox居中而不进行子类化或挂钩？
我正在寻找VB.NET代码。
答案 0 :(得分：8)
VB.NET的解决方案：
此代码摘自@Hans Passant asnwer：Winforms-How can I make MessageBox appear centered on MainForm?
Centered_MessageBox.vb
Imports System.Text
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Runtime.InteropServices
Class Centered_MessageBox
Implements IDisposable
Private mTries As Integer = 0
Private mOwner As Form
Public Sub New(owner As Form)
mOwner = owner
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
End If
' Got it
Dim frmRect As New Rectangle(mOwner.Location, mOwner.Size)
Dim dlgRect As RECT
GetWindowRect(hWnd, dlgRect)
MoveWindow(hWnd, frmRect.Left + (frmRect.Width - dlgRect.Right + dlgRect.Left) \ 2, frmRect.Top + (frmRect.Height - dlgRect.Bottom + dlgRect.Top) \ 2, dlgRect.Right - dlgRect.Left, dlgRect.Bottom - dlgRect.Top, True)
Return False
End Function
Public Sub Dispose() Implements IDisposable.Dispose
mTries = -1
End Sub
' P/Invoke declarations
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 GetWindowRect(hWnd As IntPtr, ByRef rc As RECT) As Boolean
End Function
<DllImport("user32.dll")> _
Private 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
Private Structure RECT
Public Left As Integer
Public Top As Integer
Public Right As Integer
Public Bottom As Integer
End Structure
End Class
用法：
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Using New Centered_MessageBox(Me)
MessageBox.Show("Test Text", "Test Title", MessageBoxButtons.OK)
End Using
End Sub
答案 1 :(得分：1)
可悲的是，没有办法将MessageBox置于父母的中心。默认情况下，它以屏幕为中心，无法更改。
答案 2 :(得分：1)
创建自己的-轻松创建表单（摆脱属性设置为false的控制箱） 放置文本框（称为TextBox_Prompt）并将其设置为多行属性 在文本框下方添加3个按钮（宽度/高度足以舒适地按住“ CANCEL”） 在表单中添加以下代码（我使用|字符表示换行符）：
Public Class frmMsgBox
Private mName As String = "Message Box" ' default name for form
Private mLocation As Point = New Point(400, 400) ' default location in case user does set
Private mStyle As MsgBoxStyle
Private mPrompt As String
Private mResult As MsgBoxResult
Private b1Result As MsgBoxResult
Private b2Result As MsgBoxResult
Private b3Result As MsgBoxResult
Public WriteOnly Property Style As MsgBoxStyle
Set(value As MsgBoxStyle)
mStyle = value
End Set
End Property
Public WriteOnly Property Prompt As String
Set(value As String)
mPrompt = value
End Set
End Property
Public ReadOnly Property Result As MsgBoxResult
Get
Return mResult
End Get
End Property
Public WriteOnly Property pLocation As Point
Set(value As Point)
mLocation = value
End Set
End Property
Public WriteOnly Property sName As String
Set(value As String)
mName = value
End Set
End Property
Private Sub frmMsgBox_Load(sender As Object, e As EventArgs) Handles Me.Load
Dim strPrompt() As String = mPrompt.Split("|") ' use | for splitting lines
Dim sWidth As Integer = 0
Dim sHeight As String = ""
Me.Text = mName
For Each sLine As String In strPrompt ' get maximum width and height necessary for Prompt TextBox
sWidth = Math.Max(sWidth, TextRenderer.MeasureText(sLine, TextBox_Prompt.Font).Width)
sHeight += "@" + vbCrLf ' TextRenderer.MeasureText("@", TextBox_Prompt.Font).Height
TextBox_Prompt.Text += sLine + vbCrLf
Next
TextBox_Prompt.Width = Math.Min(800, sWidth + 5) ' set max width arbitrarily at 800
TextBox_Prompt.Height = Math.Min(600, TextRenderer.MeasureText(sHeight, TextBox_Prompt.Font).Height) ' set max height to 600 pixels
Me.Width = Math.Max(Me.Width, TextBox_Prompt.Width + Me.Width - Me.ClientRectangle.Width + 20)
TextBox_Prompt.Left = Math.Max(10, (Me.ClientRectangle.Width - TextBox_Prompt.Width) \ 2)
Button1.Top = TextBox_Prompt.Top + TextBox_Prompt.Height + 20
Button2.Top = Button1.Top : Button3.Top = Button1.Top
Me.Height = Me.Height - Me.ClientRectangle.Height + 2 * TextBox_Prompt.Top + TextBox_Prompt.Height + Button1.Height + 20
Dim Space2 As Integer = (Me.ClientRectangle.Width - 2 * Button1.Width) / 3
Dim Space3 As Integer = (Me.ClientRectangle.Width - 3 * Button1.Width) / 4
