I have a window with a TextBox and a Button. I want to always focus my TextBox, but allow the user to click the button. How can I do it?
I tried it by using a LostFocusEvent, that whould check who has the focus, and if it wasn't the Button it would focus the TextBox back, but I always get a System.StackOverflowException...
This what I was using:
private void TextLostFocus(object sender, RoutedEventArgs e)
{
IInputElement focusedControl = FocusManager.GetFocusedElement(this);
if (focusedControl != btn && focusedControl != txt)
{
txt.Focus();
}
}
Is there a way to do this?
in the button click event you can give focus back to your text box like this.
textbox.focus();
Textbox.Select();
Focus is a lower level method used for custom controls. I would stick to select() or activate()
private void TextLostFocus(object sender, RoutedEventArgs e)
{
((TextBox) sender).Focus();
}
you could use ActiveControl Property to set focus to your text box.
this.ActiveControl = yourTextboxName;
Related
In my C# form I want to disable my button whenever I input some text on the textbox. Is there any best way to do this ?
Set the button.Enabled property in the TextChanged event:
private void textBox1_TextChanged(object sender, EventArgs e)
{
button1.Enabled = string.IsNullOrWhiteSpace(textBox1.Text);
}
Hope you are using WPF, if so here is an answer that is very relavent: Enable button based on TextBox value (WPF)
This is probably an easy one for some of you.
I have a TextBox and a ListBox. ListBox provides options for the TextBox and copies selected item's text to TextBox on DoubleClick event. ListBox becomes visible only when TextBox fires Enter event. I do not want to discuss my reasons for selecting this control combination.
I want ListBox to disappear when any other control within the Form gets focus. So I capture Leave event of TextBox and call ListBox.Visible = fale The problem is that TextBox will also loose focus when I click on ListBox to select provided option thus preventing me from selecting that option.
What event combination should I use to preserve ListBox to select option but hide it whenever other controls get focus?
In the Leave method, you can check to see if the ListBox is the focused control or not before changing its Visibility:
private void myTextBox_Leave(object sender, EventArgs e)
{
if (!myListBox.Focused)
{
myListBox.Visible = false;
}
}
This example will provide you with the desired outcome:
public Form1()
{
InitializeComponent();
textBox1.LostFocus += new EventHandler(textBox1_LostFocus);
textBox1.GotFocus += new EventHandler(textBox1_GotFocus);
}
void textBox1_GotFocus(object sender, EventArgs e)
{
listBox1.Visible = true;
}
void textBox1_LostFocus(object sender, EventArgs e)
{
if(!listBox1.Focused)
listBox1.Visible = false;
}
private void listBox1_MouseDoubleClick(object sender, MouseEventArgs e)
{
textBox1.Text = listBox1.SelectedItem.ToString();
}
private void Form1_Shown(object sender, EventArgs e)
{
//if your textbox as focus when the form shows
//this is the place to switch focus to another control
listBox1.Visible = false;
}
1.How to give both lostfocus event and gotfocus event for a textbox at the same time?
2.That is, i have to append % to a text box, so i will use lost focus event.
3.But whenever the user again goes to d text box i need to call got focus event.
4.So is this possible to call both the events of a text box at the same time??
this is for lostfocus event:
protected void lostfocus(object sender, EventArgs e)
{
if (txtMarks.Text != "")
{
txtMarks.Text += "%";
ddlGrade.Focus();
}
else
{
txtMarks.Text = "";
ddlGrade.Focus();
}
}
this is for gotfocus event:
protected void lostfocus(object sender, EventArgs e)
{
if (txtMarks.Text.contains("%"))
{
txtMarks.Text = "";
ddlGrade.Focus();
}
}
If you want to append "%" on lost focus and clear the value when you got focus, maybe you should consider adding a separate label on the right of the textbox with the content "%". In this way the user will know that this is a percentage textbox. What you want to do does not look very nice.
Instead of
if (txtMarks.Text != "")
use this
if(!string.IsNullOrEmpty(txtMarks.Text))
I have made a custom Number Keypad control that I want to place in my winform application. All of the buttons have an OnClick event to send a value to the focused textbox in my form where I have placed my custom control. Like this:
private void btnNum1_Click(object sender, EventArgs e)
{
if (focusedCtrl != null && focusedCtrl is TextBox)
{
focusedCtrl.Focus();
SendKeys.Send("1");
}
}
focusedCtrl is supposed to be set on the MouseDown event of the button like this:
private void btnNum1_MouseDown(object sender, EventArgs e)
{
focusedCtrl = this.ActiveControl;
}
where this.ActiveControl represents the active control on the form.
