CODEWITHSUNDEEP
c#
Mariles
Mariles

Reputation: 83

Focus leave text box

I have a text box TB and a handler EH for the event Focus / Leave.

Also, I have a button BT to quit the program when clicked, only dispose(); If I leave TB box without proper data in it, the focus leave event handler is triggered to check the data, it warns me and return focus back to TB.

But if I want to quit the program while TB has the focus and click BT, again the EH is triggered and returns the focus to TB and the program won't quit.

How can I solve this matter? Here's the code :

public Form1()
{
    InitializeComponent();
}

private void EH(object sender, EventArgs e) // event handler EH
{
    double temp;
    if (TB.Text == "")
    {
        MessageBox.Show("Must enter a valid distance for d1!\r\n" +
            "The valid range is ( 10,32 )",
            "Wake up!", MessageBoxButtons.OK, MessageBoxIcon.Error);
            TB.Focus();
            return;
    }
    else
    try
    {
        temp = Convert.ToDouble(TB.Text);
        if (temp < 10 || temp > 32)
        {
            MessageBox.Show("Invalid distance for d1!\r\n" +
            "The valid range is ( 10,32 )",
            "Again! Wake up!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                TB.Text = "";
                TB.Focus();
                return;
        }
        minh1 = 1 / 8 * temp; // sets minimum h1
            if (minh1 < 10)
                minh1 = 10;
    }
    catch (Exception) // can't convert
    {
        MessageBox.Show("Invalid numeric entry!\r\n" +
        "Please enter a valid number!",
        "Hey! Wake up!", MessageBoxButtons.OK, MessageBoxIcon.Error);
         TB.Text = "";
         TB.Focus();
    }
}

private void TB_TextChanged(object sender, EventArgs e) // change text in TB
{
    if (TB.Text == "")
        btgo.Enabled = false;
    else
        btgo.Enabled = true;
}
private void btgo_Click(object sender, EventArgs e) // Execute!
{
    say.Text = "Minimum height h1 has been calculated to be " +
    string.Format("{0:#0.00}", minh1) + " Fts";
    BT.Focus();
}
private void BT_Click(object sender, EventArgs e) // --- PROGRAM END ---
{
    Dispose();
}

Upvotes: 1

Views: 1351

Answers (2)

Omri Btian
Omri Btian

Reputation: 6547

Keep an indicator that states whether an exit request was made.

private bool _isQuitRequested = false;

In the BT click event add 

private void BT_Click(object sender, EventArgs e) // --- PROGRAM END ---
{
    _isQuitRequested = true;
    Dispose();
}

In the begining of the event handler EH add

if (_isQuitRequested) return;

Don't forget to change _isQuitRequest back to false in TB_TextChanged

Upvotes: 1

devavx
devavx

Reputation: 1045

You can try to create a global field to store permission for the program to exit,like this;

bool Quit=false;

Now when you've done some checks whether to exit the program,you can set this variable to true or false in case something is left.From now onwards whenever the BT_Click event is fired(the Exit event) set this variable to true,like this;

private void BT_Click(object sender, EventArgs e) //--- PROGRAM END ---
{
    Quit = true;//Flag to exit the program.
    Dispose();
}

When you've don this add this code at the very beginning of EH;

private void EH(object sender, EventArgs e) // event handler EH
{
 if(Quit)//If Quit is true,means exit the program.
 {
   return;//No processing,just return.
 }
   //Run regular logic,if the function doesn't need to return.
}

But to make sure that the logic in EH runs,set Quit to false in the TextChangedEvent,like this;

private void TB_TextChanged(object sender, EventArgs e) // change text in TB
{
Quit=false;//Set this to false to make sure `EH` event's code is executed.
if (TB.Text == "")
    btgo.Enabled = false;
else
    btgo.Enabled = true;
}

Upvotes: 0

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