Question

我对这段代码有两个问题（我可以看到 - ; ^）：

1）如果不满足条件1，则两个验证消息框都显示;我只希望显示一个或另一个给定每个if块的条件。

2）如何验证字符串中相同的大写和小写字符（如果是第2块）？

public partial class Substrings : Form
{
    public Substrings()
    {
        InitializeComponent();
    }
    private void buttonGo_Click(object sender, EventArgs e)
    {
        //validate input for 5 characters and same characters with Equals method
        if (textBox3.TextLength != 5)
        {
            MessageBox.Show("The string must have exactly 5 characters, try again");
            textBox3.Clear();
            textBox3.Focus();
        }
        //validate only unique characters in string
        if (textBox3.Text.Distinct().Count() == 5)
        {
            listBox1.Items.Add(textBox3.Text.Substring(0, 1)); //p
            listBox1.Items.Add(textBox3.Text.Substring(1, 1)); //o
            listBox1.Items.Add(textBox3.Text.Substring(2, 1)); //w
            listBox1.Items.Add(textBox3.Text.Substring(3, 1)); //e
            listBox1.Items.Add(textBox3.Text.Substring(4, 1)); //r
            listBox1.Items.Add(textBox3.Text.Substring(0, 2)); //Po
            listBox1.Items.Add(textBox3.Text.Substring(1, 2)); //ow
            listBox1.Items.Add(textBox3.Text.Substring(2, 2)); //we
            listBox1.Items.Add(textBox3.Text.Substring(3, 2)); //er
            listBox1.Items.Add(textBox3.Text.Substring(0, 3)); //Pow
            listBox1.Items.Add(textBox3.Text.Substring(1, 3)); //owe
            listBox1.Items.Add(textBox3.Text.Substring(2, 3)); //wer
            listBox1.Items.Add(textBox3.Text.Substring(0, 4)); //Powe
            listBox1.Items.Add(textBox3.Text.Substring(1, 4)); //ower
            listBox1.Items.Add(textBox3.Text.Substring(0, 5)); //Power
        }
        else
            MessageBox.Show("The string must have distinct, non-repeating characters");
    }
    private void textBox3_TextChanged(object sender, EventArgs e)
    {
    }
    private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
    }
    private void buttonExit_Click(object sender, EventArgs e)
    {
        Application.Exit();
    }
}

Answer 1

对于第一部分，只需使用else if - 然后只有第一个块不是第二个块才会执行。

对于第二部分，您可以使用ToLower或ToUpper，这样您就可以比较同一案例中的所有字符。

所以，结合这两个变化：

else if (textBox3.Text.ToUpper().Distinct().Count() == 5)

Answer 2

您要验证文本框不应超过5个字符，然后验证它是否需要具有唯一字符。你可以试试这个：

//validate input for 5 characters and same characters with Equals method
if (textBox3.Length != 5)
{
    MessageBox.Show("The string must have exactly 5 characters, try again");
    textBox3.Clear();
    textBox3.Focus();
}
//validate only unique characters in string
else if (textBox3.Text.ToLower().Distinct().Count() != textBox3.Text.Length)
{
    MessageBox.Show("The string must have distinct, non-repeating characters");
}
else
{
    // Do your stuffs here
}

如何在字符串中验证相同的，重复的大写字母和小写字符？

2 个答案: