C＃Textbox textchange属性事件

Question

What is the best possible way to enable the visibility of a label inside a form.

If you see the code below .

 public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        lblgrpTwoFirst.Visible = false;
        lblgrpTwoSecond.Visible = false;
        lblgrpTwoThird.Visible = false;
        lblgrpTwoFourt.Visible = false;
    }

    private void txtboxOne_TextChanged(object sender, EventArgs e)
    {
        if (txtboxOne.Text == "z")
        {
            MessageBox.Show("The Goose Eat the Beans");
        }

        else if (txtboxTwo.Text == "x")
        {
            lblgrpTwoSecond.Visible = true;
        }

Why does that label doesn't show up? But if try to make a messagebox . a messagebox pops up.

Answer 1

You are checking the value of txtboxTwo in the TextChanged event of txtboxOne .

That is why messagebox block works and the later block does not.

Change it to:

private void txtboxOne_TextChanged(object sender, EventArgs e)
{
    if (txtboxOne.Text == "x")
    {
        lblgrpTwoSecond.Visible = true;
    }
}

Answer 2

if you indeed want to check txtboxTwo.Text dont use else if, use if:

 private void txtboxOne_TextChanged(object sender, EventArgs e)
    {
        if (txtboxOne.Text == "z")
        {
            MessageBox.Show("The Goose Eat the Beans");
        }

        if (txtboxTwo.Text == "x")
        {
            lblgrpTwoSecond.Visible = true;
        }
    }

Answer 3

检查你的条件

 lblgrpTwoSecond.Visible = txtboxTwo.Text == "x" ? true : false;