How can I make a transparent tabPage? I found solutions like set both Form's BackColor and TransparencyKey to a color like Color.LimeGreen or override OnPaintBackground with a empty method but TabPage doesn't have neither TransparencyKeyproperty norOnPaintBackground` method. How can I do that?
TabControl is a native Windows component, it always draws the tab pages opaque with no built-in support for transparency. Solving this requires a little helping of out-of-the-box thinking, a tab control with transparent tab pages simply devolves to just the tabstrip being visible. All you have to do is use panels to host the controls that are now on the tab pages and make the correct one visible with the SelectedIndexChanged event.
Best to stick this in a derived class so you can still use the tab control normally at design time. Add a new class to your project and paste the code shown below. Compile. Drop the new control from the top of the toolbox onto the form, replacing the existing one.
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
class TransparentTabControl : TabControl {
private List<Panel> pages = new List<Panel>();
public void MakeTransparent() {
if (TabCount == 0) throw new InvalidOperationException();
var height = GetTabRect(0).Bottom;
// Move controls to panels
for (int tab = 0; tab < TabCount; ++tab) {
var page = new Panel {
Left = this.Left, Top = this.Top + height,
Width = this.Width, Height = this.Height - height,
BackColor = Color.Transparent,
Visible = tab == this.SelectedIndex
};
for (int ix = TabPages[tab].Controls.Count - 1; ix >= 0; --ix) {
TabPages[tab].Controls[ix].Parent = page;
}
pages.Add(page);
this.Parent.Controls.Add(page);
}
this.Height = height /* + 1 */;
}
protected override void OnSelectedIndexChanged(EventArgs e) {
base.OnSelectedIndexChanged(e);
for (int tab = 0; tab < pages.Count; ++tab) {
pages[tab].Visible = tab == SelectedIndex;
}
}
protected override void Dispose(bool disposing) {
if (disposing) foreach (var page in pages) page.Dispose();
base.Dispose(disposing);
}
}
Call the MakeTransparent() method in the form's Load event handler:
private void Form1_Load(object sender, EventArgs e) {
transparentTabControl1.MakeTransparent();
}
I have a winforms app and want to trigger some code when a checkbox embedded in a DataGridView control is checked / unchecked. Every event I have tried either
Triggers as soon as the CheckBox is clicked but before its checked state changes, or
Triggers only once the CheckBox looses its focus
I can't seem to find event that triggers immediately after the checked state changes.
Edit:
What I am trying to achieve is that when the checked state of a CheckBox in one DataGridView changes, the data in two other DataGridViews changes. Yet all the events I have used, the data in the other grids only changes after the CheckBox in the first DataGridView looses focus.
To handle the DatGridViews CheckedChanged event you must first get the CellContentClick to fire (which does not have the CheckBoxes current state!) then call CommitEdit. This will in turn fire the CellValueChanged event which you can use to do your work. This is an oversight by Microsoft. Do some thing like the following...
private void dataGridViewSites_CellContentClick(object sender,
DataGridViewCellEventArgs e)
{
dataGridViewSites.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
/// <summary>
/// Works with the above.
/// </summary>
private void dataGridViewSites_CellValueChanged(object sender,
DataGridViewCellEventArgs e)
{
UpdateDataGridViewSite();
}
P.S. Check this article https://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.currentcelldirtystatechanged(v=vs.110).aspx
I found #Killercam's solution to work but was a bit dodgy if the user double clicked too fast. Not sure if other's found that the case either. I found a another solution here.
It uses the datagrid's CellValueChanged and CellMouseUp. Changhong explains that
"The reason for that is OnCellvalueChanged event won’t fire until the DataGridView thinks you have completed editing. This makes senses for a TextBox Column, as OnCellvalueChanged wouldn’t [bother] to fire for each key strike, but it doesn’t [make sense] for a CheckBox."
