I've a text box in that i added a event TextChanged but it doesn't giving me all the data i entered in that text box it neglecting last character but i want all chars what i enter in the text box so how can i do this one please help me.
The TextChanged event gives you all the character:
TextBox currentTextBox = sender as TextBox;
string fullText = CurrentTextBox.Text;
Are you sure your not in like a PreviewKeyDownEvent or any other Preview Events. All of these events neglect the last input
Make an extended TextBox class and handle the KeyUp event to force an update to the text property binding after each key stroke.
public class MyWPFTextBox: TextBox
{
public MyWPFTextBox(): base()
{ KeyUp += new KeyEventHandler(MyWPFTextBox_KeyUp); }
private void MyWPFTextBox_KeyUp(object sender, System.Windows.Input.KeyEventArgs e)
{
BindingExpression BE = GetBindingExpression(TextBox.TextProperty);
if (BE != null)
BE.UpdateSource();
}
}
you should look at the PreviewTextInput event.
you also should take a look at mvvm pattern, binding and UpdateSourceTrigger=PropertyChanged. there you do not need events at all, you get your information via binding.
Related
I have textbox. Its updatesourcetrigger property is set to lostfocus. I dont want to set it to proportychanged.
Now lets say, my WPF form is already dirty and user is updating the textbox. Now user directly press CTRL + S key(i.e. it invokes SAVE command) when focus is in textbox only.
Now updated textbox value is not reflected in viewmodel when save command is invoked.(i.e. my view and viewmodel data is not synchronized.)
Can I somehow pull data from view to viewmodel before command invokes or can I call textbox lostfocus event before invoking command.
Thanks in advance....
Bind Key/Gesture directly on your TextBox and do lost focus. Then let the gesture traverse up to Window to do the save. :)
You need to call UpdateSource on the BindingExpression of the TextBox, but your viewModel does not have access to the TextBox. so you'll need an event in your viewModel to do it.
Write this code in your view:
myViewModel.UpdateTextSource += () =>
{
BindingExpression be = textBox1.GetBindingExpression(MainWindow.TextProperty);
be.UpdateSource();
};
And fire this event inside the command.
if(UpdateTextSource != null)
UpdateTextSource();
If you need to update different textBoxes then you can add a parameter to the event:
if(UpdateTextSource != null)
UpdateTextSource(TextProperty.Name);
And in the view set the tag of all text boxes which have this feature to the name of the property.
<TextBox Text="{Binding PhoneNO}" Tag="PhoneNO"/>
Then get the parameter to find the text box which has the same tag as the parameter's value.
myViewModel.UpdateTextSource += t =>
{
var tb = GetTextBoxWithTag(t);//implement this function
BindingExpression be = tb.GetBindingExpression(MainWindow.TextProperty);
be.UpdateSource();
};
You can use PreviewKeyDown handler on the relevant System.Windows.IInputElement. In your case, that would be the Wpf control that implements the CTRL+S.
In the handler, check for CTRL+S key press, and if so, "pull" your UIData into the viewmodel.
Thank you all for your valuable input.
I have resolved the problem using MoveFocus method.
In my view, before executing the command I have invoked below function:
private void MoveFocus()
{
var focusElement = KeyBoard.FocusElement as UIElement;
if(focusElement != null)
{
focusElement.MoveFocus(FocusNavigationDirection.Next);
}
}
So before my command gets executed, textbox will lose the focus and entered textbox value will be reflected in viewmodel.....:):)
I answer for similar question in https://stackoverflow.com/a/47309346/4554937. I write command which update binding source for focused keyboard element and execute it before save data.
Piece of my CommitValueCommand
public void Execute(object parameter)
{
if (Keyboard.FocusedElement is TextBox textBox)
{
BindingOperations.GetBindingExpression(textBox, TextBox.TextProperty).UpdateSource();
}
}
I have made a textbox and I want the user to type in a string of numbers and hit enter. I have setup the following:
private void textBox1_TextChanged(object sender, EventArgs e)
{
String UserBarcode;
Focus();
UserBarcode = Console.ReadLine();
MessageBox.Show(UserBarcode);
}
When I enter any key into the textbox, I get a message box with nothing in it. I want to have the program wait til it hears the enter key then display the contents of the textbox.
The Textbox.TextChanged event fires as soon as the text in the textbox is changed at all. If you want a message box with the full string, you probably want to consider using the Textbox.LostFocus event or a button's Click event.
So you could have something like (I'm taking a stab at this here, as I've used VB rather than C#)
private void textBox1_LostFocus(object sender, EventArgs e)
{
MessageBox.Show(sender.Text)
}
If you're using a button, the above function should work, but you'll want to substitute textBox1.Text for sender.Text.
