As the title suggests i am having trouble getting a DragOver event to function correctly. I have over 100 buttons on a form and i want their colour to change when a picturebox is dragged over them. I have set all buttons AllowDrop = true and have included the code below in the method.
private void ShipOver(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.None;
Button b = (Button)sender;
b.BackColor = Color.Green;
label22.Text = "";
}
I do not see why this will not work. I also have a DragLeave method which simply changes the colour to a different one.
One thing to note is that the item i am dragging over the button is larger than the button itself. Not sure whether this will have an effect.
You need to wire up the events to your method. If all of the buttons are in a single panel, you can do something like this in your form's constructor:
foreach (Button b in panel1.Controls.OfType<Button>()) {
b.DragOver += ShipOver;
}
Same principle applies to the DragLeave event.
Related
I get this very annoying border when pressing tab and the clicking the button
I've tried
foreach (Control x in this.Controls)
{
if (x is Button)
{
Button newbut = (Button)x;
newbut.FlatStyle = FlatStyle.Flat;
newbut.FlatAppearance.BorderColor = Color.FromArgb(0, 255, 255, 255);
newbut.FlatAppearance.BorderSize = 0;
newbut.TabStop = false;
}
}
And I've also tried doing adding an event on Keydown and not allowing to press the tab key but nothing has worked so far.
this is example of the border that keeps popping up
Fixed by generating own button class and editing the designer.cs file
If you do not want custom buttons, you can shift focus to another control once finished, this prevents the rectangle from showing. You could place a dummy control out of view and shift fucus to this.
private void btnDoSomething_Click(object sender, EventArgs e)
{
myDummyControl.Focus();
MessageBox.Show("This still executes even though we have lost focus");
// If you are decoupling your code from the UI, this becomes second nature quickly as it becomes part of your control handling.
}
Also you can stop the control from getting Tab focus my setting it's TabStop property tp false, do this in the buttons Paint event.
If you have many buttons, you can just point them to the same event handler (On_Paint).
private void On_Paint(object sender, PaintEventArgs e)
{
Button thisButton = sender as Button;
thisButton.TabStop = false;
}
To show the relevant information(in monopoly game, the property belongs which player, current market price etc.), I put a Label on the top of a panel, and used a ToolTip object to display the information. This is the image of my current setup.
Here are the steps I have done:
1.Added MouseHover event handler (The Label name is MEDITERANEAN)
this.MEDITERANEAN.MouseHover += new System.EventHandler(this.MEDITERANEAN_MouseHover);
2.Initialized Tooltip
private void InitializeToolTip()
{
toolTipLabel.ToolTipIcon = ToolTipIcon.Info;
toolTipLabel.IsBalloon = true;
toolTipLabel.ShowAlways = true;
}
3.Call setToolTip() in MouseHover call back function
private void MEDITERANEAN_MouseHover(object sender, EventArgs e)
{
toolTipLabel.SetToolTip(MEDITERANEAN, "You put mouse over me");
rolledDice.AppendText("Mouse Over");
}
But when I start application and move my cursor over the label, there is no text from toolTipLabel. What part did I make mistakes?
Interestingly, i made other function and it works.
private void panelBoard_MouseOver(object sender, EventArgs e)
{
toolTipLabel.SetToolTip(panelBoard, "You put mouse over me");
rolledDice.AppendText("Mouse Over");
}
I think you just need to bring your lable control in front of image. Try something like this .
MEDITERANEAN.BringToFront();
I found the solution, first I should set Panel's property "Enable" to true, then set label's property "visible" to true as well.
I have basically two controls involved in a drag/drop operation. I do this for the start control:
private void controlA_MouseMove(object sender, MouseEventsArgs e)
{
if(e.LeftButton == MouseButtonState.Pressed)
{
//set DataObject...datao
DragDrop.DoDragDrop(controlB, datao, DragDropEffects.Copy | DragDropEffects.Copy;
}
}
The user moves off of controlA, onto controlB and continues dragging to some point on controlB. I've tried the following in several events with no luck to establish a different cursor from the default arrow with the little box under it:
Mouse.OverrideCursor = Cursors.Hand;
and
Mouse.SetCursor(Cursors.Hand);
In these events for controlB, which is where the drop happens:
DragOver
DragEnter
GiveFeedback
How do I get rid of the default arrow with the little box under it while dragging over controlB?
Set ControlB.Cursor = Cursors.Whatever; inside your ControB_MouseEnter() event handler.
You may want to limit it under an if(e.LeftButton == MouseButtonState.Pressed) condition.
Tested MouseEnter while MouseLeftButton is Pressed:
I'm making a settings form, where user can assign custom hotkeys for the application. There's a TextBox, and by clicking it with mouse, it focuses and waits for one keypress and then defocuses (by focusing another label):
private void txtKey_KeyDown(object sender, KeyEventArgs e)
{
e.SuppressKeyPress = true;
}
private void txtKey_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
TextBox textBox = (TextBox)sender;
textBox.Text = e.KeyCode.ToString();
label1.Focus();
}
Is there a way to defocus focused TextBox (and cancel the key assinging process), by either clicking it again with mouse, or by clicking the GroupBox around it? I can't figure out how to check if TextBox was already focused when clicked (because when clicked, it gets focused before I can test if it's focused). Of course I can add a button "Cancel" next to the TextBox, but that's not what I want.