Here it is in action from his example:
private void myDataGrid_OnCellValueChanged(object sender, DataGridViewCellEventArgs e)
{
if (e.ColumnIndex == myCheckBoxColumn.Index && e.RowIndex != -1)
{
// Handle checkbox state change here
}
}
And the code to tell the checkbox it is done editing when it is clicked, instead of waiting till the user leaves the field:
private void myDataGrid_OnCellMouseUp(object sender,DataGridViewCellMouseEventArgs e)
{
// End of edition on each click on column of checkbox
if (e.ColumnIndex == myCheckBoxColumn.Index && e.RowIndex != -1)
{
myDataGrid.EndEdit();
}
}
Edit: A DoubleClick event is treated separate from a MouseUp event. If a DoubleClick event is detected, the application will ignore the first MouseUp event entirely. This logic needs to be added to the CellDoubleClick event in addition to the MouseUp event:
private void myDataGrid_OnCellDoubleClick(object sender,DataGridViewCellEventArgs e)
{
// End of edition on each click on column of checkbox
if (e.ColumnIndex == myCheckBoxColumn.Index && e.RowIndex != -1)
{
myDataGrid.EndEdit();
}
}
jsturtevants's solution worked great. However, I opted to do the processing in the EndEdit event. I prefer this approach (in my application) because, unlike the CellValueChanged event, the EndEdit event does not fire while you are populating the grid.
Here is my code (part of which is stolen from jsturtevant:
private void gridCategories_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
if (e.ColumnIndex == gridCategories.Columns["AddCategory"].Index)
{
//do some stuff
}
}
private void gridCategories_CellMouseUp(object sender, DataGridViewCellMouseEventArgs e)
{
if (e.ColumnIndex == gridCategories.Columns["AddCategory"].Index)
{
gridCategories.EndEdit();
}
}
Here is some code:
private void dgvStandingOrder_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
if (dgvStandingOrder.Columns[e.ColumnIndex].Name == "IsSelected" && dgvStandingOrder.CurrentCell is DataGridViewCheckBoxCell)
{
bool isChecked = (bool)dgvStandingOrder[e.ColumnIndex, e.RowIndex].EditedFormattedValue;
if (isChecked == false)
{
dgvStandingOrder.Rows[e.RowIndex].Cells["Status"].Value = "";
}
dgvStandingOrder.EndEdit();
}
}
private void dgvStandingOrder_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
dgvStandingOrder.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
private void dgvStandingOrder_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
if (dgvStandingOrder.CurrentCell is DataGridViewCheckBoxCell)
{
dgvStandingOrder.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
}
following Killercam'answer, My code
private void dgvProducts_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
dgvProducts.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
and :
private void dgvProducts_CellValueChanged(object sender, DataGridViewCellEventArgs e)
{
if (dgvProducts.DataSource != null)
{
if (dgvProducts.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString() == "True")
{
//do something
}
else
{
//do something
}
}
}
This also handles the keyboard activation.
private void dgvApps_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
if(dgvApps.CurrentCell.GetType() == typeof(DataGridViewCheckBoxCell))
{
if (dgvApps.CurrentCell.IsInEditMode)
{
if (dgvApps.IsCurrentCellDirty)
{
dgvApps.EndEdit();
}
}
}
}
private void dgvApps_CellValueChanged(object sender, DataGridViewCellEventArgs e)
{
// handle value changed.....
}
Ben Voigt found the best solution in a comment-reply above:
private void dgvStandingOrder_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
if (dgvStandingOrder.CurrentCell is DataGridViewCheckBoxCell)
dgvStandingOrder.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
Seriously, that's ALL you need.
What worked for me was CurrentCellDirtyStateChanged in combination with datagridView1.EndEdit()
private void dataGridView1_CurrentCellDirtyStateChanged( object sender, EventArgs e ) {
if ( dataGridView1.CurrentCell is DataGridViewCheckBoxCell ) {
DataGridViewCheckBoxCell cb = (DataGridViewCheckBoxCell)dataGridView1.CurrentCell;
if ( (byte)cb.Value == 1 ) {
dataGridView1.CurrentRow.Cells["time_loadedCol"].Value = DateTime.Now.ToString();
}
}
dataGridView1.EndEdit();
}
It's all about editing the cell, the problem that is the cell didn't edited actually, so you need to save The changes of the cell or the row to get the event when you click the check box so you can use this function:
datagridview.CommitEdit(DataGridViewDataErrorContexts.CurrentCellChange)
with this you can use it even with a different event.
I have found a simpler answer to this problem. I simply use reverse logic. The code is in VB but it is not much different than C#.
