I had written an event handler for MouseMove for my form
but When I add a panel to form, this handler does NOT run while mouse moves on panel.
I added event handler to panel and this works but I had several panels on the form,
is there an easier solution?
Unfortunately, WinForms doesn't support event bubbling. But you can write some code to ease the task of hooking up events.
public void AssignMouseMoveEvent(Form form)
{
foreach(Control control in form.Controls)
{
if(! (control is Panel))
continue;
control.MouseMove += PanelMouseMove;
}
}
You should call the above code passing it your current form and it will assign PanelMouseMove as event handler for MouseMove event of all the panels.
I think you should be able to "propagate" the handlers, so you don't have to re-write the code in each one. Just remember that the MouseMove event has control-relative coordinates, so if you pass the event from your panel to your form, you'll have to translate the X & Y values in the event to the form coordinates (something like subtracting panel.location.X from event.X, etc).
This code worked for me (assumes you have a form with a panel and a label. The label is named "MouseCoords"
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace WindowsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void ShowCoords(int x, int y)
{
this.MouseCoords.Text = string.Format("({0}, {1})", x, y);
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
this.ShowCoords(e.X, e.Y);
}
protected override void OnControlAdded(ControlEventArgs e)
{
// hook the mouse move of any control that is added to the form
base.OnControlAdded(e);
e.Control.MouseMove += new MouseEventHandler(Control_MouseMove);
}
private void Control_MouseMove(object sender, MouseEventArgs e)
{
// convert the mouse coords from control codes to screen coords
// and then to form coords
System.Windows.Forms.Control ctrl = (System.Windows.Forms.Control)sender;
Point pt = this.PointToClient(ctrl.PointToScreen(e.Location));
this.ShowCoords(pt.X, pt.Y);
}
private void Form1_Load(object sender, EventArgs e)
{
this.MouseMove += this.Form1_MouseMove;
}
}
}
You could Implement IMessageFilter to pre-process messages that are going to your controls.
http://blogs.msdn.com/csharpfaq/archive/2004/10/20/245412.aspx
However, I don't think this is a very clean way to do things from a design perspective.
No there is no simpler way, and you should assign event handler for each control where you need to receive MouseMove events.
If you set the Capture property of the form to true, it will receive all mouse input, regardless of which control that is under the mouse. It will lose the mouse capture at certain operations (I am not sure exactly when, though). Also, according to the documentation for the property, shortcut keys should not work while the mouse is captured. So, depending on what you want to achieve, this might not be the preferred way to go.
Assuming that mouse starts moving over the form rather than over the panel - which is a big assumption - you'll get a MouseLeave event when it enters a sub control. You could check the cursor location and call the mouse move code if it's still within the bounds of the form.
This doesn't work if the mouse move event starts on a control.
I found another solution :) "Raise events in controls which hide events"
I catch the event in panel and rise the Mouse move event of the form by calling onMouseMove
Related
I have Windows Form TestForm, and in my Form I have several labels that are only used to display some text.
I need to display a MessageBox.Show anytime the Form is clicked. So I have an event handler for the click, which looks like this:
private void TestForm_Click(object sender, EventArgs e)
{
MessageBox.Show("The form has been clicked");
}
Unfortunately, the click event doesn't fire when I click over a label in the Form. Is there a way to fix this, besides consuming the click event for the labels?
Thanks.
To use the same click event for all labels:
In the properties for each label, go to the Events (lightning bolt tab).
You will see (probably near the top) a label for Click, click the dropdown for this event, and you will be shown a list of handlers that you could use for that label.
Here's the Properties > Events > Click handler (bottom right):
Because all of your labels are of the same type, and produce the same EventArgs, you are able to use the same handler for all of them.
Then, when you are adding more Labels, just choose the event handler from the Click event dropdown:
Hope this helps!
