im looking for an Drag/Drop cancelled event in Metro, this means if the user drags an item and drops it outside of an droppable area.
how can i achieve this or is there any workaround?
I have not found such an event (for c#/XAML)! Perhaps (hopefully) an event will exists in the final release!
As a temporary workaround, I have registered to the Window.Current.CoreWindow.PointerReleased-event.
On drag start then, I set a boolean indicator to true, and if drag ends, the PointerReleased-event will be fired and I can test for the boolean indicator.
Workaround
In the constructor of the Page (or whatever element) register to PointerReleased:
Window.Current.CoreWindow.PointerReleased+=CoreWindow_PointerReleased;
The eventhandler could look somehow like this:
void CoreWindow_PointerReleased(CoreWindow sender, PointerEventArgs args) {
if (m_isDragging) {
m_isDragging = false;
// Here you know that a drag-operation came to a end
}
}
And the indicator you can set for example as follows;
private void Entries_DragStarting(object sender, DragItemsStartingEventArgs e){
m_isDragging = true;
// ...
}
Dude,
instead of capturing pointer released on the whole page
you can register "pointer capture lost" on the listview or the item that you drag, i believe it fires less times at least :D
listView_PointerCaptureLost(object sender, PointerRoutedEventArgs e){
//do the logic you want;
}
Related
I have a TextBox and I want all the text inside of it to be highlighted when the user clicks on it (so that they can replace it easily). I have the following event handler linked up the the TextBox:
private void TextBox_Enter(object sender, EventArgs e) {
SelectAll();
}
When I click on the TextBox, the text is only selected for a fraction of a second (sometime it's so fast I can't see it at all) and then it goes back to being a cursor. Does anyone know how to fix this or if there are any relatively simple workarounds?
I tried the same thing with the TextBox.MouseClick event (and it highlighted the text), but because it was the MouseClick event the text was highlighted every time I clicked the TextBox (even when the TextBox already had focus).
I have also tried SelectionStart = 0; SelectionLength = Text.Length, but the same thing happens. This leads me be believe the issue has something to do with the event.
I also tried the TextBox.GotFocus event and had the exact same problem.
I am doing this in a Windows Form application.
The reason why you didn't see the text getting selected is that the TextBox is busy when one of those events occurred (e.g., caret positioning). You actually select the text, but then the internal event handlers of the TextBox execute and remove the selection e.g. by setting the caret position.
All you have to do is to wait until the internal event handlers have completed.
You do this by using the Dispatcher. When you invoke the Dispatcher asynchronously the delegate is not immediately executed but enqueued and executed once all previously enqueued actions (like the internal event handlers) are cleared from the dispatcher queue.
So going with the TextBox.GotFocus event in WPF (or the TextBox.Enter in WinForms) and the asynchronous Dispatcher will do the trick:
WPF
private async void SelectAll_OnTextBoxGotFocus(object sender, RoutedEventArgs e)
{
await Application.Current.Dispatcher.InvokeAsync((sender as TextBox).SelectAll);
}
WinForms
private void SelectAll_OnTextBoxEnter(object sender, EventArgs e)
{
var textBox = sender as TextBox;
textBox.BeginInvoke(new Action(textBox.SelectAll));
}
Thankfully I found a solution! It turns out that the Click event is executed before the Enter event, this allowed me to set up a JustGotFocus variable and do the following:
private void myTextBox_Click(object sender, EventArgs e) {
this.JustGotFocus = true;
if (JustGotFocus) {
myTextBox.SelectAll();
}
}
private void myTextBox_Enter(object sender, EventArgs e) {
JustGotFocus = false;
}
If anyone else has this problem hopefully my solution is useful.
I am self teaching myself C# and ran into a problem I haven't seem to find an answer too. I have a Form that when I mouse click the check box the state goes to true but also immediately triggers the mouse click event I have code follows:
private void uxCheckBoxMouseClick(object sender, MouseEventArgs e)
{
//MouseEventArgs me = (MouseEventArgs) e;
if (uxMouseCopyCheckBox.Checked)
{
MessageBox.Show("Test");
uxMouseCopyCheckBox.Checked = false;
}
}
I have searched the stack overflow and Google and found similar items but not in C# but no luck on the fixed solution. What I want to do it use the first click to change the check box to true without triggering the mouse click event. I want to delay the event to the 2nd mouse click and not the first.