Private Sub DataGridView1_CellContentClick(sender As Object, e As
DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
Dim _ColumnIndex As Integer = e.ColumnIndex
Dim _RowIndex As Integer = e.RowIndex
'Uses reverse logic for current cell because checkbox checked occures
'after click
'If you know current state is False then logic dictates that a click
'event will set it true
'With these 2 check boxes only one can be true while both can be off
If DataGridView1.Rows(_RowIndex).Cells("Column2").Value = False And
DataGridView1.Rows(_RowIndex).Cells("Column3").Value = True Then
DataGridView1.Rows(_RowIndex).Cells("Column3").Value = False
End If
If DataGridView1.Rows(_RowIndex).Cells("Column3").Value = False And
DataGridView1.Rows(_RowIndex).Cells("Column2").Value = True Then
DataGridView1.Rows(_RowIndex).Cells("Column2").Value = False
End If
End Sub
One of the best things about this is no need for multiple events.
I've tried some answers from here, but I've always had some kind of problem (like double clicking or using the keyboard). So, I combined some of them and got a consistent behavior (it's not perfect, but works properly).
void gridView_CellContentClick(object sender, DataGridViewCellEventArgs e) {
if(gridView.CurrentCell.GetType() != typeof(DataGridViewCheckBoxCell))
return;
if(!gridView.CurrentCell.IsInEditMode)
return;
if(!gridView.IsCurrentCellDirty)
return;
gridView.EndEdit();
}
void gridView_CellMouseUp(object sender, DataGridViewCellMouseEventArgs e) {
if(e.ColumnIndex == gridView.Columns["cFlag"].Index && e.RowIndex >= 0)
gridView.EndEdit();
}
void gridView_CellValueChanged(object sender, DataGridViewCellEventArgs e) {
if(e.ColumnIndex != gridView.Columns["cFlag"].Index || e.RowIndex < 0)
return;
// Do your stuff here.
}
The Code will loop in DataGridView and Will check if CheckBox Column is Checked
private void dgv1_CellMouseUp(object sender, DataGridViewCellMouseEventArgs e)
{
if (e.ColumnIndex == 0 && e.RowIndex > -1)
{
dgv1.CommitEdit(DataGridViewDataErrorContexts.Commit);
var i = 0;
foreach (DataGridViewRow row in dgv1.Rows)
{
if (Convert.ToBoolean(row.Cells[0].Value))
{
i++;
}
}
//Enable Button1 if Checkbox is Checked
if (i > 0)
{
Button1.Enabled = true;
}
else
{
Button1.Enabled = false;
}
}
}
In the event CellContentClick you can use this strategy:
private void myDataGrid_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
if (e.ColumnIndex == 2)//set your checkbox column index instead of 2
{ //When you check
if (Convert.ToBoolean(myDataGrid.Rows[e.RowIndex].Cells[2].EditedFormattedValue) == true)
{
//EXAMPLE OF OTHER CODE
myDataGrid.Rows[e.RowIndex].Cells[5].Value = DateTime.Now.ToShortDateString();
//SET BY CODE THE CHECK BOX
myDataGrid.Rows[e.RowIndex].Cells[2].Value = 1;
}
else //When you decheck
{
myDataGrid.Rows[e.RowIndex].Cells[5].Value = String.Empty;
//SET BY CODE THE CHECK BOX
myDataGrid.Rows[e.RowIndex].Cells[2].Value = 0;
}
}
}
The best way that I found (which also doesn't use multiple events) is by handling the CurrentCellDirtyStateChanged event.
private void dataGrid_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
if (dataGridMatten.CurrentCell.OwningColumn == dataGridMatten.Columns["checkBoxColumn"] && dataGridMatten.IsCurrentCellDirty)
{
dataGrid.CommitEdit(DataGridViewDataErrorContexts.Commit);
//your code goes here
}
}
To do this when using the devexpress xtragrid, it is necessary to handle the EditValueChanged event of a corresponding repository item as described here. It is also important to call the gridView1.PostEditor() method to ensure the changed value has been posted. Here is an implementation:
private void RepositoryItemCheckEdit1_EditValueChanged(object sender, System.EventArgs e)
{
gridView3.PostEditor();
var isNoneOfTheAboveChecked = false;
for (int i = 0; i < gridView3.DataRowCount; i++)
{
if ((bool) (gridView3.GetRowCellValue(i, "NoneOfTheAbove")) && (bool) (gridView3.GetRowCellValue(i, "Answer")))
{
isNoneOfTheAboveChecked = true;
break;
}
}
if (isNoneOfTheAboveChecked)
{
for (int i = 0; i < gridView3.DataRowCount; i++)
{
if (!((bool)(gridView3.GetRowCellValue(i, "NoneOfTheAbove"))))
{
gridView3.SetRowCellValue(i, "Answer", false);
}
}
}
}
Note that because the xtragrid doesnt provide an enumerator it is necessary to use a for loop to iterate over rows.
