I have a C# .NET WinForm. In the form, I allow a user to add an item to a ListView by double-clicking in the ListView. This adds a TextBox control to the ListView and places the key cursor in the TextBox so a user can type.
I detect that a user is done with an item in a couple of ways (e.g. pressing Enter, Esc, Tab...), but also when they Leave (TextBox.Leave) the TextBox.
The problem is this set of steps:
User triggers TextBox.Leave by mousing down outside of the TextBox.
I add the new item to the ListView.
I select the the new item in the ListView.
Mouse up occurs and the new item that I just selected, loses focus and is unselected.
What I would like is for TextBox.Leave to be triggered by MouseUp, not MouseDown. How can I accomplish this?
Edit: Cody suggests using the ListView.LabelEdit property. Here are my results trying that:
listView_DoubleClick(...) {
listView.LabelEdit = true;
if(double clicked on existing listViewItem) {
listViewItem.BeginEdit(); //this works as expected
} else {
var newItem = listView.Items.Add("");
newItem.BeginEdit(); //this doesn't work, see below
}
}
The call to newItem.BeginEdit() only works when the user double clicks where the new item will show up. If they double click on any other blank area in the listview the new item is added, but it does not enter edit mode. What's going on here?
Pressing the mouse down on another control is causing that other control to request the focus and so the focus moving causes the TextBox.Leave event to occur. Preventing ever other possible control from requesting the focus is not a very viable option. But luckly you only need to prevent the ListView from using the MouseDown to shift focus. So you need to override the WndProc of your ListView and when the MouseDown windows message occurs and you are currently showing a TextBox you eat the message. In order words you do not allow the base class to process it.
Related
I have several TextBoxes within a UniformGrid.
I want to select all the within a textbox when it is clicked I'd rather the event came from the uniformgrid. I was able to implement selecting all the text with GotKeyboardFocus for when I use only the keyboard with the code below in the handler. However when I merely click on the box it highlights while my mouse is down and on mouse up the cursor appears rather than the text remaining selected.
foreach(TextBox Box in grid.Children)
{
if (Box.IsKeyboardFocusWithin)
{
Box.SelectAll();
e.Handled = true;
break;
}
}
I also have an PreviewKeyUp handler that watches for a max number of letters then moves to the next box. Also each box is initialized with the max number of letters when the screen loads. Which is why I want to do a select all on the text in the textbox so it can be typed over easily.
I was able to use GotMouseCapture almost perfectly except that it doesn't work if you click near the text only near the edge of the textbox.
Try hooking up to the PreviewMouseUp routed event. That worked for me.
I have a wondows form which contains a WPF control as well. When I click on the control it brings up a WPF popup control with a listbox. The goal is, when I select an item on the listbox, the windows form will be repopulated accordingly and the popup should get closed. The current implementation with SelectionChanged on the listbox works fine.
Here is the problem. The popup is big and covers some portion of the winform which contains some links. Now, when I select an item on the listbox, the popup closes after doing necessary actions, but if there is a link just below the popup (on the winform) that is under the cursor (when you selected the item on the listbox), that link is also taking the click event.
Is there any way to prevent the links getting clicked when I click on the popup? I have to close the popup though.
I think I figured this out.
SelectionChanged gets executed when we press the mouse key down and before we lift it.(Mouse key up). The popup gets closed in SelectionChanged before we lift the Mouse key. So, when we leave the mouse key, the keyUp event actually gets fired for a link on the Winform as the popup has been closed by now.
I moved the logic from SelectionChanged to PreviewMouseUp and the popup stays till I leave the mouse key and therefore the links on the Winform do not get the event. Of course, I check whether the selection has been changed or not.
My WPF application uses the Telerik RadGridView control on a few of its screens. I have a requirement that says that whenever the user clicks on a row in the RadGridView, I'm supposed to switch to another screen and display detail information about that row. I hooked up a handler to the SelectionChanged event and this works, except that nothing happens if the user clicks on the selected row a second time. This makes sense, as the selected row isn't being changed.
How can I detect a second click on the same row and have the second screen displayed?
Tony
You could just attach a handler to the MouseUp event on the GridView. Check if there are any selected cells and respond from there. This will fire even if there is already a selection.
The MouseDown event will fire on the mouse click, but before the gridview updates the selction, mouse up should fire when the selection has already been adjusted
You can also attach a handler to each individual cell in code-behind as follows
(this.GridView as RadGridView).AddHandler(
GridViewCell.MouseUpEvent,
new EventHandler<Telerik.Windows.RadRoutedEventArgs>(this.OnMouseUp));
I think you may try to achieve this through the MouseLeftButtonDown event or PreviewMouseLeftButtonDown event.
I have some buttons in a bottom toolbar of a gridpanel that control adding, and removing records from the row-editing grid.
The handlers are pretty simple: "new" button creates an instance of the model, appends to the grid and then opens a row-editor on the new row; "edit" button just opens the selected row's row-editor; "remove" destroys the record from the store and refreshes the grid view.
