I want to make a text box where text can be dragged/dropped into but where the user cannot write text into themselves.
The pseudo code would be as follows:
private void textBox1_TextChanged(object sender, EventArgs e)
{
if( text is not dropped )
{
txtInstructionReg.Text = "";
}
}
I don't believe that you can use events in exactly the way that you're looking to. Instead, I'd suggest handling each event separately to allow/disallow the actions that you wish to control.
For instance, with your example I would have handlers for both of the events that could happen for the textbox. The event that handles typed text would delete the new input and perhaps display a message to the user that effectively says "You can't do that". Then have the drag/drop handler accept text and put it in the textbox.
Related
I'm just curious if there is an easy way to have my text box auto populate a string depending on whether a radio button is clicked.
For example, I have three radio buttons: residential, commercial, industrial
and I have a text box called txtCustomerType
I'm using the input from txtCustomerType to log the info to a list, but right now the user has to manually add R,C or I. The radio buttons are being used for the charge calculation (it's a little program that has different rates depending on customer)
You can use event handlers for this.
Under properties for the item you want, you'll find event handlers here:
Then just double click the event you want, and all the necessary stuff will be automatically created for you.
And here is where you want to write the code what happens when e.g. the checked status changes:
private void radioButton1_CheckedChanged(object sender, EventArgs e)
{
if (radioButton1.Checked)
textBox1.Text = "Radio button 1 checked";
}
I want method to run (event to occur) while i am typing something in textbox ( i dont want to click button) for example i have a a textbox and a listbox in a same form and while i am writing text in textbox it should simultaneously print that in listbox without clicking an button
use Text Changed event for your textbox
Text Changed event
Utilize the TextBox control's TextChanged event.
This event is raised if the Text property is changed by either a programmatic modification or user interaction.
For more information about handling events, see Handling and Raising Events.
You can access it through the properties list, or you can create it at Initialize or Form_Load or even in the Form constructor using:
textBox1.TextChanged += textBox1_TextChanged;
private void textBox1_TextChanged(object sender, EventArgs e) { }
I have a user control in c# where I am dynamically adding textboxes based on run-time user selections. I need to raise a lost focus (or leave?) event for these text boxes. Any suggestions?
When you create a textbox, add this line :
mytextBox.LostFocus += TextBox_LostFocus;
note that when you write += intellisense automatically suggest to press tab to automatic creation of the handler function. If you press tab twice you will get
private void TextBox_LostFocus(object sender, RoutedEventArgs e)
{
throw new NotImplementedException();
}
delete throw exception line and replace it with your stuff.
I want to know if the control that got the focus is input control or not using c#
for example
this text box that I am writing the question in it now is input control but the preview text box down there is not because I cant write on it
I need to detect whether or not it is input control and I want to overwrite what being written there also
You want to edit the text people put in your input fields? Add event listeners on the input controls to the text changed event, and run a method that edits the text in the field.
public Form1()
{
InitializeComponent();
TextBox textBox = new TextBox();
textBox.TextChanged += CheckInputText;
}
public void CheckInputText(object sender, EventArgs e)
{
// Modify text in the input control.
}
In WinForms I could handle the Validated event to do something after the user changed text in a TextBox. Unlike TextChanged, Validated didn't fire for every character change; it only fired when the user was done.
Is there anything in WPF I can use to get the same result, an event raised only after the user is done changing the text?
LostFocus will fire when the user moves from your textbox onto any other control.
It seems that there is no native solution.
The LostFocus event is a good idea. But when the user click on Enter, he wants the TextBox to validate the change.
So here is my suggestion : use the LostFocus event and the KeyDown event when the key is Enter.
private void TextBox_LostFocus(object sender, RoutedEventArgs e)
{
// code to lauch after validation
}
private void TextBox_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.Enter)
{
// call the LostFocus event to validate the TextBox
((TextBox)sender).RaiseEvent(new RoutedEventArgs(TextBox.LostFocusEvent));
}
}
LostFocus is not equivalent to Validate. It creates lots of problem when you have multiple text boxes on one screen and every text box has some logic written in Validate. In validate event you can control focus easily but not in LostFocus so easily.
You can also try Binding.ValidationRules
Documented at : http://msdn.microsoft.com/en-us/library/system.windows.data.binding.validationrules.aspx
Here is the article to get started:
How to implement binding validations :
http://msdn.microsoft.com/en-us/library/ms753962.aspx