I have a PictureBox called pic, placed inside another PictureBox called picTrack.
My goal is to be able to let the user, at run time, change the position of pic by draging it.
This is what I have so far:
int x_offset = 0; // any better to do this without having a global variable?
int y_offset = 0;
void pic_MouseDown(object sender, MouseEventArgs e)
{
PictureBox me = (PictureBox)sender;
x_offset = me.Left - e.X;
y_offset = me.Top - e.Y;
}
void pic_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
PictureBox me = (PictureBox)sender;
me.Left = e.X + x_offset;
me.Top = e.Y + y_offset;
picTrack.Invalidate();
}
}
This code only works at a very basic level. I have 2 problems with it:
1.) picTrack is not updated if the user does not let go of the mouse button. Ghost images of pic can be seen while pic is getting moved around (it's like pic is having a tail).
2.) pic is "giggling" (i.e. rapidly shaking left and right, up and down, around its location).
How should I solve these 2 problems and create a more smooth drag & drop? Thanks.
Here this actually works, I've written quite a few dragging things before.. it may not be perfect but this should give you something to work with.
Point dragPoint = Point.Empty;
bool dragging = false;
private void pic_MouseDown(object sender, MouseEventArgs e)
{
dragging = true;
dragPoint = new Point(e.X, e.Y);
}
private void pic_MouseMove(object sender, MouseEventArgs e)
{
if (dragging)
pic.Location = new Point(pic.Location.X + e.X - dragPoint.X, pic.Location.Y + e.Y - dragPoint.Y);
}
private void pic_MouseUp(object sender, MouseEventArgs e)
{
dragging = false;
}
See, if you were dragging a local picture that you were just rendering yourself, this wouldn't be right.. but since you are moving a control after you move it, the new move coordinates are relative to the control. Therefore, you do not need to update dragPoint to the last position on move. If you were just moving a shape/image you were rendering OnPaint, you'd have to do update the drag point each movement.
There's one improvement you could make, if desired, which is to only start dragging if the user moves the cursor a certain distance D. For example, something like this:
Point dragPoint = Point.Empty;
bool dragging = false;
bool mouseDown = false;
private void pic_MouseDown(object sender, MouseEventArgs e)
{
mouseDown = true;
dragPoint = new Point(e.X, e.Y);
}
private void pic_MouseMove(object sender, MouseEventArgs e)
{
int deltaX = e.X - dragPoint.X;
int deltaY = e.Y - dragPoint.Y;
if (!dragging && mouseDown && deltaX * deltaX + deltaY * deltaY > 100)
dragging = true;
if (dragging)
pic.Location = new Point(pic.Location.X + deltaX, pic.Location.Y + deltaY);
}
private void pic_MouseUp(object sender, MouseEventArgs e)
{
dragging = false;
mouseDown = false;
}
Which checks if the user has moved the mouse 10 pixels (sqrt of 100).
If you don't want a global, you could try implementing your own behavior system and creating a reusable piece of code that you can attach to things you want to move. Something like this:
public class Behavior<T> where T : class
{
public T AssociatedObject
{
get;
private set;
}
public Behavior(T associatedObject)
{
this.AssociatedObject = associatedObject;
}
public virtual void Attach() { }
public virtual void Detach() { }
}
public class DragBehavior : Behavior<Control>
{
Point dragPoint = Point.Empty;
bool dragging = false;
bool mouseDown = false;
public DragBehavior(Control c) : base(c)
{
}
public override void Attach()
{
AssociatedObject.MouseDown += new MouseEventHandler(control_MouseDown);
AssociatedObject.MouseMove += new MouseEventHandler(control_MouseMove);
AssociatedObject.MouseUp += new MouseEventHandler(control_MouseUp);
}
private void control_MouseUp(object sender, MouseEventArgs e)
{
dragging = false;
mouseDown = false;
}
private void control_MouseMove(object sender, MouseEventArgs e)
{
int deltaX = e.X - dragPoint.X;
int deltaY = e.Y - dragPoint.Y;
if (mouseDown && deltaX * deltaX + deltaY * deltaY > 100)
dragging = true;
if (dragging)
AssociatedObject.Location = new Point(AssociatedObject.Location.X + deltaX, AssociatedObject.Location.Y + deltaY);
}
private void control_MouseDown(object sender, MouseEventArgs e)
{
mouseDown = true;
dragPoint = new Point(e.X, e.Y);
}
public override void Detach()
{
AssociatedObject.MouseDown -= new MouseEventHandler(control_MouseDown);
AssociatedObject.MouseMove -= new MouseEventHandler(control_MouseMove);
AssociatedObject.MouseUp -= new MouseEventHandler(control_MouseUp);
}
}
public partial class Form1 : Form
{
DragBehavior dragger;
public Form1()
{
InitializeComponent();
DoubleBuffered = true;
dragger = new DragBehavior(pic);
dragger.Attach();
}
}
Maybe that is better than "creating a global variable" (or more like creating a member variable in your form. =)
Try this
int x_offset = 0; // any better to do this without having a global variable?