For some reason these buttons don't lose the focus class that gives them a border when they have the focus. Here is a picture:
In the picture both the "New" button and the "Remove" button have the focus class, when I press the "Edit" button it also keeps the focus classes even after doing a complete row-edit operation and closing the row-editor.
I did find that when I mousedown on one of these permanently "focused" buttons and then mouseup away from it and then click something else the focus class goes away.
I know that I could put a blur handler for all button components in my respective controllers but I would have thought that this functionality was built in so I am asking to see if there is something I missed somewhere in the docs.
The classes that it won't let go of are these:
x-focus x-btn-focus x-btn-default-toolbar-small-focus
This is with ExtJS 4.1.0 in FF10 on Windows 7. But I did notice similar behavior in ExtJS 4.02 and 4.07, just haven't needed to handle it until now.
I found out what it was:
At some point in the handler chain for each of these buttons the button gets disabled. When a button is disabled in ExtJS it prevents the blur event from firing.
It was necessary to disable the buttons so the solution to simply add button.blur() in the handler was the correct way to do go about it.
In WPF I have a TreeView control where a particular item can be selected either by the user selecting the item directly in the tree view or by clicking on a screen control. The tree view is displaying a list of elements that are being displayed on a user defined form, basically a form designer application.
Here is my problem. When the user clicks on a screen control it calls a method that returns the TreeViewItem that represents the element. It then sets the IsSelected property to true for this element. It correctly changes the visual indicator in the TreeView and it raised the SelectedItemChanged event in the TreeView. This is all good.
However, it appears that somewhere behind the scenes the TreeView still thinks the previous item is selected. Here is why I have come to this conclusion. If I select ElementA by clicking on it in the TreeView is it correctly selected. If I then select ElementB by clicking on the screen control and programmatically setting the IsSelected property for the ElementB TreeViewItem it appears to have selected it correctly. Now if I select ElementA again by clicking on it in the TreeView it does nothing. The SelectedItemChanged event is not raised and the reverse selection box that indicates the selected item stays on ElementB. If I click on ElementB in the TreeView it also does not raise the SelectedItemChanged event, however it does not appear to update the internal flag since if I then click on ElementA on the TreeView it processes it correctly and raises the event.
The only workaround that I have found for this is in the SelectedItemChanged event handler to call the Focus method for the now selected TreeViewItem. If I do this I get the expected behaviour when I select screen controls and programmatically change the selected TreeViewItem.
This is not an acceptable solution though as it creates focus change flicker. When I select items on my form window the focus goes to the TreeView control and then back to the form, causing flicker and slight delay.
Anyone have any indeas.
Update
As requested here is some code. Here is my method of my Explorer window which is the manager of the TreeView in question.
public bool SelectItemByName(String controlName)
{
bool fReturn = false;
TreeViewItem tviToSelect = FindItemByName(_tviMaster, controlName);
if (tviToSelect != null && _tviSelectedItem != tviToSelect)
{
tviToSelect.IsSelected = true;
// Make sure the selected item is visible in the TreeView by expanding all of the parent nodes
ExpandAllParents(tviToSelect);
tviToSelect.BringIntoView();
fReturn = true;
}
return fReturn;
}
Every element has a unique identifier that I use as a cross reference between different areas of the interface. When you click a screen control it uses its identifier to find the cooresponding TreeViewItem in the TreeView. Then this code sets it as selected.
Then in my SelectedItemChanged event handler I had to include the following line.
_tviSelectedItem.Focus();
This fixes my initial issue but introducing the unwant screen flicker.
To recap, I select ElementA in the TreeView directly, then select one or more other elements in the form designer which in turn calls SelectItemByName to programatically set the selected item. All visual indicators show that this worked. In the TreeView the highlighted item changes to the new item that is selected. After selecting any number of elements through the form designer interface if you select ElementA by clicking on it directly in the TreeView it does nothing. It does not get highlighted and it does not fire the SelectedItemChanged event. If you inspect the SelectedItem and SelectedValue properties of the TreeView they all correctly coorespond to the item that was programmatically selected. However, the control somewhere appears to think that ElementA is still selected and doesn't recognize that the selection is changing.
I cannot believe that other people haven't run into this. It appears to be a significant flaw in the TreeView contol in WPF. Not sure if WinForms has the same issue or not.
Each TreeViewItem has an IsSelected property, and I suspect the old one isn't getting set to false. Try setting it to false whenever you set the new item to true.
var currentItem = treeView.ItemContainerGenerator
.ContainerFromItem(treeView.SelectedItem) as TreeViewItem;
currentItem.IsSelected = false;
If that doesn't work, try setting focus on the newly selected item at the same time as when you select it. Don't forget that WPF also has two focus scopes: Logical Focus and Keyboard Focus. You may need to set both.
treeViewItem.Focus(); // Sets Logical Focus
Keyboard.Focus(treeViewItem); // Sets Keyboard Focus