Free Drawing trick in C#

While studying C# ,one of my friends had an idea to write  a C# program that enables user to make a free drawing shapes using C# graphics

so i have open my compiler ,have a moment of silence and started to code

My idea was to get the point when the user first clicked on the form,then while he is holding down the mouse button & moving i have to get the distance between the first position the mouse was clicked & the current position (width& height argument).

Lest’s start coding,

to get the first moue click position here we got two data members to store the first position,also w have a boolean data member to know if the mouse is still down or not

bool paintThis = false;  
int x;  
int y;

then in the mouse down event we get these two guys x&y of the first position and set the paintThis to true

private void Form1_MouseDown(object sender, MouseEventArgs e)  
	paintThis = true;  
	x = e.X;  
	y = e.Y;

then in the mouse up event we set the paintThis to false

private void Form1_MouseUp(object sender, MouseEventArgs e)  
	paintThis = false;  

here in the mouse move event all the work will be done,we’ll calculate the width & the height of the rectangle we want to draw and start drawing when the mouse is down(actually when paintThis=true) at the first position the mouse was down (x & y)

private void Form1_MouseMove(object sender, MouseEventArgs e)  
	if (paintThis)  
		Graphics gf = this.CreateGraphics();  
		gf.DrawRectangle(new Pen(Color.Black), x,y, e.X-x, e.Y-y);  

here the source files

hope you have enjoyed