Take a look at Focus and Validation Events
There are several events that you can handle, depending on your goals and how your application is designed. If you want to perform validation and/or are using data binding, you may want to go with handling the validating/validated events. By default data bindings update a bound property after OnValidating. If you use LostFocus and read the value from a bound object, instead of your control, you will get inconsistent results.
I was able to figure it out finally. For some reason when I manually entered the code I kept getting multiple random errors. I started a new Visual C # Windows Forms Application, Made a textbox, chose the keydown property and double clicked on it to have the program inject the code for the keydown function and then I filled in the if statement pointing to the enter key. The final code looks like this:
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
MessageBox.Show(textBox1.Text);
}
}
I need to get the text changed event of tooltip. But I cant see any event like this.
How can I get this event or events which enable me to get this event?
Any help will be greately appreciated.
İbrahim
You would usually bind the value of your ToolTip to a property of your view model.
However if you really require an event, you would do this:
SomeMethod()
{
...
var descriptor = DependencyPropertyDescriptor.FromProperty(
ToolTipService.ToolTipProperty, typeof (UIElement));
// we're interested in a TextBox called textBox
descriptor.AddValueChanged(textBox, TooltipChanged);
...
textBox.ToolTip = "Hello";
}
private void TooltipChanged(object sender, EventArgs eventArgs)
{
// output's "Hello"
Debug.WriteLine(textBox.ToolTip);
}
I have combobox in WPF application that when the user clicks on it, it selects all the text. How can I change the behavior of this to when the user clicks it just set the typing cursor like a normal textbox?
Try
<ComboBox IsEditable="True" />
According to Reflector, the ComboBox code contains this:
private static void OnGotFocus(object sender, RoutedEventArgs e)
{
ComboBox box = (ComboBox) sender;
if ((!e.Handled && box.IsEditable) && (box.EditableTextBoxSite != null))
{
if (e.OriginalSource == box)
{
box.EditableTextBoxSite.Focus();
e.Handled = true;
}
else if (e.OriginalSource == box.EditableTextBoxSite)
{
box.EditableTextBoxSite.SelectAll(); // <==
}
}
}
This method is registered for the GotFocus event in the static constructor using the EventManager:
EventManager.RegisterClassHandler(typeof(ComboBox), UIElement.GotFocusEvent, new RoutedEventHandler(ComboBox.OnGotFocus));
So, I think you can only change that behavior by deriving a custom control from ComboBox and override this event registration by your own method which replaces the call to SelectAll() with another method which sets the caret to the correct position. However, I do not know how to set the caret to the click position. You might have to use Reflector on the TextBox to find that...
Seems that I had to solve similar issue.
It's quite tricky, but the way I solved is to set IsEditable to false/true from code, at the same time I set the focus on TextBox.
Not the pretties way but does the job.
So basically, I have a bunch of TextBoxes that the user gets to fill out. I've got a button that I want to keep disabled until all the TextBoxes have had text entered in them. Here is a sample XAML TextBox that I'm using:
<TextBox Name="DelayedRecallScore" TextInput="CheckTextBoxFilled" Width="24" />
And here is the function that I'm trying to trigger:
//Disables the OK button until all score textboxes have content
private void CheckTextBoxFilled(object sender, RoutedEventArgs e)
{
/*
foreach (TextBox scorebox in TextBoxList)
{
if (string.IsNullOrEmpty(scorebox.Text))
{
Ok_Button.IsEnabled = false;
return;
}
}
Ok_Button.IsEnabled = true;
*/
MessageBox.Show("THIS MAKES NO SENSE");
}
The MessageBox is not showing up when TextInput should be getting triggered. As an experiment I tried triggering CheckTextBoxFilled() on PreviewTextInput, and it worked fine then, meaning that for whatever reason, the function just isn't getting called. I also have a validation function that is triggered by PreviewTextInput, which works as it should. At first I thought PreviewTextInput might somehow be interfering with TextInput, so I took PreviewTextInput off the TextBox, but that hasn't managed to fix anything. I'm completely befuddled by why this might happen, so any help would be appreciated.
Your handler for the TextInput event is not fired because the TextBox is handling the event. You could try using the TextChanged event instead, since really you just want to know when characters were added or removed from the TextBox.
InitializeComponent();
textbox.AddHandler(TextBox.TextInputEvent,
new TextCompositionEventHandler(TextBox_TextInput_1),
true);
Use "PreviewTextInput" instead, it will work.
Create a new class derived from TextBox. In the new class override the OnTextInput method. Your OnTextInput method will get called before the TextBox gets it.