To flesh out LarsTech's comment, I have used something like this in the past when I was having problems with labels overlapping each other and lack of true transparency in WinForms. What I did was make the labels invisible on the Form, then iterate through them in the Form's paint event, pull the information out of them and then use Graphics.DrawString to draw the text. That way you you will still be able see them in design mode.
This is a quick example of what I mean.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
foreach (var temp in this.Controls)
{
if (temp is Label) //Verify that control is a label
{
Label lbl =(Label)temp;
e.Graphics.DrawString(lbl.Text, lbl.Font, new SolidBrush(lbl.ForeColor), new Rectangle(lbl.Location, lbl.Size));
}
}
}
private void Form1_Click(object sender, EventArgs e)
{
MessageBox.Show("The Form has been clicked");
}
}
This question is related to this my question. Now I have form in my class and when user click on button I show (or hide) form. That´s ok. But I want to hide form when I move with origin form or when I click somewhere in origin form. The new form is behind that origin form. I was trying events like lostfocus and others but It didn´t help. So I think I need some trick that check from my control if there was click in parrent form (origin form) or some other hack. I know the best would be that I put code but I have many lines so I think that best way will be if you help me in general way and then I try to applicate to my app.
You can do it with a global mouse and keyboard hook. In fact, its been wrapped up into well documented, well structured .NET API over at CodePlex
Go over there and download it. Then, set up a global mouse hook:
_mouseListener = new MouseHookListener(new GlobalHooker());
_mouseListener.MouseMove += HandleGlobalHookMouseMove;
_mouseListener.Start();
The key here is that you will receive the MouseMove event ANY time the mouse moves ANYWHERE on the desktop, not just within the bounds of your window.
private void HandleAppHookMouseMove(object sender, MouseEventArgs e)
{
if (this.Bounds.Contains(e.Location))
{
HandleEnter();
}
else
{
HandleLeave();
}
}
You can also setup one for MouseClick. The combination of the two will enable you to determine any time the mouse moves over your origin form, or the mouse is clicked when its over it. Unlike the LostFocus and other events you tried, focus is irrelevant.
Does below help?
public partial class Form1 : Form
{
Form f2 = new Form2();
public Form1()
{
InitializeComponent();
f2.Show();
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (this.ClientRectangle.Contains(e.Location) && f2.Visible) { f2.Hide(); }
}
private void button1_Click(object sender, EventArgs e)
{
f2.Visible = !f2.Visible ? true : false;
}
}
How do I know when the image of the picturebox change?
Is there an event for an image change?
using System;
using System.Windows.Forms;
using System.Drawing;
namespace CustomPX
{
public class CustomPictureBox : PictureBox
{
public event EventHandler ImageChanged;
public Image Image
{
get
{
return base.Image;
}
set
{
base.Image = value;
if (this.ImageChanged != null)
this.ImageChanged(this, new EventArgs());
}
}
}
}
You can add this Class into ToolBox and/or from code and use ImageChanged event to catch if Image is Changed
First make sure that the images are loaded asynchronously. To do this set the PictureBox's WaitOnLoad property to false (which is the default value).
pictureBox1.WaitOnLoad = false;
Then load the image asynchronously:
pictureBox1.LoadAsync("neutrinos.gif");
Create an event handler for the PictureBox's LoadCompleted event. This event is triggered when the asynchronous image-load operation is completed, canceled, or caused an exception.
pictureBox1.LoadCompleted += PictureBox1_LoadCompleted;
private void PictureBox1_LoadCompleted(Object sender, AsyncCompletedEventArgs e)
{
//...
}
You can find more information about this event on MSDN:
http://msdn.microsoft.com/en-us/library/system.windows.forms.picturebox.loadcompleted.aspx
There are load events if you use Load() or LoadAsync(), but not for the Image property. This is explicitly set by you (the developer) and is generally speaking in 100% of your control (see notation below). If you really wanted to though (there isn't really a point, though), you can derive your own UserControl from PictureBox and override the Image property, and implement your own event handler.
