Pfthb

I am creating an application in which I can move the Labels that are on a PictureBox.

The problem is that I want these to only Labels move inside the PictureBox.

Here is my code:

protected void lbl_MouseMove(object sender, MouseEventArgs e)

 Label lbl = sender as Label;

 try
 
 if (lbl != null && e.Button == MouseButtons.Left)
 
 if (m_lblLocation != new Point(0, 0))
 
 Point newLocation = lbl.Location;
 newLocation.X = newLocation.X + e.X - m_lblLocation.X;
 newLocation.Y = newLocation.Y + e.Y - m_lblLocation.Y;
 lbl.Location = newLocation;
 this.Refresh();
 
 
 
 catch(Exception ex) 


protected void lbl_MouseUp(object sender, MouseEventArgs e)

 Label lbl = sender as Label;

 try
 
 if (lbl != null && e.Button == MouseButtons.Left)
 
 m_lblLocation = Point.Empty;
 
 
 catch(Exception ex) 


protected void lbl_MouseDown(object sender, MouseEventArgs e)

 Label lbl = sender as Label;

 try
 
 if (lbl != null && e.Button == MouseButtons.Left)
 
 m_lblLocation = e.Location;
 
 
 catch(Exception ex) 

In above code I have created some mouse events for the Labels.

The PictureBox control is not a container, you can't directly put another control inside it, as you would do with a Panel, a GroupBox or other controls that implement IContainerControl.

You could parent the Label (in this case), setting the Label Parent to a PictureBox handle. The Label.Bounds will then reflect the parent Bounds.

However it's not necessary: you can just calculate the position of the Label in relation to the control that contains both (Label(s) and PictureBox):

You can restrict the movements of other Label controls subscribing to the MovableLabel_MouseDown/MouseUp/MouseMove events.

An example:

bool ThisLabelCanMove;
Point LabelMousePosition = Point.Empty;

private void MovableLabel_MouseDown(object sender, MouseEventArgs e)

 if (e.Button == MouseButtons.Left)
 
 LabelMousePosition = e.Location;
 ThisLabelCanMove = true;
 


private void MovableLabel_MouseUp(object sender, MouseEventArgs e)

 ThisLabelCanMove = false;


private void MovableLabel_MouseMove(object sender, MouseEventArgs e)

 if (ThisLabelCanMove)
 
 Label label = sender as Label;

 Point LabelNewLocation = new Point(label.Left + (e.Location.X - LabelMousePosition.X),
 label.Top + (e.Location.Y - LabelMousePosition.Y));
 LabelNewLocation.X = (LabelNewLocation.X < pictureBox1.Left) ? pictureBox1.Left : LabelNewLocation.X;
 LabelNewLocation.Y = (LabelNewLocation.Y < pictureBox1.Top) ? pictureBox1.Top : LabelNewLocation.Y;
 LabelNewLocation.X = (LabelNewLocation.X + label.Width > pictureBox1.Right) ? label.Left : LabelNewLocation.X;
 LabelNewLocation.Y = (LabelNewLocation.Y + label.Height > pictureBox1.Bottom) ? label.Top : LabelNewLocation.Y;
 label.Location = LabelNewLocation;
 

you need to track two things:
1. is the mouse press or not - bool IsMouseDown = false;
2. the start location of the label- Point StartPoint;

// mouse is not down
private void label1_MouseUp(object sender, MouseEventArgs e)

 IsMouseDown = false;



 //mouse is down and set the starting postion
 private void label1_MouseDown(object sender, MouseEventArgs e)
 
 //if left mouse button was pressed
 if (e.Button == System.Windows.Forms.MouseButtons.Left)
 
 IsMouseDown = true;
 label1.BringToFront();
 StartPoint = e.Location;
 
 


 //check the label is withing the borders of the picture box
 private void label1_MouseMove(object sender, MouseEventArgs e)
 
 if (IsMouseDown)
 
 int left = e.X + label1.Left - StartPoint.X;
 int right = e.X + label1.Right - StartPoint.X;
 int top = e.Y + label1.Top - StartPoint.Y;
 int bottom = e.Y + label1.Bottom - StartPoint.Y;
 if (left > pictureBox1.Left && top > pictureBox1.Top && pictureBox1.Bottom >= bottom && pictureBox1.Right >= right)
 
 label1.Left = left;
 label1.Top = top;