Removing the focus after the cell value changes allow the values to update in the DataGridView. Remove the focus by setting the CurrentCell to null.
private void DataGridView1OnCellValueChanged(object sender, DataGridViewCellEventArgs dataGridViewCellEventArgs)
{
// Remove focus
dataGridView1.CurrentCell = null;
// Put in updates
Update();
}
private void DataGridView1OnCurrentCellDirtyStateChanged(object sender, EventArgs eventArgs)
{
if (dataGridView1.IsCurrentCellDirty)
{
dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit);
}
}
You can force the cell to commit the value as soon as you click the checkbox and then catch the CellValueChanged event. The CurrentCellDirtyStateChanged fires as soon as you click the checkbox.
The following code works for me:
private void grid_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
SendKeys.Send("{tab}");
}
You can then insert your code in the CellValueChanged event.
I use DataGridView with VirtualMode=true and only this option worked for me
(when both the mouse and the space bar are working, including repeated space clicks):
private void doublesGridView_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
var data_grid = (DataGridView)sender;
if (data_grid.CurrentCell.IsInEditMode && data_grid.IsCurrentCellDirty) {
data_grid.EndEdit();
}
}
private void doublesGridView_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
if (e.ColumnIndex == CHECKED_COLUMN_NUM && e.RowIndex >= 0 && e.RowIndex < view_objects.Count) { // view_objects - pseudocode
view_objects[e.RowIndex].marked = !view_objects[e.RowIndex].marked; // Invert the state of the displayed object
}
}
this worked for me
private void employeeDataGridView_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
if (e.ColumnIndex == employeeDataGridView.Columns["employeeStatusColumn"].Index)
{
bool isChecked = (bool)employeeDataGridView.CurrentCell.Value;
if (isChecked)
{
MessageBox.Show("Checked " + isChecked); //out true;
}
else
{
MessageBox.Show("unChecked " + isChecked);
}
}
}
private void employeeDataGridView_CellMouseUp(object sender, DataGridViewCellMouseEventArgs e)
{
if (employeeDataGridView.DataSource != null)
{
if (e.ColumnIndex == employeeDataGridView.Columns["employeeStatusColumn"].Index && e.RowIndex != -1)
{
employeeDataGridView.EndEdit();
}
}
}
private void dataGridViewPendingBill_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
bool isChecked = (bool) dataGridViewPendingBill[e.ColumnIndex, e.RowIndex].EditedFormattedValue;
if (isChecked)
{
totalAmount += int.Parse(dataGridViewPendingBill.Rows[e.RowIndex].Cells["Amount"].Value.ToString());
textBoxAmount.Text = totalAmount.ToString();
}
else
{
totalAmount -= int.Parse(dataGridViewPendingBill.Rows[e.RowIndex].Cells["Amount"].Value.ToString());
textBoxAmount.Text = totalAmount.ToString();
}
dataGridViewPendingBill.EndEdit();
}
I'm new in Xamarin and i'm trying to create a simple page with some components.
One of these component is a Switch it works fine by itself but i would like to change the basic text "inactive/active" by "male/female"
I've seen that in Xaml for windows phone there is a ToggleSwitch Component with a On/OffContent property but i can't seems to find an equivalent in XAML for Xamarin Forms
any idea ?
Thank you!
The lack of built in switch options, or at least the lack of being able to rename the switch options, has been asked a few times.
You could go with custom renders, modify the text at the OS level or do like I chose to do, just build your own switch.
This switch is two buttons laid out horizontally with the text Yes and No. The selected button gets a red border, and the unselected a transparent border.
