Disable textbox after typing in a value C# - c#

I want to disable a textbox after user has inserted a value. I have tried playing with the "KeyPress" property but the first digit I type in is also the "KeyPress", so it locks on the first character. Maybe I can get the textbox to lock after pressing Enter or using Tab. What will be the best way to do this?

It sounds like you want to disable the box after the person leave it. (I assume that from your Enter/Tab option.) If so, look into the TextBox.LostFocus event.

Though, the "Best" generally depends on the customer requirement, I would do the disabling act on the Lost Focus event.
private void textBox2_Leave(object sender, EventArgs e)
{
textBox2.Enabled = false;
}
Thanks

Just use Leave event and in body assign Enabled to false;

you can use the LostFocus event or the ManipulationCompleted event handler

Related

How to open a link from a rich text box [duplicate]

When I add www.stackoverflow.com into my RichTextBox and run the program it is shown in blue and as a hyperlink yet when I click it nothing happens. How can I fix this?
Make sure the text property includes a valid url. E.g. http://www.stackoverflow.com/
set the DetectUrls property to true
Write an event handler for the LinkClicked event.
Personally, I wouldn't pass "IExplore.exe" in as a parameter to the Process.Start call as Microsoft advise as this presupposes that it is installed, and is the user's preferred browser. If you just pass the url to process start (as per below) then Windows will do the right thing and fire up the user's preferred browser with the appropriate url.
private void mRichTextBox_LinkClicked (object sender, LinkClickedEventArgs e) {
System.Diagnostics.Process.Start(e.LinkText);
}
RichTextBox class allows you to customize its behavior when user clicks the hyperlink. Add an event handler for the RichTextBox.LinkClicked event
Process p = new Process();
private void richTextBox1_LinkClicked(object sender, LinkClickedEventArgs e)
{
p = Process.Start("IExplore.exe", e.LinkText);
}
You should make sure that DetectUrls is set to true. If that doesn't work on its own, you may need to add a handler for the LinkClicked event.
Is yourTextBox.DetectUrls set to true? We may need some more info to provide a better answer.

Do not allow Enter Key to make a new line in MultiLine TextBox C#

I set the property Multiline=true;.
I do not want to allow the Enter Key to make a new line.
How can I solve this issue?
That could be as simple as listening to TextChanged event and then executing the following line inside it:
txtYourTextBox.Text = txtYourTextBox.Text.Replace(Environment.NewLine, "");
This solution involves some screen flicker though. A better way is to prevent it entirely by listening to KeyDown event:
private void txtYourTextBox_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
e.SuppressKeyPress=true;
}
Well, I am quite late to the party, but for others who read this I would mention that there is a property named TextBox.AcceptsReturn (Boolean).
Just set it in the properties window of the TextBox.
I had the same problem just the other way round: I had a multiline TextBox, but it didn't allow me to enter Returns.
Further information here:
https://learn.microsoft.com/dotnet/api/system.windows.forms.textbox.acceptsreturn?view=net-5.0