I have tried the following:
for loop
Clicks == 2 with if statement
subscribing but at a loss on what to use
Instead of the Click event you could subsribe to the CheckedChanged event :
The Handler will look look exactly like yours :
private void uxMouseCopyCheckBox_CheckedChanged(object sender, EventArgs e)
{
if (!uxMouseCopyCheckBox.Checked)
{
MessageBox.Show("Test");
uxMouseCopyCheckBox.Checked = false;
}
}
The only difference is that we want the Message box to be shwon only on the second click so when you will uncheck the checkbox.
Be careful though, if you change the default state of the checkbox, it will no longer work.
If you want a really robust solution Grant's one is IMHO the best, mine was just here to show you how to adapt your code for it to work
Just use a boolean variable as a flag.
private bool wasAlreadyClickedOnce;
private void uxCheckBoxMouseClick(object sender, MouseEventArgs e)
{
if (!wasAlreadyClickedOnce)
{
wasAlreadyClickedOnce = true;
return;
}
if (uxMouseCopyCheckBox.Checked)
{
MessageBox.Show("Test");
uxMouseCopyCheckBox.Checked = false;
}
}
Try using the Click event instead of CheckedChanged event to check or uncheck the CheckBox and then you can use the MouseClick event for other stuff.
I am working on a pretty basic C# visual studio forms application but am having some issue getting the track bar to act as I want it to so hoping someone in the community might have a solution for this.
What I have is a pretty basic application with the main part being a track bar with a value of 0 to 100. The user sets the value of the track to represent "the amount of work to perform" at which point the program reaches out to some devices and tells them to do "x" amount of work (x being the value of the trackbar). So what I do is use the track bars scroll event to catch when the track bars value has changed and inside the handler call out to the devices and tells them how much work to do.
My issue is that my event handler is called for each value between where the track bar currently resides and where ever it ends. So if it is slid from 10 to 30, my event handler is called 20 times which means I am reaching out to my devices and telling them to run at values I don't even want them to run at. Is there someway only to event when scroll has stopped happening so you can check the final value?
Just check a variable, if the user clicked the track bar. If so, delay the output.
bool clicked = false;
trackBar1.Scroll += (s,
e) =>
{
if (clicked)
return;
Console.WriteLine(trackBar1.Value);
};
trackBar1.MouseDown += (s,
e) =>
{
clicked = true;
};
trackBar1.MouseUp += (s,
e) =>
{
if (!clicked)
return;
clicked = false;
Console.WriteLine(trackBar1.Value);
};
For the problem #roken mentioned, you can set LargeChange and SmallChange to 0.
Try the MouseCaptureChanged event - that is the best for this task
A user could also move the track bar multiple times in a short period of time, or click on the track multiple times to increment the thumb over instead of dragging the thumb. All being additional cases where the value that registers at the end of a "thumb move" is not really the final value your user desires.
Sounds like you need a button to confirm the change, which would then capture the current value of the trackbar and send it off to your devices.
Try this with the trackbar_valuechanged event handler:
trackbar_valuechanged(s,e) {
if(trackbar.value == 10){
//Do whatever you want
} else{
//Do nothing or something else
}
}
I found a fairly reliable way to do this is to use a timer hooked up in the trackbar.Scroll event:
private Timer _scrollingTimer = null;
private void trackbar_Scroll(object sender, EventArgs e)
{
if (_scrollingTimer == null)
{
// Will tick every 500ms (change as required)
_scrollingTimer = new Timer()
{
Enabled = false,
Interval = 500,
Tag = (sender as TrackBar).Value
};
_scrollingTimer.Tick += (s, ea) =>
{
// check to see if the value has changed since we last ticked
if (trackBar.Value == (int)_scrollingTimer.Tag)
{
// scrolling has stopped so we are good to go ahead and do stuff
_scrollingTimer.Stop();
// Do Stuff Here . . .
_scrollingTimer.Dispose();
_scrollingTimer = null;
}
else
{
// record the last value seen
_scrollingTimer.Tag = trackBar.Value;
}
};
_scrollingTimer.Start();
}
}
I had this problem just now as I'm implementing a built in video player and would like the user to be able to change the position of the video but I didn't want to overload the video playback API by sending it SetPosition calls for every tick the user passed on the way to his/her final destination.
This is my solution:
First, the arrow keys are a problem. You can try your best to handle the arrow keys via a timer or some other mechanism but I found it more pain than it is worth. So set the property SmallChange and LargeChange to 0 as #Matthias mentioned.
