I've got a basic owner-drawn listview (in Details mode) set up with the following handlers:
void SinkHandlerDrawColumnHeader(Object Sender, DrawListViewColumnHeaderEventArgs E)
{
E.DrawDefault = true;
}
void SinkHandlerDrawItem(Object Sender, DrawListViewItemEventArgs E)
{
E.DrawDefault = true;
TrackingMessage Data = (TrackingMessage)E.Item.Tag;
E.Item.SubItems[0].Text = Data.Line().ToString();
E.Item.SubItems[1].Text = Data.Message();
}
void SinkHandlerDrawSubItem(Object Sender, DrawListViewSubItemEventArgs E)
{
E.DrawDefault = true;
}
While the above code works, the listview is constantly being redrawn whenever it's visible. Any idea why?
EDIT: The problem was with my modifying the subitem text inside the owner draw handler. Using E.Graphics.DrawString to render the text instead fixed the issue.
Per my comment, changing data in a paint event is usually a bad design. Paint events should just paint, and very little else. By changing the data in the paint event, you were forcing the paint event to draw itself again and again.
If you need to modify the data, you need a different event.
Related
I have a application that talks to the Database-API of a game and displays information about certain items. One part of the UI looks like this:
For the grey boxes I have created a control called 'ItemPreviewControl', which each show information about one specific found Item. I want the control to become red when hovered and return to gray when the mouse leaves the control. For this I have used the MouseEnter- and MouseLeave-Events of the ItemPreviewControl, and as you can see here it also works:
Here's the code I used:
private Color mainColor_MouseEnterLeave;
private void ItemPreviewControl_MouseEnter(object sender, EventArgs e)
{
mainColor_MouseEnterLeave = this.BackColor;
this.BackColor = Color.FromArgb(192, 0, 0);
}
private void ItemPreviewControl_MouseLeave(object sender, EventArgs e)
{
this.BackColor = mainColor_MouseEnterLeave;
}
Now the problem I have is the following: My 'ItemPreviewControl' also changes back to gray when I hovor above one of its child elemenets, so e.g. when I hover above the textboxes inside the control. But I want the control to stay red until I leave the actual control. Do you have any ideas of how to implement this?
The UI is a Windows Forms App. The UI as well as all the Backend-Libraries are in .NET Core 3.1.
Thank you for reading.
Edit: Solution for my problem:
It turns out I had to check whether the Mouse is still inside the UserControl's bounds. If yes, cancel the MouseLeave-Method with a return, and otherwise continue the method. Here's my updated code:
private void ItemPreviewControl_MouseEnter(object sender, EventArgs e)
{
this.BackColor = Color.FromArgb(192, 0, 0);
}
private void ItemPreviewControl_MouseLeave(object sender, EventArgs e)
{
if (this.ClientRectangle.Contains(this.PointToClient(MousePosition)))
return;
this.BackColor = Color.FromName("Gray");
}
I'd like to create a roulette game, and I've made a PictureBox with an image of a roulette table.
I've tried to set Visibility = False in the property and in code:
pictureBox1.Visible = !pictureBox1.Visible;
But when I click on the hidden PictureBox, nothing happens.
Do you have any idea how to make it work?
I want to make it visible from being invisible, by clicking on it.
Once you make the visibility of an Item false, it can no longer be clicked. You can handle the click event on the form or container level, check that the mouse coordinates are contained in the bounds of the PictureBox and use that to make it visible again.
i.e.
//Common eventhandler assigned to all of your PictureBox.Click Events
private void pictureBox_Click(object sender, EventArgs e)
{
((PictureBox)sender).Visible = false;
}
private void Form1_Click(object sender, EventArgs e)
{
foreach (var item in this.Controls) // or whatever your container control is
{
if(item is PictureBox)
{
PictureBox pb = (PictureBox)item;
if (pb.Bounds.Contains(PointToClient( MousePosition)))
{
pb.Visible = true;
}
}
}
}
Problem with your logic is that once the PictureBox is made invisible, you can no longer click it anymore, since it's no longer on the form, and while you can for sure click the empty space it left, you're still not clicking it.
A possibility would be to, instead of making visible/invisible, to put/remove its background picture, so it appears to have disappeared but in fact it's still there, still able to receive clicks and respond to events.
If you want to make the pictureBox1 not visible, you would write pictureBox1.Visible = false;
Edit: What you are doing should work. I created a winform and put a picture box in it. I double clicked the picture box to make Click event handler and typed pictureBox1.Visible = !pictureBox1.Visible;. When I debug the program and click on the picture box, it turns invisible. I can't think of why it isn't working for you.