Notation
I suppose one event you would want an event to subscribe to is if you are using some third-party component or control that changes the image property, and you want to implement some sort of sub routine when this happens. In this event it would be a reason to need a ImageChanged event since you don't have control over when the image is set. Unfortunately there still isn't a way to circumvent this scenario.
The Paint event is working:
private void pictureBox_Paint(object sender, PaintEventArgs e)
{
// image has changed
}
The program should draw a rectangle on click. But it does not. Maybe some problem with my understanding of delegates. What's the catch?
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
namespace forms1
{
public partial class MainForm : Form
{
public MainForm()
{
//
// The InitializeComponent() call is required for Windows Forms designer support.
//
InitializeComponent();
//this.Paint+= new PaintEventHandler(MujPaintHandler);
this.Click += new EventHandler(MujClickHandler);
}
public void MujPaintHandler(object sender,PaintEventArgs e)
{
Graphics gfx=e.Graphics;
gfx.FillRectangle(new SolidBrush(Color.DarkViolet),100,100,200,200);
}
public void MujClickHandler(object sender,EventArgs e)
{
this.Text="aaaaa";
this.Paint+= new PaintEventHandler(MujPaintHandler);
}
}
}
The code you've written works for me, but your form's window has to be big enough to show the rectangle.
Diagnostically, the first thing I'd check is whether the title of the form changes to "aaaaa". If it does, then you know the click handler is being called - but maybe you've got a problem with the paint handler. If it doesn't, then for some reason your click handler isn't being called.
Note that this isn't the normal way you'd draw a rectangle on a click in Windows Forms, but I'm assuming this is just a learning exercise.
Try forcing a redraw after assigning the event handler:
public void MujClickHandler(object sender,EventArgs e)
{
this.Text="aaaaa";
this.Paint+= new PaintEventHandler(MujPaintHandler);
this.Invalidate();
}
Also, if you click twice, the event handler gets assigned twice, which is not something you want.
Maybe you have to force a redraw. Does the rect appear if you move the window? Just call the PaintHandler after click.
I think you are only attaching the Paint event handler. You are not invoking the Paint event.
Try this
public void MujClickHandler(object sender,EventArgs e)
{
this.Text="aaaaa";
this.Paint+= new PaintEventHandler(MujPaintHandler);
this.Invalidate();
}
It will only draw the rectangle if it happens to be inside the area that is invalidated to update the text that you change.
When you change the text, it creates a message that the text has to be redrawn, which will call the Paint event to do the drawing. The event will have a Graphics object that is clipped to the rectangle that needs to be redrawn to update the text, so only the part of the rectangle that intersects with the text will be drawn.
You have to cause a redraw that covers the entire rectangle, so the easiest is to cause the whole window to be redrawn:
this.Invalidate();
Note that you should not hook up the Paint event from the Click event handler. That means that the event will be hooked up one more time each click, so after five clicks the Paint event handler will be called five times every time something needs to be redrawn.
Looking at your code, I understand that you are trying to add an eventhandler for paint event on Click... You would also need to invoke the paint event.. Here is a sample code where I am assigning the Paint EventHandler on a button click and raising the paint event on the click as you are doing
public Form1()
{
InitializeComponent();
this.Click += new EventHandler(MujClickHandler);
}
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.ControlKey)
{
MessageBox.Show(e.KeyCode.ToString());
}
}
private void Form1_Load(object sender, EventArgs e)
{
//this.Paint += new PaintEventHandler(MujPaintHandler);
}
public void MujPaintHandler(object sender,PaintEventArgs e)
{
Graphics gfx=e.Graphics;
gfx.FillRectangle(new SolidBrush(Color.DarkViolet),100,100,200,200);
}
public void MujClickHandler(object sender,EventArgs e)
{
this.Text="aaaaa";
this.RaisePaintEvent(this, new PaintEventArgs(this.CreateGraphics(), this.RectangleToClient(new Rectangle())));
}
private void button1_Click(object sender, EventArgs e)
{
this.Paint += new PaintEventHandler(MujPaintHandler);
}
I have a c# form (let's call it MainForm) with a number of custom controls on it. I'd like to have the MainForm.OnClick() method fire anytime someone clicks on the form regardless of whether the click happened on the form or if the click was on one of the custom controls. I'm looking for behavior similar to the KeyPreview feature of forms except for mouse clicks rather than key presses.