Select Case mStyle
Case MsgBoxStyle.AbortRetryIgnore
Button1.Text = "Abort" : Button2.Text = "Retry" : Button3.Text = "Ignore"
Button1.Left = Space3
Button2.Left = 2 * Space3 + Button1.Width
Button3.Left = 3 * Space3 + 2 * Button1.Width
b1Result = MsgBoxResult.Abort : b2Result = MsgBoxResult.Retry : b3Result = MsgBoxResult.Ignore
Case MsgBoxStyle.YesNoCancel
Button1.Text = "Yes" : Button2.Text = "No" : Button3.Text = "Cancel"
Button1.Left = Space3
Button2.Left = 2 * Space3 + Button1.Width
Button3.Left = 3 * Space3 + 2 * Button1.Width
b1Result = MsgBoxResult.Yes : b2Result = MsgBoxResult.No : b3Result = MsgBoxResult.Cancel
Case MsgBoxStyle.YesNo
Button1.Text = "Yes" : Button2.Text = "No" : Button3.Visible = False
Button1.Left = Space2
Button2.Left = 2 * Space2 + Button1.Width
b1Result = MsgBoxResult.Yes : b2Result = MsgBoxResult.No
Case MsgBoxStyle.OkCancel
Button1.Text = "Ok" : Button2.Text = "Cancel" : Button3.Visible = False
Button1.Left = Space2
Button2.Left = 2 * Space2 + Button1.Width
b1Result = MsgBoxResult.Ok : b2Result = MsgBoxResult.Cancel
Case MsgBoxStyle.RetryCancel
Button1.Text = "Retry" : Button2.Text = "Cancel" : Button3.Visible = False
Button1.Left = Space2
Button2.Left = 2 * Space2 + Button1.Width
b1Result = MsgBoxResult.Retry : b2Result = MsgBoxResult.Cancel
Case MsgBoxStyle.OkOnly
Button1.Visible = False : Button2.Text = "Ok" : Button3.Visible = False
Button1.Left -= Space2 : Button2.Width += 2 * Space2
b2Result = MsgBoxResult.Ok
End Select
Me.Location = New Point(mLocation.X - Me.Width \ 2, mLocation.Y - Me.Height \ 2)
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
mResult = b1Result
Me.Close()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
mResult = b2Result
Me.Close()
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
mResult = b3Result
Me.Close()
End Sub
End Class
要使用您的程序，您可以执行以下操作
Dim ans as MsgBoxResult
Using f As New frmMsgBox With {
.sName = "form tile goes here ",
.Style = MsgBoxStyle.YesNoCancel, ' or whatever style
.Prompt = "Your prompt|2nd line||4th line",
.pLocation = New Point(Me.Left + Me.Width \ 2, Me.Top + Me.Height \ 2)
} ' this location will center MsgBox on form
f.ShowDialog()
ans = f.Result
End Using
If ans = MsgBoxResult.Yes Then
'do whatever
ElseIf ans = MsgBoxResult.No then
'do not whatever
Else ' was cancel
' do cancel
End If
我一直在使用此表格 您还可以将图片属性/框以及其他内容添加到表单中。 乔治
答案 3 :(得分：1)
这是我自己的消息框使用C#winform，除了在中心实现父窗体外，还可以自定义按钮文字和图标。您可以自行将其转换为 VB 代码。
using System;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
namespace BluePointLilac.Methods
{
/// <summary>在窗体居中显示的MessageBox</summary>
public class MessageBoxEx
{
public static DialogResult Show(string text, string caption = null,
MessageBoxButtons buttons = MessageBoxButtons.OK,
MessageBoxIcon boxIcon = MessageBoxIcon.None)
{
using(MessageBoxForm frm = new MessageBoxForm(text, caption, buttons, boxIcon))
{
return frm.ShowDialog();
}
}
public static string Show(string text, string caption,
string[] buttonTexts, Image boxImaage, bool cancelBox = false)
{
using(MessageBoxForm frm = new MessageBoxForm(text, caption, buttonTexts, boxImaage, cancelBox))
{
frm.ShowDialog();
return frm.Tag?.ToString();
}
}
sealed class MessageBoxForm : Form
{
private MessageBoxForm(string text, string caption)
{
lblText.Text = text;
this.Text = caption;
this.Font = SystemFonts.MessageBoxFont;
this.ShowIcon = this.ShowInTaskbar = false;
this.MaximizeBox = this.MinimizeBox = false;
this.FormBorderStyle = FormBorderStyle.FixedSingle;
this.StartPosition = FormStartPosition.CenterParent;
}
public MessageBoxForm(string text, string caption,
string[] buttonTexts, Image boxImage, bool cancelBox) : this(text, caption)
{
this.CancelBox = cancelBox;
this.InitializeComponents(buttonTexts, boxImage);
foreach(Button button in flpButtons.Controls)
