I'm creating a clipboard editing program and I encountered an error when I use the Copy button. If the text box from where it copies to the clipboard's contents are null, then I get a "ArgumentNullException was not handled". I know this is because the TextBox it copies the text from is empty. I want to write a method where if the TextBox is empty, then the button is disabled. Here is the code for this button:
// Copies the text in the text box to the clipboard.
private void copyButton_Click(object sender, EventArgs e)
{
Clipboard.SetText(textClipboard.Text);
}
Any and all help is appreciated. If I'm missing some more details please let me know so I can add them.
You have to initially set the button to be disabled.
Then you can use that code to detect the change in the text box:
private void textClipboard_TextChanged(object sender, EventArgs e)
{
copyButton.Enabled = textClipboard.Text.Length > 0;
}
You should check for null:
// Copies the text in the text box to the clipboard.
private void private void textClipboard_LostFocus(object sender, System.EventArgs e)
{
if(!string.IsNullOrEmpty(textClipboard.Text)
{
Clipboard.SetText(textClipboard.Text);
}
else
{
copyButton.Enabled = false; //Set to disabled
}
}
You could initially set the button.enabled to false, and add a KeyUp event to your textbox:
private void textClipboard_KeyUp(object sender, KeyEventArgs e)
{
copyButton.Enabled = !string.IsNullOrEmpty(textBox1.Text);
}
Related
I learned how to have a textbox and when the value is empty the button is disabled and when I enter a value in the textbox the button is enabled.
Now I want to have a login form that contains one textbox (for username) and another textbox (for password), so here I learned how to code.
But how should I write the code so that when the condition (both text boxes are empty) the button is disabled and when the condition is (both text boxes have values) the button is enabled.
Try this:
private void txtUserName_TextChanged(object sender, EventArgs e)
{
CheckFields();
}
private void txtPassword_TextChanged(object sender, EventArgs e)
{
CheckFields();
}
private void CheckFields()
{
btnLogin.Enabled = txtPassword.Text.Length == 0 || txtUserName.Text.Length == 0 ? false : true;
}
I assume that your username textbox is named, txtUserName, and your password textbox is named, txtPassword. Also the login button is named, btnLogin. I recommend setting the btnLogin enabled property to false when the form first loads. You can set that in the form's Load event:
private void Form1_Load(object sender, EventArgs e)
{
btnLogin.Enabled = false;
}
I think it would be better if you implement this logic on the client side (javascript), it is unnecessary to go to the server again and again for every text change.
you should add onclick function on username and password textboxes and implement the logic to check whether both have values then enable the button else disable it.
You should add the TextChanged event for both boxes and have it be something like this:
private void CheckTextboxes(object sender, EventArgs e)
{
if (string.IsNullOrWhiteSpace(txtUsername.Text) || string.IsNullOrWhiteSpace(txtPassword.Text))
{
button.Enabled = false;
return;
}
button.Enabled = true;
}
private void txtUsername_TextChanged(object sender, EventArgs e)
{
CheckTextboxes();
}
private void txtPassword_TextChanged(object sender, EventArgs e)
{
CheckTextboxes();
}
That way you ensure that if the user enters values on the textboxes in either order the button only enables if both have actual text written on them.
I'm building a WinFormApplication which allow the user to drag a document into a richTextBox which is loading the files content to the richTextBox. However the TextChange-event doesn't seem to happend emedietly after the text is changed, why could this be?
private void richTextBox_DragDrop(object sender, DragEventArgs e)
{
....
....
richTextBox.Text = content;
hasBeenEdited = false;
}
private void Form1_TextChanged(object sender, EventArgs e)
{
....
hasBeenEdited = true;
}
In the code above I have one DragDrop-event, the content of a file replaces the current richTextBox text. However the has been edited flag first get set to false, then true. I was hoping the flag would be set to true then false. How can I fix this?
Thanks!
Most of my dropdown boxes use the SuggestAppend property, meaning when you start typing in the box, it will make a shortlist of the items that match your case. However, if I do this after opening the drawer, this happens:
I have tried using this method, but it closes both instead of just one:
private void cmbLoc_TextChanged(object sender, EventArgs e)
{
if (cmbLoc.Text != "")
{
cmbLoc.DroppedDown = false;
}
}
I am trying to have it so that when I type something into the text box, the original dropdown will disappear, and the SuggestAppend draw will appear. How can I manage this?
It worked if I used KeyDown. Try and tell if that helps
private void cmbLoc_KeyDown(object sender, KeyEventArgs e)
{
var comboBox = (ComboBox)sender;
comboBox.DroppedDown = false;
}
I have a textbox and it's readonly. When I click on I want it to call my button click event:
private void tbFile_Click(object sender, EventArgs e)
{
//btnBrowse_Click(sender, e);
MessageBox.Show("test");
}
When click on the textbox, nothing happens. How do I fix it?
Update:
private void btnBrowse_Click(object sender, EventArgs e)
{
openFile();
}
private void tbFile_Click(object sender, EventArgs e)
{
//btnBrowse_Click(sender, e);
if (tbFile.Text != "")
{
openFile();
}
}
public void openFile()
{
var FD = new System.Windows.Forms.OpenFileDialog();
FD.Filter = "DBF Files|*.DBF";
FD.InitialDirectory = #"C:\";
if (FD.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
string fileToOpen = FD.FileName;
tbFile.Text = fileToOpen;
}
}
When I hit browse button and select a file, the browse file window comes up again. So it's appearing twice now and the textbox click is still not working.
There is no reason that can be inferred from the information you provided why you shouldn't trigger the openFile() method when you click on the tbFile control.
The fact that the textbox is set to readonly does not stop it from raising the click event in any way.
The only possibility is that the method is not assigned to the click event of the control.
Make sure in the event properties of the control that the click event is indeed assigned to the "tbFile_Click" method.
Just because there exsits a method that's called the same as a control but has "_Click" added does not make it get executed unless you specifically tell c# you want to associate that method with the click event of the control.
When you assign the method through the event window, C# generates a code file behind the scenes that adds the callback to that specific event.
You should use the btnBrowse.PerformClick() method to simulate a user click, instead of calling the handler.
The default I got from VS 2013 was a 'MouseClick' function so this works:
private void btnBrowse_Click(object sender, EventArgs e)
{
MyAwesomeFunction(sender);
}
private void tbFile_MouseClick(object sender, MouseEventArgs e)
{
MyAwesomeFunction(sender);
}
private void MyAwesomeFunction(object sender)
{
MessageBox.Show("test");
}
i have a from c# and i want to show text Box after a click in a check box.
but when i scroll down, and check , the text Box is shown in the wrong place !!!
the text Boxes must be in the same level with check Boxes.
private void checkBox1_Checkedchanged(object sender, EventArgs e)
{
textBox1.Visible = true;
}
and changing the Location of the text Box don't give good results !
thanks for help.
You are running into an awkward quirk of the Panel control, it only scrolls controls that are visible. When you make it visible in your code, it will have the wrong Location property if you've used the scrollbar. You will need to make the correction yourself. Make it look like this:
private void checkBox1_Checkedchanged(object sender, EventArgs e)
{
if (!textBox1.Visible) {
textBox1.Location = new Point(textBox1.Left + panel1.AutoScrollPosition.X,
textBox1.Top + panel1.AutoScrollPosition.Y);
textBox1.Visible = true;
}
}
A better alternative is to use the Enabled property instead, also much less disorienting for the user. Set it to False in the designer and then:
private void checkBox1_Checkedchanged(object sender, EventArgs e)
{
textBox1.Enabled = true;
}