For mouse input, the user is going to have to click down, move it, and let go so handle the MouseDown, MouseUp, and the Scroll events of the trackbar like so:
private bool trackbarMouseDown = false;
private bool trackbarScrolling = false;
private void trackbarCurrentPosition_Scroll(object sender, EventArgs e)
{
trackbarScrolling = true;
}
private void trackbarCurrentPosition_MouseUp(object sender, MouseEventArgs e)
{
if (trackbarMouseDown == true && trackbarScrolling == true)
Playback.SetPosition(trackbarCurrentPosition.Value);
trackbarMouseDown = false;
trackbarScrolling = false;
}
private void trackbarCurrentPosition_MouseDown(object sender, MouseEventArgs e)
{
trackbarMouseDown = true;
}
I had a similar problem, only with a range TrackBar Control. Same idea applies to this also, only it's easier for this case.
I handled the MouseUp Event on the TrackBar to launch the procedures I needed, only after you would let go of the mouse button. This works if you drag the bar to your desired position or just click it.
private void rangeTrackBarControl1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{
YourProcedureHere();
}
i solved the problem for my application with two events:
catch the Trackbar-ValueChange-Event
whithin the value-change event disable the valuechange event and enable the MouseUp-Event
public MainWindow()
{
//Event for new Trackbar-Value
trackbar.ValueChanged += new System.EventHandler(trackbar_ValueChanged);
}
private void trackbar_ValueChanged(object sender, EventArgs e)
{
//enable Trackbar Mouse-ButtonUp-Event
trackbar.MouseUp += ch1_slider_MouseUp;
//disable Trackbar-ValueChange-Event
trackbar.ValueChanged -= ch1_slider_ValueChanged;
}
private void trackbar_MouseUp(object sender, EventArgs e)
{
//enable Trackbar-ValueChange-Event again
trackbar.ValueChanged += new System.EventHandler(trackbar_ValueChanged);
//disable Mouse-ButtonUp-Event
trackbar.MouseUp -= trackbar_MouseUp;
//This is the final trackbar-value
textBox.AppendText(trackbar.Value);
}
ATTENTION: this works if the trackbar is moved by mose. It is also possible to move the trackbar by keyboard. Then futher code must be implemented to handle this event.
I don't know if it is called an argument (i.e. textbox1.text = "Hello";).
I have a control and there is a text box in it. It has a dropdown box that opens when the text is changed. But when I update the text in the text box that box drops down.
I need a way to make it so it only drops down if someone manually does it.
TBAddressBar.ABText.Text = getCurrentBrowser().Source.ToString();
and
public void ABText_TextChanged(object sender, TextChangedEventArgs e)
{
if (sender == 1*)
{
ABDropDown.Visibility = Visibility.Visible;
}
else
{
ABDropDown.Visibility = Visibility.Collapsed;
}
}
If someone manually does it, presumably they are using keypresses to do so. In that case, use KeyDown or KeyUp events to show the dropdown instead.
What I have done in the past is use a boolean variable that I set when I update my textboxes programically to bypass the TextChangedEvent.
i.e.
bool loading;
....
loading =true;
TBAddressBar.ABText.Text = getCurrentBrowser().Source.ToString();
loading = false;
public void ABText_TextChanged(object sender, TextChangedEventArgs e)
{
if(loading) return;
....
}
Simple, just remove the code from your TextChanged Event.
Anyway you got the basic idea.. Now do your dropdown logic in KeyPress event, since it accepts only characters and not the modifiers. So it behaves closer to your requirement. Not that you cant handle the same using KeyDown and KeyUp, you can, but more code..
I'm trying to handle the user changing which items are selected in a listbox (by updating information about what's selected), but if you select a range (using shift+select), it actually fires a separate 'ItemSelectionChanged' event once for EACH item that was selected/deselected, i.e. if you selected 100 items, you get 100 events, and the first time the event handler's called, it seems to have no way of knowing that there's more to come.
Is there a way to not respond until the process of selecting/deselecting items is complete?
There is no SelectedItemsChanged event, I'm guessing you mean SelectedIndexChanged. What you can do is leverage the Control.BeginInvoke() method. The delegate target starts running when the UI thread goes idle again, after all the events have been fired. Make it look like this:
bool listUpdated = false;
private void listView1_SelectedIndexChanged(object sender, EventArgs e) {
if (!listUpdated) {
this.BeginInvoke(new MethodInvoker(updateList));
listUpdated = true;
}
}
private void updateList() {
listUpdated = false;
// etc...
}