How can I know Text changes for textboxes without Textchanged event

In my C# Windows form MyForm I have some TextBoxes.
In these TextBoxes, we have to detect if the TextChanged event occurs,
if there're changes in these TextBoxes and click close button, it will ask if we want to cancel the changes when we close the form.
However, when I run the MyForm, I can't know text change for each textbox caused by user typing for without textchanged event property.
But I am thinking how do I make the TextBox's TextChanged know the
event cuased by user typing without textchanged event?
Thanks for help.
Sorry for my English.
There is no (decent) way of knowing what's typed without a TextChanged or a Leave event.
You need to use one of these events to get the typed content. Doing this enable you to set a "dirty" flag that you can check at close and clear at save.
Comparing old and new value has no point without this cause you won't know what the value should be set to without knowing something was changed.
With one exception: If your original data came from a database you could use the compare old/new approach as you would compare the textbox of that which came from the database.
Update:
Addressing this comment:
"Because Myform have many textboxes and if no text change ,this will
not display the confirm message.If I catch textchanged event for all
textboxes, this is so many code."
You can use a common handler to collect the changes for all textboxes in one single method. Use the sender object (cast it to Textbox) to identify which textbox is changed, if needed, or simply set a dirty flag for whatever textbox has a change.
bool isDirty = false;
void SomeInitMethod() //ie. Form_Load
{
textbox1.TextChanged += new EventHandler(DirtyTextChange);
textbox2.TextChanged += new EventHandler(DirtyTextChange);
textbox3.TextChanged += new EventHandler(DirtyTextChange);
//...etc
}
void DirtyTextChange(object sender, EventArgs e)
{
isDirty = true;
}
void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
if (isDirty) {
//ask user
}
}
// to clear
void Save()
{
SaveMyDataMethod();
isDirty = false;
}
If you have a lot of textboxes in the form loop through the forms control collection and use typeof to address the textboxes. If you have textboxes requiring different approaches use the Tag property of the textbox to distinguish.
A possible approach is using the timer. Have a timer that ticks every 1000 ms (say) and checks the textBox.Text.
A second possible approach is overriding WndProc for the textbox (by inheriting a new class) and handling the change text message. This would be the same as overriding TextBox.OnTextChanged.
Why dont you use a timer which will check after a few intervals if the textboxes do contain any text

How do I enable button while there is a string in my textbox?

I have a textbox and a button in form2. When an item is clicked in form1, form2 appears. I would like to keep the button in form2 disabled while the textbox is empty, but when user starts typing, I'd like to enable the button.
I have tried using an if in my constructor after the initialisecomponent() like so, but it does not work:
if(textbox1.text != "")
{
btnOne.Enabled = true;
}
I have also tried calling a method called checkText() after the initialise component which uses a do-while loop to check like:
do{
btnOne.Enabled = true
}
while(textbox1.text != "");
Can anyone help?
You need to use an event. Check out the TextChanged event for the TextBox control.
Basically you will want something like this:
private void textbox1_TextChanged(object sender, EventArgs e)
{
btnOne.Enabled = !string.IsNullOrEmpty(textbox1.Text);
}
If you are using Visual Studio you can do the following to add the event code.
Open designer view
Select the TextBox control
View the "Events" window
Find the "TextChanged" event
Double-click the value space, and the code will be added automatically for you to work with
Note: This approach will require the user to "lose focus" on the TextBox control before the event fires. If you want an as-you-type solution then check out the KeyUp event instead
#Asif has made a good point regarding checking for whitespace characters too. This is your call on what is valid, but if you do not want to allow whitespace value to be used then you can use the IsNullOrWhiteSpace method instead - however, this requires you to be using .Net Framework 4.0 or higher
Use Textbox changed event in windows form
In case you don't allow white spaces as a valid input then you should use string.IsNullOrWhiteSpace instead of string.IsNullOrEmpty.
textbox1.TextChanged += (sender, e)
{
btnOne.Enabled = !string.IsNullOrWhiteSpace(textbox1.Text);
};

How can I make a hyperlink work in a RichTextBox?

When I add www.stackoverflow.com into my RichTextBox and run the program it is shown in blue and as a hyperlink yet when I click it nothing happens. How can I fix this?
Make sure the text property includes a valid url. E.g. http://www.stackoverflow.com/
set the DetectUrls property to true
Write an event handler for the LinkClicked event.
Personally, I wouldn't pass "IExplore.exe" in as a parameter to the Process.Start call as Microsoft advise as this presupposes that it is installed, and is the user's preferred browser. If you just pass the url to process start (as per below) then Windows will do the right thing and fire up the user's preferred browser with the appropriate url.
private void mRichTextBox_LinkClicked (object sender, LinkClickedEventArgs e) {
System.Diagnostics.Process.Start(e.LinkText);
}
RichTextBox class allows you to customize its behavior when user clicks the hyperlink. Add an event handler for the RichTextBox.LinkClicked event
Process p = new Process();
private void richTextBox1_LinkClicked(object sender, LinkClickedEventArgs e)
{
p = Process.Start("IExplore.exe", e.LinkText);
}
You should make sure that DetectUrls is set to true. If that doesn't work on its own, you may need to add a handler for the LinkClicked event.
Is yourTextBox.DetectUrls set to true? We may need some more info to provide a better answer.

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