int y_offset = 0;
private void pic_MouseDown(object sender, MouseEventArgs e)
{
PictureBox me = (PictureBox)sender;
x_offset = e.X;
y_offset = e.Y;
}
private void pic_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
PictureBox me = (PictureBox)sender;
me.Left = e.X + me.Left - x_offset;
me.Top = e.Y + me.Top - y_offset;
}
}
Related
I am attempting to drag Music Notes vertically, up and down a Music Staff. However, rather than a constant drag, I would like the music notes to only be allowed to be dragged onto particular intervals (only specific y-coordinates). For example, in a vertical line, a music note can be dragged on to coordinates (0,0), (0,5) or (0,10).
Below is my relevant code:
private Point MouseDownLocation;
private void Note_MouseDown(object sender, MouseEventArgs e)
{
foreach (MusicNote mn in panel2.Controls.OfType<MusicNote>())
{
if (sender == mn)
{
if (e.Button == MouseButtons.Left)
{
MouseDownLocation = e.Location;
}
}
}
}
private void Note_MouseMove(object sender, MouseEventArgs e)
{
foreach(MusicNote mn in panel2.Controls.OfType<MusicNote>())
{
if (sender == mn)
{
if (e.Button == MouseButtons.Left)
{
mn.Top = e.Y + mn.Top - MouseDownLocation.Y;
}
}
}
}
Any help is appreciated. Thank you!
Basically, you need to check if you drag up or drag down
You should want to check the MouseDown.X and compare it to the MouseUp.X (or Y if you want to check vertical direction as well). It is important to note that (0, 0) is the upper left of your screen. So you need to compare the X position from mouse down event to the mouse up event.
here's an example with one label that moves up and down in steps of 10
private void label1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
if (label1.Location.Y > 0 && label1.Location.Y < panel1.Size.Height) // not the most accurate way, but you get the idea
{
mPointDown = new Point(e.X, e.Y);
}
}
}
private void label1_MouseUp(object sender, MouseEventArgs e)
{
bool movedUp, movedDown;
if (e.Y == mPointDown.Y)
{
movedUp = movedDown = false;
}
else
{
movedUp = e.Y < mPointDown.Y;
movedDown = !movedUp;
}
if (movedDown)
{
label1.Location = new Point(label1.Location.X, label1.Location.Y + 10);
}
else if (movedUp)
{
label1.Location = new Point(label1.Location.X, label1.Location.Y - 10);
}
}
private void label1_MouseMove(object sender, MouseEventArgs e)
{
mouseDownPoint = e.Location;
}
How to move a pictureBox inside a Panel by Mouse.
Visual Studio 2015 C# Winsows Forms Application.
I've made a primitive slider to control the volume of my WindowsMediaPlayer.
A panel as the background and a pictureBox inside as the slider-knopf.
And it works well.
But purely visually it does not work that good.
I'v searched all around, but can't I find an answer to this little funny problem.
Here is my code:
int posY;
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
posY = e.Y; ;
}
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
PictureBox box = sender as PictureBox;
if (e.Button == MouseButtons.Left)
{
box.Top += e.Y - posY;
}
if (box.Top < 0)
{
box.Top = 0;
}
if (box.Top > 100)
{
box.Top = 100;
}
int n = box.Top;
n = n * - 1 + 100;
label1.Text = n.ToString();
}
When I move the pictureBox out of the edge of the little panel, the pictureBox somehow 'shrinks' in the panel.