My problem is that the button always receives the focus before the event detects what the focused control was previously. How can I detect which control had the focus before the button got the focus? Is there another event I should be using? Thanks in advance!
EDIT: Also, I would rather not use the GotFocus event on each textbox in the form to set focusedCtrl since that can be tedious and because I would like to have all the coding of my custom control be in the control itself and not on the form where it is placed. (I will do this, though, if there is no other practical way to do what I am asking)
Your requirement is fairly unwise, you'll want some kind of guarantee that your button isn't going to poke text into inappropriate places. You really do need to have the form co-operate, only it knows what places are appropriate.
But it is not impossible, you can sniff at input events before they are dispatched to the control with the focus. In other words, record which control has the focus before the focusing event is fired. That's possible in Winforms with the IMessageFilter interface.
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 your form, replacing your existing buttons.
using System;
using System.Windows.Forms;
class CalculatorButton : Button, IMessageFilter {
public string Digit { get; set; }
protected override void OnClick(EventArgs e) {
var box = lastFocused as TextBoxBase;
if (box != null) {
box.AppendText(this.Digit);
box.SelectionStart = box.Text.Length;
box.Focus();
}
base.OnClick(e);
}
protected override void OnHandleCreated(EventArgs e) {
if (!this.DesignMode) Application.AddMessageFilter(this);
base.OnHandleCreated(e);
}
protected override void OnHandleDestroyed(EventArgs e) {
Application.RemoveMessageFilter(this);
base.OnHandleDestroyed(e);
}
bool IMessageFilter.PreFilterMessage(ref Message m) {
var focused = this.FindForm().ActiveControl;
if (focused != null && focused.GetType() != this.GetType()) lastFocused = focused;
return false;
}
private Control lastFocused;
}
Control focusedCtrl;
//Enter event handler for all your TextBoxes
private void TextBoxesEnter(object sender, EventArgs e){
focusedCtrl = sender as TextBox;
}
//Click event handler for your btnNum1
private void btnNum1_Click(object sender, EventArgs e)
{
if (focusedCtrl != null){
focusedCtrl.Focus();
SendKeys.Send("1");
}
}
you have an event called lostFocus you can use
button1.LostFocus +=new EventHandler(dataGridView1_LostFocus);
and in the event:
Control lastFocused;
void dataGridView1_LostFocus(object sender, EventArgs e)
{
lastFocused = sender as Control;
}
in that way you can always know what is the Control that was focused previously
now, correct me if i'm wrong, but you do it for the SendKeys.Send("1"); to know which textBox need to receive the number. for that you can use GotFocus event and register only the textBoxs to it.
you can also do what windows is doing and use just one textbox like here:
if it's fits your needs
What about using this with the parameter forward = false?
Control.SelectNextControl Method
You'd probably call it on your "custom Number Keypad control".
I have numeric buttons which when pressed display the number in different text boxes. Now my problem is that i want check which textbox has focus so that the number pressed will be entered in that textbox.
My Code:
private void btn_one_Click(object sender, EventArgs e)
{
if (txt_one.Focused==true)
{
txt_one.Text += btn_one.Text;
}
else if (txt_two.Focused==true)
{
txt_two.Text += btn_one.Text;
}
}
Now my problem is that the above code is not working what is wrong and what will be the solution? I even used something like this
private void btn_one_Click(object sender, EventArgs e)
{
if (txt_one.Focus()==true)
{
txt_one.Text += btn_one.Text;
}
else if (txt_two.Focus()=true)
{
txt_two.Text += btn_one.Text;
}
}
In both the above cases the text is entered in both the text boxes. Any solutions.
This problem is a little tricky (with my experience dealing with Enter, Focus, LostFocus, Leave events, all these things sometimes make your head ache a lot and you should avoid dealing with them if possible), at the time you click your Button, the current Focused control you can know is exactly the Button (ActiveControl is one short way to access it). So the solution is we have to record the track of focused TextBox, hold it in a reference and use it when needed. In fact if the control other than one of your TextBoxes is focused, we have to reset the variable lastFocused to null:
TextBox lastFocused;
//Enter event handler for all your TextBoxes
private void TextBoxes_Enter(object sender, EventArgs e){
lastFocused = sender as TextBox;
}
//Click event handler for your button
private void btn_one_Click(object sender, EventArgs e){
if(lastFocused != null) lastFocused.Text += btn_one.Text;
}