How to draw multiple rectangles using c#
- by Nivas
I have drawn and saved the Rectangle on the image i loaded in the picture box. How i like to draw multiple rectangles for that i tried array in the rectangle but it gives error ("Object reference not set to an instance of an object." (Null reference Exception was unhandled).
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
if (mybitmap == null)
{
mybitmap = new Bitmap(sz.Width, sz.Height);
}
rect[count] = new Rectangle(e.X, e.Y, 0, 0);
this.Invalidate();
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (stayToolStripMenuItem.Checked == true)
{
switch (e.Button)
{
case MouseButtons.Left:
{
rect[count] = new Rectangle(rect[count].Left, rect[count].Top, e.X - rect[count].Left, e.Y - rect[count].Top);
pictureBox1.Invalidate();
count++:
break;
}
}
}
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
if (stayToolStripMenuItem.Checked == true)
{
button1.Visible = true;
button2.Visible = true;
if (mybitmap == null)
{
return;
}
using (g = Graphics.FromImage(mybitmap))
{
using (Pen pen = new Pen(Color.Red, 2))
{
//g.Clear(Color.Transparent);
e.Graphics.DrawRectangle(pen, rect);
label1.Top = rect[count].Top; label1[count].Left = rect[count].Left; label1.Width = rect[count].Width;
label1.Height = rect[count].Height;
if (label1.TextAlign == ContentAlignment.TopLeft)
{
e.Graphics.DrawString(label1.Text, label1.Font, new SolidBrush(label1.ForeColor), rect);
g.DrawString(label1.Text, label1.Font, new SolidBrush(label1.ForeColor), rect);
g.DrawRectangle(pen, rect[count]);
}
}
}
}
}
How can i do this.....
