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How to cancel the ValueChanged event for NumericUpDown controls?

Under certain conditions I'd like to cancel the ValueChanged event of a NumericUpDown control in Winforms (e.g. when the value set in the control is too high in relation to another value in a TextBox).
However, the EventArgs passed as argument into the event handler for the NumericUpDown control doesn't offer anything like "Cancel", so how can I do it?
private void nudMyControl_ValueChanged(object sender, EventArgs e)
{
// Do some stuff, but only if the value is within a certain range.
// Otherwise, cancel without doing anything.
}

You probably can handle this situation by using Minimum & maximum Properties, yet there are some solutions.
One way to do it is by creating a custom control, although it is nasty in my idea.
public partial class CustomNumericUpDown : NumericUpDown
{
public CustomNumericUpDown()
{
InitializeComponent();
}
protected override void OnTextBoxKeyDown(object source, KeyEventArgs e)
{
if (MyCustomCondition())
{
e.Handled = true;
}
base.OnTextBoxKeyDown(source, e);
}
private bool MyCustomCondition()
{
var checkOut = false;
//if (something == foo)
//{
checkOut = true;
//}
return checkOut;
}
}
You also can do stuff for ValueChanged:
This is some dummy sample, yet you can change it in your way:
public virtual decimal CurrentEditValue { get; internal set; } = 0M;
protected override void OnTextChanged(EventArgs e)
{
base.OnTextChanged(e);
if (decimal.TryParse(Text, out decimal v))
{
CurrentEditValue = v;
OnValueChanged(e);
}
}
protected override void OnValueChanged(EventArgs e)
{
// if(CurrentEditValue == foo) Do_stuff.
base.OnValueChanged(e);
}

Using Double Right Click in C#

I am fairly new with C# and I want to know if there is a way to implement a double right click in this event handler? Can anyone tell me how? thanks
private void pictureBox_MouseClick(object sender, MouseEventArgs e){
if(e.Button == MouseButtons.Left)
{
MessageBox.Show("A");
}
else if(e.Button = MouseButtons.Right)
{
MessageBox.Show("B");
}
else if(e.Button = MouseDoubleClick.Right) <--how to fix this?
{
MessageBox.Show("C");
}
else
{
MessageBox.Show("D");
}
}

You can use the ClickCount propery of MouseRightButtonDown event.
private void OnMouseDownClickCount(object sender, MouseButtonEventArgs e)
{
if (e.ClickCount == 1)
{
// one click.
}
if (e.ClickCount == 2)
{
// two clicks.
}
}

Override the WndProc function and listen for WM_RBUTTONDBLCLK, which as can be seen on this pinvoke page is {0x0206}.
Then
public class RButton : Button
{
public delegate void MouseDoubleRightClick(object sender, MouseEventArgs e);
public event MouseDoubleRightClick DoubleRightClick;
protected override void WndProc(ref Message m)
{
const Int32 WM_RBUTTONDBLCLK = 0x0206;
if (m.Msg == WM_RBUTTONDBLCLK)
DoubleRightClick(this, null);
base.WndProc(ref m);
}
}

How to override Control.Invalidate() method?

I use OwnerDrawAll properties for my control:
this.customTreeView.DrawMode =System.Windows.Forms.TreeViewDrawMode.OwnerDrawAll;
this.customTreeView.DrawNode +=
new System.Windows.Forms.DrawTreeNodeEventHandler(customTreeView_DrawNode);
private void customTreeView_DrawNode(object sender, DrawTreeNodeEventArgs e) {
if(!myComboBoxChanged) { // Draw the whole control(tree and info)
drawNode(e);
drawInfo(e);
} else { // Draw only info
drawInfo(e);
}
}
Then I use text changed event:
private void cBox_TextChanged(object sender, EventArgs e)
{
text = cBox.Text; // I need this in drawInfo()
myComboBoxChanged = true;
this.customTreeView.Invalidate(); // It doesn't do what I want
myComboBoxChanged = false;
}
Here Invalidate() method redrawing the whole tree, how can I fix this so only drawInfo() will be called ?

the better way is to create your own TreeView Class and encapsulate all of your methods and properties so :
public class MyTreeView : TreeView
{
public bool TextBoxChanged { get; set; }
public MyTreeView()
{
DrawMode = TreeViewDrawMode.OwnerDrawAll;
DrawNode += new System.Windows.Forms.DrawTreeNodeEventHandler(customTreeView_DrawNode);
}
protected override void OnInvalidated(InvalidateEventArgs e)
{
//comment the below line to create your own Invalidate
//base.OnInvalidated(e);
}
private void customTreeView_DrawNode(object sender, DrawTreeNodeEventArgs e)
{
if (!TextBoxChanged)
{ // Draw the whole control(tree and info)
drawNode(e);
drawInfo(e);
}
else
{ // Draw only info
drawInfo(e);
}
}
private void drawNode(DrawTreeNodeEventArgs e)
{
//...........
}
private void drawInfo(DrawTreeNodeEventArgs e)
{
//...........
}
}

Can I get a MouseLeave event while Mouse.Capture() is active?

I have a button. On Button.MouseRightButtonDown, I'm calling Mouse.Capture(button), because I want to detect if someone releases right-click outside of the Button.
I also have a Button.MouseLeave event registered. If someone right-click-drags the mouse off the button, I want this event to trigger.
Unfortunately, it seems like Mouse.Capture somehow blocks MouseLeave from occuring.
Does anyone know a workaround, or maybe can point out where I'm going wrong?
(By the way, if anyone's curious what I'm doing this for, see my other question.)