class CustomSwitch : Grid
{
public event EventHandler<SelectedItemChangedEventArgs> ItemSelected;
private Button negative;
private Button positive;
public static readonly BindableProperty SelectedItemProperty = BindableProperty.Create<CustomSwitch, Object>(t => t.SelectedItem, null, BindingMode.TwoWay, propertyChanged: OnSelectedItemChanged);
public CustomSwitch()
{
try
{
this.HorizontalOptions = LayoutOptions.Center;
this.VerticalOptions = LayoutOptions.Center;
negative = new Button();
negative.Text = "No";
negative.Style = <YourNameSpace>.AppStyling.Style_Button_Switch;
negative.Clicked += (o,s) => OnSelectedItemChanged(this, ItemSelected, (int)Classes.Collections.Enums.SelectionStatus.False);
positive = new Button();
positive.Text = "Yes";
positive.Style = <YourNameSpace>.AppStyling.Style_Button_Switch;
positive.Clicked += (o, s) => OnSelectedItemChanged(this, ItemSelected, (int)Classes.Collections.Enums.SelectionStatus.True);
this.Children.Add(negative, 0,0);
this.Children.Add(positive, 1,0);
}
catch(System.Exception ex)
{
<YourNameSpace>.Classes.Helpers.Helper_ErrorHandling.SendErrorToServer(ex, this.GetType().Name, System.Reflection.MethodBase.GetCurrentMethod().Name);
}
}
public Object SelectedItem
{
get
{
return base.GetValue(SelectedItemProperty);
}
set
{
if (SelectedItem != value)
{
base.SetValue(SelectedItemProperty, value);
InternalUpdateSelected();
}
}
}
private void InternalUpdateSelected()
{
if((int)SelectedItem == (int)Classes.Collections.Enums.SelectionStatus.False)
{
negative.BorderColor = <YourNameSpace>.AppStyling.Color_Selected;
positive.BorderColor = <YourNameSpace>.AppStyling.Color_UnSelected;
positive.Opacity = <YourNameSpace>.AppStyling.Opaque_High;
}
else if ((int)SelectedItem == (int)Classes.Collections.Enums.SelectionStatus.True)
{
negative.BorderColor = <YourNameSpace>.AppStyling.Color_UnSelected;
negative.Opacity = <YourNameSpace>.AppStyling.Opaque_High;
positive.BorderColor = <YourNameSpace>.AppStyling.Color_Selected;
}
else
{
negative.BorderColor = <YourNameSpace>.AppStyling.Color_UnSelected;
negative.Opacity = <YourNameSpace>.AppStyling.Opaque_High;
positive.BorderColor = <YourNameSpace>.AppStyling.Color_UnSelected;
positive.Opacity = <YourNameSpace>.AppStyling.Opaque_High;
}
}
private static void OnSelectedItemChanged(BindableObject bindable, object oldValue, object newValue)
{
CustomSwitch boundSwitch = (CustomSwitch)bindable;
if((int)newValue != (int)Classes.Collections.Enums.SelectionStatus.Unselected)
{
boundSwitch.SelectedItem = (int)newValue == (int)Classes.Collections.Enums.SelectionStatus.False ? (int)Classes.Collections.Enums.SelectionStatus.False : (int)Classes.Collections.Enums.SelectionStatus.True;
}
if (boundSwitch.ItemSelected != null)
{
boundSwitch.ItemSelected(boundSwitch, new SelectedItemChangedEventArgs(newValue));
}
boundSwitch.InternalUpdateSelected();
}
}
In XAML and WinRT, Is there a way to set up a textbox so that it is disabled for text input until it is tapped.
I tried setting up the Tapped event and then setting the IsEnabled=true, but that only seems to work if the IsEnabled=true in the first place.
I found this on MSDN:
http://social.msdn.microsoft.com/Forums/en-US/winappswithcsharp/thread/708c0949-8b06-40ec-85fd-201139ca8b2d
Talks about adding the TappedEvent manually to the event handled for each TextBox, which is cumbersome, but also doesn't seem to work unless IsEnabled was already set to true.
Basically, I want a form where all textboxes display data but are disabled unless the user taps to enable the box and then type.
You can use IsReadOnly instead of IsEnabled to achieve what you are looking for. In addition, you can set up the tapped event handlers in code easily. I'm not sure if setting up handlers in code is a requirement for this to work, as you noted above; however, it does simplify things.
Here are the details.
In the constructor of your page class (here it is MainPage), call the setup function:
public MainPage()
{
this.InitializeComponent();
// call the setup for the textboxes
SetupTextBoxes();
}
Here is where we do the magic - make all textboxes on this page readonly and set up tap handler:
private void SetupTextBoxes()
{
var tbs = GetVisualChildren<TextBox>(this, true);
foreach (var tb in tbs)
{
tb.IsReadOnly = true;
tb.AddHandler(TappedEvent, new TappedEventHandler(tb_Tapped), true);
}
}
Utility function to get a list of all children of the given type (T) of the passed in parent.
