如何在 c# winforms 中的所有文本框不为空后启用按钮？

Question

How can I make button property set to enabled=true after all my textboxes are not empty? I'm learning programming and my apps are simple.

I know how to enable this property when one of my textboxes have text but this is not the case.

Use case is that user need to put data in both textboxes and after that will be able to click btn. How in most simple way can I validate all form and then enable button?

There are just 2 tb: https://i.imgur.com/JUslNWE.png

Answer 1

You need to create a TextBox_TextChanged event and subscribe to all text boxes.

private void TextBox_TextChanged(object sender, EventArgs e)
{
    int notEmptyTextBoxCount = 0;
    int textBoxCount = 0;
    foreach (var item in Controls)
    {
        if (item is TextBox txtb)
        {
            textBoxCount++;
            if (txtb.Text != String.Empty)
                notEmptyTextBoxCount++;
        }
    }
    if (textBoxCount == notEmptyTextBoxCount)
        button.Enabled = true;
    else
        button.Enabled = false;
}

Answer 2

Thanks guys for all feedback.

I have managed to do this this way:

private void ValidateTextBoxes()
    {
        if (loginTextBox.Text.Length != 0 && passTextBox.Text.Length != 0)
        {
            generateHashBtn.Enabled = true;
        }
        else
        {
            generateHashBtn.Enabled = false;
        }
    }

    private void TextBox1_TextChanged(object sender, EventArgs e)
    {
        ValidateTextBoxes();
    }

    private void TextBox2_TextChanged(object sender, EventArgs e)
    {
        ValidateTextBoxes();
    }