I recommend creating a base form for the other forms in your application to inherit. Add this code to your base form to create a new event called GlobalMouseClickEventHandler:
namespace Temp
{
public delegate void GlobalMouseClickEventHander(object sender, MouseEventArgs e);
public partial class TestForm : Form
{
[Category("Action")]
[Description("Fires when any control on the form is clicked.")]
public event GlobalMouseClickEventHander GlobalMouseClick;
public TestForm()
{
InitializeComponent();
BindControlMouseClicks(this);
}
private void BindControlMouseClicks(Control con)
{
con.MouseClick += delegate(object sender, MouseEventArgs e)
{
TriggerMouseClicked(sender, e);
};
// bind to controls already added
foreach (Control i in con.Controls)
{
BindControlMouseClicks(i);
}
// bind to controls added in the future
con.ControlAdded += delegate(object sender, ControlEventArgs e)
{
BindControlMouseClicks(e.Control);
};
}
private void TriggerMouseClicked(object sender, MouseEventArgs e)
{
if (GlobalMouseClick != null)
{
GlobalMouseClick(sender, e);
}
}
}
}
This solution will work not only for top-level controls, but also nested controls such as controls placed inside of panels.
In the form's ControlAdded event, add a MouseClick handler to the control, with the Address of the form's click event. I haven't tested this, but it might work.
Private Sub Example_ControlAdded(ByVal sender As Object, ByVal e As System.Windows.Forms.ControlEventArgs) Handles Me.ControlAdded
AddHandler e.Control.MouseClick, AddressOf Example_MouseClick
End Sub
Private Sub Example_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseClick
MessageBox.Show("Click")
End Sub
The only way I've ever managed to do this is to handle the [c]Click[/c] event of every control. I don't believe the event is raised before the control processes it.
In WPF, there are "tunneling" preview events that provide this functionality, but that doesn't really help you in WinForms.
You can hook all the control's events, if you like, and then monitor that way. I assume there is some uber fancy Win32 api way to trap them all, but that is beyond me at the moment.
public Form1()
{
InitializeComponent();
HookEvents();
}
private void HookEvents() {
foreach (Control ctl in this.Controls) {
ctl.MouseClick += new MouseEventHandler(Form1_MouseClick);
}
}
void Form1_MouseClick(object sender, MouseEventArgs e)
{
LogEvent(sender, "MouseClick");
}
// and then this just logs to a multiline textbox you have somwhere on the form
private void LogEvent(object sender, string msg) {
this.textBox1.Text = string.Format("{0} {1} ({2}) \n {3}",
DateTime.Now.TimeOfDay.ToString(),
msg,
sender.GetType().Name,
textBox1.Text
);
}
The output is something like this, showing all the events and who "sent" them up:
14:51:42.3381985 MouseClick (Form1)
14:51:40.6194485 MouseClick (RichTextBox)
14:51:40.0100735 MouseClick (TextBox)
14:51:39.6194485 MouseClick (Form1)
14:51:39.2131985 MouseClick (RichTextBox)
14:51:38.8694485 MouseClick (Button)
HTH.
Catching a click on an open space on the form is easy, but to get a click that's actually on a control, you'll need the cooperation of that control to send it to the form.
One possibility is to place a transparent control over the entire form, and accept clicks onto that, deal with them, and then pass them onto the proper control underneath.
This is a common pattern in development, its called the Observer pattern. There are lots of examples of Observer patterns and c# here is 1 example http://msdn.microsoft.com/en-us/library/ms954621.aspx but have a good google around.