Edit: I understand what you want now. To make it visible on the click of it when it is invisible. Unfortunately I don't know how to do that.
A maybe-silly but simple way might be to put one picture box on top of the other. pictureBox1 would be your picture, pictureBox2 would have no picture. Then you could do something like this:
private void pictureBox1_Click(object sender, EventArgs e)
{
pictureBox1.Visible = false;
pictureBox2.Visible = true;
}
private void pictureBox2_Click(object sender, EventArgs e)
{
pictureBox1.Visible = true;
pictureBox2.Visible = false;
}
You could put each of your PictureBox controls in a Panel control. Then handle the Click event of both the Panel and the PictureBox.
private void panel1_Click(object sender, EventArgs e)
{
pictureBox1.Visible = true;
}
private void pictureBox1_Click(object sender, EventArgs e)
{
pictureBox1.Visible = false;
}
I have the following problem: I have a panel which has a specific color, say red.
When the user presses his mouse, the color of this panel gets stored in a variable. Then the user moves, his mouse still pressed, over to another panel. When he releases the mouse there, this panel should get the background color of the first that had been stored in the variable. My code looks something like this:
public Color currentColor;
private void ColorPickMouseDown(object sender, MouseEventArgs e)
{
Panel pnlSender = (Panel)sender;
currentColor = pnlSender.BackColor;
}
private void AttempsColorChanger(object sender, MouseEventArgs e)
{
Panel pnl = (Panel)sender;
pnl.BackColor = currentColor;
}
I need to identify the sender first because there are many possible panels that can trigger this event. The first MouseDown method works totally fine, the color is stored nicely in the variable. The secon one however doesn't even get triggered when the user does what I described above. When the ser clicks on the second panel, it works (there is an MouseUp part in a click aswell I guess).
What's wrong here? Why is the event not triggered when the user holds the mouse key down before?
(This answer assumes you are using Windows Forms.)
It could be that you need to capture the mouse by setting this.Capture = true in the MouseDown of the source control. (See Control.Capture)
If you did that, the source window would get the MouseUp event, and it would be the source window that had to determine the destination window under the mouse coords. You can do that using Control.GetChildAtPoint() (see this answer on Stack Overflow).
Use Windows Forms Drag and Drop Support Instead! <- Click for more info
I'm going to suggest you bite the bullet and use the .Net Drag and Drop methods to do this. It requires some reading up, but it will be much better to use it.
You start a drag in response to a MouseDown event by calling Control.DoDragDrop().
Then you need to handle the Control.DragDrop event in the drop target control.
There's a few more things you might need to do to set it up; see the Control.DoDragDrop() documentation for an example.
(For WPF drag and drop support, see here.)
when your mouse enter the target control , mouse down triggerd ang get target BackColor! you need add an boolean flag to your code :
public Color currentColor;
bool flag=false;
private void ColorPickMouseDown(object sender, MouseEventArgs e)
{
if(flag==false)
{
flag=true
Panel pnlSender = (Panel)sender;
currentColor = pnlSender.BackColor;
}
}
//assume mouse up for panles
private void AttempsColorChanger(object sender, MouseEventArgs e)
{
if(flag==true)
{
Panel pnl = (Panel)sender;
pnl.BackColor = currentColor;
flag=flase;
}
}
and also you need change your flag in mouseMove( if )
As I mentioned in my comment Mouse Events are captured by the originating control, You would probably be better off using the DragDrop functionality built into Windows Forms. Something like this should work for you. I assigned common event handlers, so they can be assigned to all of your panels and just work.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void panel_MouseDown(object sender, MouseEventArgs e)
{
((Control)sender).DoDragDrop(((Control)sender).BackColor,DragDropEffects.All);
}
private void panel_DragDrop(object sender, DragEventArgs e)
{
((Control)sender).BackColor = (Color)e.Data.GetData(BackColor.GetType());
}
private void panel_DragEnter(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Copy;
}
}
I know it's an old question but I had the same issue and none of the above answers worked for me. In my case I had to handle the MouseMove event in the target control and check for the mouse to be released. I did set 'BringToFront' on my target panel just in case that helped at all.
public Color currentColor;
private void ColorPickMouseDown(object sender, MouseEventArgs e)
{
Panel pnlSender = (Panel)sender;
currentColor = pnlSender.BackColor;
}
private void panelTarget_MouseMove(object sender, MouseEventArgs e)
{
//the mouse button is released
if (SortMouseLocation == Point.Empty)
{
Panel pnl = (Panel)sender;
pnl.BackColor = currentColor;
}
}
I'm wondering if it's possible to use ToolTip.SetToolTip or something similar to open a control as a tooltip instead of just a string (i.e. SetToolTip(controlToWhichToAdd, panelToDisplayAsToolTip) instead of passing a string as your second parameter).