There is no Click-event for GroupBox, so I can't defocus TextBox by clicking GroupBox around it. Or can I somehow?
You can set/remove the Focus with
Keyboard.Focus = null;
You can also register to the following event:
public event MouseButtonEventHandler PreviewMouseLeftButtonDown
This event fires every time you click on the TextBox, thus you can set the Focus there if you want to.
For Winforms there is a way as well. I'm not proficient in it, but here would be a way:
Make a textBox (e.g. named textBoxFocus) that lies outside your window. Size it 1, 1 and move it to -10,-10 for example. Then you can register to the Click event and write
textBoxFocus.Focus();
It's a bit of a roundabout way, but should achieve what you want.
Thanks to private_meta for getting me to right direction (in comments)! I set the flag with click event, and before setting the flag, testing if flag is set. So first click does not find the flag, but second will. And flag is cleared within textbox Enter-event (which fires before Click-event). Now every other click focuses and every other defocuses textbox, as I wanted.
private void txtKey_Enter(object sender, EventArgs e)
{
TextBox textBox = (TextBox)sender;
textBox.Tag = null;
}
private void txtKey_Click(object sender, EventArgs e)
{
TextBox textBox = (TextBox)sender;
if (textBox.Tag != null) label1.Focus();
textBox.Tag = "clicked";
}
One of the simple way is that, you may use a bool flag here.
Algorithm:
By default, the bool value is 0;
If(Textbox Selected && flag = 0)
Do your task; and flag = 1;
I hope I could satisfy your query and you can follow this algorithm.
I just started programming, and I want to use WinForms to make multiple buttons that you can click on to change from white to lime-green and back to white. I have done this for one button:
private void button1_Click(object sender, EventArgs e)
{
if (button1.BackColor != Color.Lime)
{
button1.BackColor = Color.Lime;
}
else
{
button1.BackColor = Color.White;
}
}
Now I could copy and paste that for all of the buttons, but I know that is inefficient; and if I use winforms to reference button1 on button2, it will just change the color of button1 (obviously).
So, do I need to use a helper method, new class, or something else? What would that look like?
There are a couple of approaches. One might be to create a common function which the different buttons call:
private void button1_Click(object sender, EventArgs e)
{
ChangeColor(button1);
}
private void ChangeColor(Button button)
{
if (button.BackColor != Color.Lime)
button.BackColor = Color.Lime;
else
button.BackColor = Color.White;
}
Then each button handler can use that same function call.
Or, if all of these buttons will always ever do exactly the same thing, then you can use one click handler function for all of them. In this case what you'd need to do is determine which button invoked the handler (whereas you're currently referencing button1 directly) so that you know which one to change. The sender object passed into the handler function is actually a reference to the form element which invoked the handler. All you need to do is cast it:
private void button_Click(object sender, EventArgs e)
{
var button = (Button)sender;
if (button.BackColor != Color.Lime)
button.BackColor = Color.Lime;
else
button.BackColor = Color.White;
}
So first the handler grabs a reference to the button which invoked it, then runs the logic on that button. Note also how I made the name of the handler function slightly more generic. Now you'd go to the form designer and set button_Click as the click handler for all of the buttons which should invoke this.
You do this the exact same way you'd do it for any C# class. You derive your own class and customize the base class behavior. Every event has a corresponding OnXxxx() method that you can override.
Add a new class to your project and paste this code:
using System;
using System.Windows.Forms;
class MyButton : Button {
protected override void OnClick(EventArgs e) {
// Your code here
//...
base.OnClick(e);
}
}
Change the code in OnClick() to do what you want to do. Compile. You'll now have your own button control on the top of the toolbox. And can drop as many copies of it as you want on a form. They'll all behave the same without having to add any code in the form.
Probably the easiest way would be to have each button invoke the same click handler. Then inside of your handler use the Sender instead of hard coding Button1.
private void buttons_Click(object sender, EventArgs e)
{
var theButton = (Button) sender;
if (theButton.BackColor != Color.Lime)
{
theButton.BackColor = Color.Lime;
}
else
{
theButton.BackColor = Color.White;
}
}
You can get the button that raised the Click event by casting sender to Button.
You can then add the same handler to every button.
I'm a VB guy.... in VB.Net you can add multiple handlers for events and connect multiple events to the same handler.
This sub hooks all clicks to color the buttons.
Private Sub ColorButtons(sender As System.Object, e As System.EventArgs) _
Handles Button1.Click, Button2.Click, ..
I do this all the time accidentally because I drag/copy a control to make a new one and the new button gets added to the original's events.
Other Subs can handle the same events to do other work - both will execute.
No idea how to do this in C#.
The proper way to do this really is to associate each button's click event to the function you have coded for that purpose (you want the function to run when the button is clicked, right?), so add the following (or similar) to an appropriate section of your code:
MyButton1.Click += new RoutedEventHandler(buttons_Click);
MyButton2.Click += new RoutedEventHandler(buttons_Click);
etc...
You can associate as many controls to the event handler as you like.
What I usually do before is this:
private void button2_Click(object sender, EventArgs e)
{
button1.PerformClick();
}
This code will just simply run the codes under button1_Click.
But try not to practice as such and just simply put it in a function/method just like what David suggested.