{
button.Click += (sender, e) =>
{
this.Tag = button.Text;
this.Close();
};
}
}
public MessageBoxForm(string text, string caption,
MessageBoxButtons buttons, MessageBoxIcon boxIcon) : this(text, caption)
{
string[] buttonTexts = null;
Image boxImage = null;
switch(buttons)
{
case MessageBoxButtons.OK:
buttonTexts = new[] { "OK" }; break;
case MessageBoxButtons.OKCancel:
buttonTexts = new[] { "Cancel", "OK" }; break;
case MessageBoxButtons.AbortRetryIgnore:
buttonTexts = new[] { "&Ignore", "&Retry", "&Abort" }; break;
case MessageBoxButtons.YesNoCancel:
buttonTexts = new[] { "Cancel", "&No", "&Yes" }; break;
case MessageBoxButtons.YesNo:
buttonTexts = new[] { "&No", "&Yes" }; break;
case MessageBoxButtons.RetryCancel:
buttonTexts = new[] { "Cancel", "&Retry" }; break;
}
switch(boxIcon)
{
case MessageBoxIcon.Question:
boxImage = SystemIcons.Question.ToBitmap(); break;
case MessageBoxIcon.Error:
boxImage = SystemIcons.Error.ToBitmap(); break;
case MessageBoxIcon.Warning:
boxImage = SystemIcons.Warning.ToBitmap(); break;
case MessageBoxIcon.Information:
boxImage = SystemIcons.Information.ToBitmap(); break;
}
this.CancelBox = !buttonTexts.Contains("Cancel");
this.InitializeComponents(buttonTexts, boxImage);
foreach(Button button in flpButtons.Controls)
{
button.Click += (sender, e) =>
{
switch(button.Text)
{
case "OK":
this.DialogResult = DialogResult.OK; break;
case "Cancel":
this.DialogResult = DialogResult.Cancel; break;
case "&Yes":
this.DialogResult = DialogResult.Yes; break;
case "&No":
this.DialogResult = DialogResult.No; break;
case "&Abort":
this.DialogResult = DialogResult.Abort; break;
case "&Retry":
this.DialogResult = DialogResult.Retry; break;
case "&Ignore":
this.DialogResult = DialogResult.Ignore; break;
}
};
}
}
private void InitializeComponents(string[] buttonTexts, Image boxImage)
{
int w1 = 0;
Size buttonSize = new Size(75, 27);
for(int i = 0; i < buttonTexts.Length; i++)
{
Button button = new Button
{
Margin = new Padding(0, 12, 12, 12),
Parent = flpButtons,
AutoSize = true,
Text = buttonTexts[i],
};
button.Width = Math.Max(buttonSize.Width, button.Width);
button.Height = Math.Max(buttonSize.Height, button.Height);
buttonSize = button.Size;
w1 += button.Width + button.Margin.Horizontal;
}
picIcon.Image = boxImage;
if(boxImage == null)
{
picIcon.Visible = false;
lblText.Left = 35;
}
pnlInfo.Controls.AddRange(new Control[] { picIcon, lblText });
this.Controls.AddRange(new Control[] { pnlInfo, flpButtons });
pnlInfo.Height = lblText.Height + lblText.Top * 2;
int w2 = lblText.Right + picIcon.Left;
int w = Math.Max(w1, w2);
int h = pnlInfo.Height + flpButtons.Height;
this.ClientSize = new Size(w, h);
}
readonly FlowLayoutPanel flpButtons = new FlowLayoutPanel
{
Padding = new Padding(0, 0, 12, 0),
FlowDirection = FlowDirection.RightToLeft,
BackColor = default,
Dock = DockStyle.Bottom,
Height = 50
};
readonly Panel pnlInfo = new Panel
{
BackColor = Color.White,
Dock = DockStyle.Top,
};
readonly PictureBox picIcon = new PictureBox
{
SizeMode = PictureBoxSizeMode.AutoSize,
Location = new Point(30, 30)
};
readonly Label lblText = new Label
{
Location = new Point(67, 32),
AutoSize = true,
};
readonly bool CancelBox = false;
protected override CreateParams CreateParams
{
get
{
const int CP_NOCLOSE_BUTTON = 0x200;
CreateParams cp = base.CreateParams;
if(CancelBox) cp.ClassStyle |= CP_NOCLOSE_BUTTON; //禁用关闭按钮
return cp;
}
}
protected override bool ProcessDialogKey(Keys keyData)
{
if(ModifierKeys == Keys.None)
{
if(!CancelBox && keyData == Keys.Escape)
{
this.DialogResult = DialogResult.Cancel; //ESC键关闭窗体并返回“取消”
return true;
}
}
return base.ProcessDialogKey(keyData);
}
protected override void OnLoad(EventArgs e)
{
this.Owner = Form.ActiveForm;
if(this.Owner == null) this.StartPosition = FormStartPosition.CenterScreen;
base.OnLoad(e);
}
}
}
}