But when I release the mouse, the pictureBox restore its size.
Slider.gif
Why is that.?
And how can I avoid it.?
Thanks.
I found a solution.
It's not optimal, but it can be used.
I changed the code to:
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
dragging = true;
startPoint = e.Location;
}
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (dragging)
{
Debug.WriteLine("mousemove X: " + e.X + " Y: " + e.Y);
pictureBox1.Location = new Point(0, pictureBox1.Top + e.Location.Y - startPoint.Y);
if (pictureBox1.Location.Y < 0)
{
pictureBox1.Location = new Point(0, 0);
dragging = false;
}
if (pictureBox1.Location.Y > 100)
{
pictureBox1.Location = new Point(0, 100);
dragging = false;
}
this.Refresh();
}
int n = pictureBox1.Location.Y;
n = n * -1 + 100;
label1.Text = n.ToString();
mediaPlayer1.settings.volume = n;
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
dragging = false;
}
gif
I still need to put an 'if' to correct, when the pictureBox1 is pulled out of the panel.
And to avoid flicker, I have had to put a 'dragging = false'.
However, it results in the pictureBox1 is getting frozen to the edge, so I have to release the mouse, and re-click to continue.
But well - it's to live with.
Thanks.
How to receive a path of relocation of a mouse between the 1st clicking and the 2nd?
private void OnMouseDown(object sender, MouseEventArgs e)
{
Log(string.Format("MouseDown \t\t {0}\n", e.Button));
LogMousePosition(string.Format("\n\nx={0:0000}\ny={1:0000}", e.X, e.Y));
if (lastX != -100 && lastY != -100)
{
shortestDistanse = Convert.ToInt64(Math.Sqrt((Math.Pow(e.X - lastX, 2)) + (Math.Pow(e.Y - lastY, 2))));
LogMousePosition(string.Format("\nshortDistanse\t\t {0}\n", shortestDistanse));
}
lastX = e.X;
lastY = e.Y;
}
If you just want the distance between the two points use pythagora.
Example:
private double GetDistance(Point p1, Point p2) {
int x = Math.Abs(p1.X - p2.X);
int y = Math.Abs(p1.Y - p2.Y);
return Math.Sqrt( Math.Pow(x, 2) + Math.Pow(y, 2));
}
You may try something like
// form fields
bool pressed;
List<Point> path;
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
if (!pressed)
{
pressed = true;
path = new List<Point>();
path.Add(e.Location);
}
else
{
pressed = false;
// calculate distance from List
// log distance
}
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (pressed)
{
path.Add(e.Location);
}
}
However, the MouseMove event will be triggered only above the form. If the mouse is outside of it - distance is not taken into account. It also doesn't work when moving over other controls, but we can add to them MouseMove handlers too.
I could make
string pathMList = "C:\\logs/testMList.txt";`
private void HookManager_MouseMove(object sender, MouseEventArgs e)
{
labelMousePosition.Text = string.Format("x={0:0000}; y={1:0000}", e.X, e.Y);
if (mouseDownMove == 2)
{
LogMList(string.Format("\nx={0:0000} y={1:0000}", e.X, e.Y));
}
}
private void OnMouseDown(object sender, MouseEventArgs e)
{
Log(string.Format("MouseDown \t\t {0}\n", e.Button));
LogMousePosition(string.Format("\n\nx={0:0000}\ny={1:0000}", e.X, e.Y));
if (lastX != -100 && lastY != -100)
{
shortestDistanse = Convert.ToInt64(Math.Sqrt((Math.Pow(e.X - lastX, 2)) + (Math.Pow(e.Y - lastY, 2))));
LogMousePosition(string.Format("\nshortDistanse\t\t {0}\n", shortestDistanse));
LogMList(string.Format("\n\n NEW CLICK\n\nx={0:0000} y={1:0000}", e.X, e.Y));
}
lastX = e.X;
lastY = e.Y;
mouseDownMove = 2;
}
I have a form which can be moved when the user clicks and drags in a border area. The implementations I've seen all lock to the current mouse position, so that when the form is moved, the form jumps so that the mouse is in the upper-left corner. I'd like to change it so that it behaves like a normal windows form, and the form stays at the same position relative to the mouse when moved. My current code looks like this:
Point locationClicked;
bool isMouseDown = false;
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
isMouseDown = true;
locationClicked = new Point(e.Location.X, e.Location.Y);
}
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
isMouseDown = false;
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (isMouseDown && targetCell == new Point(-1, -1) && (mouseLocation.X < margin.X || mouseLocation.Y < margin.Y ||
mouseLocation.X > margin.X + cellSize.Width * gridSize.Width ||
mouseLocation.Y > margin.Y + cellSize.Height * gridSize.Height))
{
this.Location = new Point(e.Location.X - locationClicked.X, e.Location.Y - locationClicked.Y);
}
}
When I drag the window, it behaves similarly to what I want. The form flickers between two locations on the screen, one of which moves at about half the rate of the mouse. Is there a way I can fix this?