If this isn't possible I'm guessing next best thing is displaying a panel on the mouse location on mouse_enter event on the control and removing it (or making it invisible) on mouse_leave.
Or are there other practices that make this possible in an easier way?
This is not possible out of the box. You have two choices. First option is to override the Draw Event, which will let you customize how the tooltip looks. Here is an example of this. Be sure you set the OwnerDraw property to true if you use this method!
Although the first method will work if you just need some simple customization, the second option will work best if you need more flexible options. The second option is to do what you already suggested and create your own sort of tooltip. Simply put, you would first create an event handler for the MouseEnter event. When that event fires, you'd enable a Timer. This timer would be the delay that occurs before the tooltip is show. Then finally, you'd just make your panel appear at the mouse coordinates.
Suppose you have a form with a button and timer on it and you want the button to have a tooltip that is a panel:
public partial class Form1 : Form
{
private Panel _myToolTipPanel;
private void Form1_Load(object sender, EventArgs e)
{
_myToolTipPanel = new Panel {Visible = false};
Controls.Add(_myToolTipPanel);
Label myLabel = new Label();
myLabel.Text = "Testing";
_myToolTipPanel.Controls.Add(myLabel);
}
private void button1_MouseEnter(object sender, EventArgs e)
{
timer1.Enabled = true;
}
private void button1_MouseLeave(object sender, EventArgs e)
{
timer1.Enabled = false;
_myToolTipPanel.Visible = false;
}
private void timer1_Tick(object sender, EventArgs e)
{
timer1.Enabled = false;
Point position = Cursor.Position;
Point formPoisition = PointToClient(position);
_myToolTipPanel.Visible = true;
_myToolTipPanel.Location = formPoisition;
}
}
Now of course you will have to do some beautifying of the tooltip, but this is the general idea!
One Approach could be inheriting the ToolTip control and then override the SetToolTip and Show methods . Inside the SetToolTip the private method - SetToolTipInternal needs to be re-written , but most of the functionality could be reuse - it uses the Mouse Events ( leave , move) to bind region. but since tooltip uses internal's of windows to show the baloon window. you will have to override quite a bit of code.
but this could be time consuming and needs quite a bit of testing.
You could write a handler for the Tooltip.Popup event, and cancel the popup to display your own panel.
You'd need to clean it up at the appropriate time, though.
For example:
private void ToolTip1_Popup(Object sender, PopupEventArgs e)
{
e.Cancel = true;
//Do work here to display whatever control you'd like
}
If you're just looking for more formatting options in the tooltip display, an alternative is something like this CodeProject entry, which implements an HTML-enabled tooltip:
I am new to using Event Handling in C# .NET, and I am trying to understand the behavior behind some simple code that I am experimenting with. I am working with a more complicated example, but I am hoping I will get a more focused answer if I simplify the example.
I have the following code which defines a main window with a ListBox that is initialized with values, and a panel in the window. I am working with dragging the ListBox Items and dropping them in the panel. To signify that the panel is reading the DragDrop event, I am simply just changing the background color.
My problem is, it is not changing the background color when I drop the values, hence, the DragDrop is not working. I know this is a bit exaggerated, but I am trying to understand why its not working.
Here is the following code that I am using.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
//Allow Panel to accept dropped values
this.panel1.AllowDrop = true;
//Initialize ListBox with sample values
listBox1.Items.Add("First Name");
listBox1.Items.Add("Last Name");
listBox1.Items.Add("Phone");
//Setup DragDrop Event Handler - is this correct, or even needed?
this.panel1.DragDrop += new DragEventHandler(panel1_DragDrop);
}
private void listBox1_MouseDown(object sender, MouseEventArgs e)
{
ListBox box = (ListBox)sender;
String selectedValue = box.Text;
DoDragDrop(selectedValue.ToString(), DragDropEffects.Copy);
}
private void panel1_DragDrop(object sender, DragEventArgs e)
{
//Change Background color to signify value has been dropped
((Panel)sender).BackColor = Color.Black;
}
}
I realize this is an oversimplified example. If you see what I am doing wrong, then please let me know.
EDIT To give an example of why I am confused, I change this example around to put the dragged ListBox Item text into a Textbox when the DragOver event was fired, and it worked fine, but when I tried to do the same thing when they dropped the values over the textbox, I could not get it to work.
Handle the panel's DragEnter event and set e.Effects to something other than None.