private List<T> GetVisualChildren<T>(DependencyObject parent, bool recurse = true)
where T : DependencyObject
{
var children = new List<T>();
int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < numVisuals; i++)
{
DependencyObject v = (DependencyObject)VisualTreeHelper.GetChild(parent, i);
var child = v as T;
if (child == null && recurse)
{
var myChildren = GetVisualChildren<T>(v, recurse);
children.AddRange(myChildren);
}
if (child != null)
children.Add(child);
}
return children;
}
Finally, the event handler. This enables each textbox when tapped.
private void tb_Tapped(object sender, TappedRoutedEventArgs e)
{
((TextBox)(sender)).IsReadOnly = false;
}
In XAML I have the <Slider />. It has the ValueChanged event. This event fires with every change to Value. I need to detect when the value change is over. LostFocus, PointerReleased are not the correct event. How can I detect this?
XAML, WinRT, Windows8.1 and UWP:
PointerCaptureLost event should work for mouse / touch
KeyUp event for keyboard
You can create a new class and inherit from Slider. From there on, you can look for the Thumb control & listen for the events you want.
Something like this should work:
public class SliderValueChangeCompletedEventArgs : RoutedEventArgs
{
private readonly double _value;
public double Value { get { return _value; } }
public SliderValueChangeCompletedEventArgs(double value)
{
_value = value;
}
}
public delegate void SlideValueChangeCompletedEventHandler(object sender, SliderValueChangeCompletedEventArgs args);
public class ExtendedSlider : Slider
{
public event SlideValueChangeCompletedEventHandler ValueChangeCompleted;
private bool _dragging = false;
protected void OnValueChangeCompleted(double value)
{
if (ValueChangeCompleted != null)
{
ValueChangeCompleted(this, new SliderValueChangeCompletedEventArgs(value) );
}
}
protected override void OnApplyTemplate()
{
base.OnApplyTemplate();
var thumb = base.GetTemplateChild("HorizontalThumb") as Thumb;
if (thumb != null)
{
thumb.DragStarted += ThumbOnDragStarted;
thumb.DragCompleted += ThumbOnDragCompleted;
}
thumb = base.GetTemplateChild("VerticalThumb") as Thumb;
if (thumb != null)
{
thumb.DragStarted += ThumbOnDragStarted;
thumb.DragCompleted += ThumbOnDragCompleted;
}
}
private void ThumbOnDragCompleted(object sender, DragCompletedEventArgs e)
{
_dragging = false;
OnValueChangeCompleted(this.Value);
}
private void ThumbOnDragStarted(object sender, DragStartedEventArgs e)
{
_dragging = true;
}
protected override void OnValueChanged(double oldValue, double newValue)
{
base.OnValueChanged(oldValue, newValue);
if (!_dragging)
{
OnValueChangeCompleted(newValue);
}
}
}
You can use pair of bool values isValueChanged and (if possible change value without manipulation of pointer
) isPressed;
private void Slider_ValueChanged(object s, RangeBaseValueChangedEventArgs e) {
if (!isPressed) {
AcceptChanges();
} else {
isValueChanged = true;
}
}
Initialization code:
Window.Current.CoreWindow.PointerPressed += (e, a) => { isPressed = true; };
Window.Current.CoreWindow.PointerReleased += (e, a) => {
isPressed = false;
if (isValueChanged) AcceptChanges();
};
I had a similar issue using a Slider on Windows8/WinRT.
My problem was the following: I was reacting to the ValueChanged Event and performing a long lasting operation (writing asynchronously to a file) after each trigger. And thus running into a concurrent editing exception. In order to avoid this, I used a DispatcherTimer.
//Class member
private DispatcherTimer myDispatcherTimer = null;
private void OnSliderValueChanged(object sender, RangeBaseValueChangedEventArgs e)
{
//I update my UI right away
...
//If the dispatcher is already created, stop it
if (myDispatcherTimer!= null)
myDispatcherTimer.Stop();
//Overwrite the DispatcherTimer and thus reset the countdown
myDispatcherTimer= new DispatcherTimer();
myDispatcherTimer.Tick += (sender, o) => DoSomethingAsync();
myDispatcherTimer.Interval = new TimeSpan(0,0,2);
myDispatcherTimer.Start();
}
private async void DoSomethingAsync()
{
await DoThatLongSaveOperation();
}
You cannot directly detect what the final value is, but you can at least delay the operation until there is a long pause between two updates (e.g. in my case, if the user drags the slider and stops while maintaining the drag for 2 seconds, the save operation will be fired anyway).