CODEWITHSUNDEEP
c#visual-studio-2013
user2781018
user2781018

Reputation:

Add Attributes to Form Class

I want to change the location of the messagebox in my c# application for visual studio 2013. I found this article:

http://www.codeproject.com/Tips/472294/Position-a-Windows-Forms-MessageBox-in-Csharp

It says "In your Form class, add these DllImport attributes."

What does this actually need me to do? I went to my System.Windows.Forms reference. If that's where I need to be do add this code, I have no idea where it needs to be added within there as there is a lot of stuff going on that I have no idea about.

Upvotes: 0

Views: 552

Answers (2)

Gun
Gun

Reputation: 1411

Import the below name spaces 

using System.Runtime.InteropServices;
using System.Threading;

Write the below code in class level (If you want information regrading these methods please refer pinvoke

    [DllImport("user32.dll")]
    static extern IntPtr FindWindow(IntPtr classname, string title);

    [DllImport("user32.dll")]
    static extern void MoveWindow(IntPtr hwnd, int X, int Y,int nWidth, int nHeight, bool rePaint);

    [DllImport("user32.dll")]
    static extern bool GetWindowRect(IntPtr hwnd, out Rectangle rect);

Write the FindAndMoveMsgBox method and call wherever you want

Here I called the method in Form1 constructor and below is the final code

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Threading;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {

        [DllImport("user32.dll")]
        static extern IntPtr FindWindow(IntPtr classname, string title);

        [DllImport("user32.dll")]
        static extern void MoveWindow(IntPtr hwnd, int X, int Y,int nWidth, int nHeight, bool rePaint);

        [DllImport("user32.dll")]
        static extern bool GetWindowRect(IntPtr hwnd, out Rectangle rect);


        public Form1()
        {
            InitializeComponent();
            FindAndMoveMsgBox(0, 0, true, "Title");
            MessageBox.Show("Message", "Title");
        }

        void FindAndMoveMsgBox(int x, int y, bool repaint, string title)
        {
            Thread thr = new Thread(() => // create a new thread
            {
                IntPtr msgBox = IntPtr.Zero;
                // while there's no MessageBox, FindWindow returns IntPtr.Zero
                while ((msgBox = FindWindow(IntPtr.Zero, title)) == IntPtr.Zero) ;
                // after the while loop, msgBox is the handle of your MessageBox
                Rectangle r = new Rectangle();
                GetWindowRect(msgBox, out r); // Gets the rectangle of the message box
                MoveWindow(msgBox /* handle of the message box */, x, y,
                   r.Width - r.X /* width of originally message box */,
                   r.Height - r.Y /* height of originally message box */,
                   repaint /* if true, the message box repaints */);
            });
            thr.Start(); // starts the thread
        }
    }
}

Upvotes: 4

HeXanon
HeXanon

Reputation: 514

(See answer above - posted while I was typing the code up :) ) What 'DLLImport' does is allows you to call functions in unmanaged code from managed code. This is called Platform Invocation Services (or PInvoke)

Before making use of PInvoke services, I would urge you to familiarise yourself with PInvoke and how it works. PInvoke is great and I make use of it a lot for OS manipulation such as the link you posted.

Dated, but still a good PInvoke tutoriual: http://msdn.microsoft.com/en-us/library/aa288468(v=vs.71).aspx

To answer the question: Add those lines of code at the top of the Form.cs file (In the class reference)

public partial class MyForm : Form
{
    [DllImport("user32.dll")]
    static extern IntPtr FindWindow(IntPtr classname, string title); // extern method: FindWindow

    [DllImport("user32.dll")]
    static extern void MoveWindow(IntPtr hwnd, int X, int Y,
        int nWidth, int nHeight, bool rePaint); // extern method: MoveWindow

    [DllImport("user32.dll")]
    static extern bool GetWindowRect
        (IntPtr hwnd, out Rectangle rect); // extern method: GetWindowRect
//ETC

Upvotes: 0

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