When mouse is captured, you can use MouseMove and hit-testing to determine whether the mouse within your element or another.
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
if (this.IsMouseCaptured)
{
HitTestResult ht = VisualTreeHelper.HitTest(this, e.GetPosition(this));
if (ht != null)
{
DependencyObject current = ht.VisualHit;
while (current != this && current != null)
{
current = VisualTreeHelper.GetParent(current);
}
if (current == this)
{
Debug.WriteLine("Inside");
return;
}
}
Debug.WriteLine("Outside");
}
}
The following code can be used to avoid tree walk:
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
if (this.IsMouseCaptured)
{
bool isInside = false;
VisualTreeHelper.HitTest(
this,
d =>
{
if (d == this)
{
isInside = true;
}
return HitTestFilterBehavior.Stop;
},
ht => HitTestResultBehavior.Stop,
new PointHitTestParameters(e.GetPosition(this)));
if (isInside)
{
Debug.WriteLine("Inside");
}
else
{
Debug.WriteLine("Outside");
}
}
}

Following on from my answer to your related question, if you use CaptureMouse() from UIElement in place of Mouse.Capture(...) then you will see the correct behaviour.
public class MyButton : Button
{
protected override void OnMouseRightButtonDown(MouseButtonEventArgs e)
{
base.OnMouseRightButtonDown(e);
CaptureMouse();
}
protected override void OnMouseRightButtonUp(MouseButtonEventArgs e)
{
base.OnMouseRightButtonUp(e);
ReleaseMouseCapture();
}
protected override void OnMouseEnter(MouseEventArgs e)
{
base.OnMouseEnter(e);
Debug.WriteLine("Mouse enter");
}
protected override void OnMouseLeave(MouseEventArgs e)
{
base.OnMouseLeave(e);
Debug.WriteLine("Mouse leave");
}
}

Raising an event on user control from parent

I have a user control that has the following overridden event:
protected override void OnKeyDown(KeyEventArgs e)
{
if (e.KeyCode == Keys.Left )
DoSomething();
}
When I place the user control on my Main Form, this event is not fired.
How can I access this event from Parent form?
protected override void OnKeyDown(KeyEventArgs e)
{
e.Handled = true;
if (e.KeyCode == Keys.Left)
Move(pt.X,pt.Y);//Move is a function within the usercontrol
else if (e.KeyCode == Keys.Right)
Move(pt.X,pt.Y);
//other conditions
e.Handled = false;
}
I need the parent to be notified on this event

If I understand correctly, you are trying to invoke the OnKeyDown method of the user control from within the parent form.
This is the main form class:
public class Form1 : Form
{
private UserControl1 myControl;
public Form1()
{
myControl = new UserControl1();
Controls.Add(myControl);
}
protected override void OnKeyDown(KeyEventArgs e)
{
base.OnKeyDown(e);
myControl.InvokeOnKeyDown(e);
}
}
And this is the User Control:
public class UserControl1 : UserControl
{
protected override void OnKeyDown(KeyEventArgs e)
{
base.OnKeyDown(e);
MessageBox.Show("Key Down Fired!");
}
public void InvokeOnKeyDown(KeyEventArgs e)
{
OnKeyDown(e);
}
}
Edit regarding arrow keys: the arrow keys are not normally considered to be input keys and therefore are not passed on to the key methods. To change this you must override the IsInputKey method as such:
protected override bool IsInputKey(Keys e)
{
if (e == Keys.Up || e == Keys.Down ||
e == Keys.Left || e == Keys.Right) return true;
return base.IsInputKey(e);
}

Following your updated question and code example posted, if you want the parent Form to be notified that a move operation took place, you need to create an event in the UserControl and subscribe to it in the parent form. This could be achieved in the following example. Please let me know if this solves your problem, else please post further detail.
Best regards
// Define custom EventArgs to pass into the Move event
public class MoveEventArgs : EventArgs
{
private Point _movePoint;
public MoveEventArgs(Point movePoint)
{
_movePoint = _movePoint;
}
public Point MovePoint { get { return _movePoint; } }
}
// Define a custom user control that raises an event to subscribers on move
public class MyUserControl : UserControl
{
public event EventHandler<MoveEventArgs> Moved;
protected override void OnKeyDown(KeyEventArgs e)
{
e.Handled = true;
if (e.KeyCode == Keys.Left)
{
Move(pt.X,pt.Y);//Move is a function within the usercontrol
OnMoved(pt);
}
else if (e.KeyCode == Keys.Right)
{
Move(pt.X,pt.Y);
OnMoved(pt);
}
//other conditions
e.Handled = false;
}
// Raises a custom event, Moved
protected void OnMoved(Point movePoint)
{
var handler = Moved;
if (handler != null)
{
handler(this, new MoveEventArgs(movePoint);
}
}
}
// How to subscribe to the event (and be notified of move)
public class MyParentForm : Form
{
public MyParentForm()
{
InitializeComponent();
_myUserControl.Moved += new EventHandler<MoveEventArgs>(MyUserControl_Moved);
}
private void MyUserControl_Moved(object sender, MoveEventArgs e)
{
// e.MovePoint now contains the point that the usercontrol was moved to
// this event will fire whenever the user presses Left or Right arrow
}
}