Try this out...
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
Point locationClicked;
bool dragForm = false;
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
locationClicked = new Point(e.Location.X, e.Location.Y);
if (isMouseDown && targetCell == new Point(-1, -1) && (mouseLocation.X < margin.X || mouseLocation.Y < margin.Y ||
mouseLocation.X > margin.X + cellSize.Width * gridSize.Width ||
mouseLocation.Y > margin.Y + cellSize.Height * gridSize.Height))
{
dragForm = true;
}
}
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (dragForm)
{
this.Location = new Point(this.Location.X + (e.X - locationClicked.X), this.Location.Y + (e.Y - locationClicked.Y));
}
}
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
dragForm = false;
}
}
I wrote this code:
private struct MovePoint
{
public int X;
public int Y;
}
private void Image_MouseDown(object sender, MouseEventArgs e)
{
FirstPoint = new MovePoint();
FirstPoint.X = e.X;
FirstPoint.Y = e.Y;
}
private void Image_MouseMove(object sender, MouseEventArgs e)
{
if(e.Button == MouseButtons.Left)
{
if(FirstPoint.X > e.X)
{
Rectangle.X = FirstPoint.X - e.X;
//Rectangle.Width -= FirstPoint.X - e.X;
} else
{
Rectangle.X = FirstPoint.X + e.X;
//Rectangle.Width += FirstPoint.X + e.X;
}
if(FirstPoint.Y > e.Y)
{
Rectangle.Y = FirstPoint.Y - e.Y;
//Rectangle.Height -= FirstPoint.Y - e.Y;
} else
{
Rectangle.Y = FirstPoint.Y + e.Y;
//Rectangle.Height += FirstPoint.Y + e.Y;
}
Image.Invalidate();
}
}
private void Image_Paint(object sender, PaintEventArgs e)
{
if(Pen != null) e.Graphics.DrawRectangle(Pen, Rectangle);
}
Rectangle moves, but with inversion (it should not be). Can you help?
The mathematics in your mouse-move handler for moving the rectangle based on the mouse-movements seems quite off; I think you want something like this:
private void Image_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
int initialX = 0, initialY = 0; // for example.
Rectangle.X = (e.X - FirstPoint.X) + initialX;
Rectangle.Y = (e.Y - FirstPoint.Y) + initialY;
Image.Invalidate();
}
}
This way, the rectangle's upper left corner will follow the mouse by tracking the delta between the initial mouse-down location and the current mouse location. Note however that each time you re-click and drag, the rectangle will move back to its original location.
If, instead, you want the Rectangle to 'remember' its position across multiple click-and-drag operations (i.e. not to be reinitialized to its initial location on mouse-down) you can do:
private void Image_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
// Increment rectangle-location by mouse-location delta.
Rectangle.X += e.X - FirstPoint.X;
Rectangle.Y += e.Y - FirstPoint.Y;
// Re-calibrate on each move operation.
FirstPoint = new MovePoint { X = e.X, Y = e.Y };
Image.Invalidate();
}
}
One other suggestion: There's no need to create your own MovePoint type when there's already the System.Drawing.Point type. Also, in general, try not to create mutable structs.