是否有允许文本框输入数字的代码？

Question

我在 C# windows 窗体中创建了一个航空公司管理程序，我有一个注册表单，有两个字段（文本框）我想以数字形式取值。

Textbox1（电话号码） Textbox2（国民身份证号码）

我希望这些文本框分别接受 11 位和 16 位数字的输入。

虽然我希望文本框使用 (-) 破折号以受限方式进行输入，例如

####-#######（用于Textbox1）

#####-#######-#（用于Textbox2）

还有，代码应该放在哪个块中？

Answer 1

我根据您的示例为 Textbox1 和 Textbox2 设置了“MaxLength”：

####-#######（对于 Textbox1）'MaxLength'=12

#####-#######-#（对于Textbox2）'MaxLength'=15

    private void textBox1_KeyDown(object sender, KeyEventArgs e)
    {
        //Switch is faster than if
        switch (!((e.KeyCode >= Keys.D0 && e.KeyCode <= Keys.D9) || (e.KeyCode >= Keys.NumPad0 && e.KeyCode <= Keys.NumPad9) || e.KeyCode == Keys.Back || e.KeyCode == Keys.Home || e.KeyCode == Keys.End || e.KeyCode == Keys.Left || e.KeyCode == Keys.Right))
        {
            case true:
                e.SuppressKeyPress = true;//Non-numeric characters are not written with this command
                break;
            default:
                switch (e.KeyCode != Keys.Back && e.KeyCode != Keys.Home && e.KeyCode != Keys.End && e.KeyCode != Keys.Left && e.KeyCode != Keys.Right)
                {
                    case true:
                        //This is how the total number of separators is calculated
                        byte j = 0;
                        for (byte i = 0; i < textBox1.Text.Length; i++)
                        {
                            switch (textBox1.Text[i] == '-')
                            {
                                case true:
                                    j++;
                                    break;
                            }
                        }
                        //You can change this section, based on your country's national identification code or phone number
                        switch (j < 5)//Check total separators
                        {
                            case true:
                                switch (textBox1.Text.Length)
                                {
                                    case 4:
                                        textBox1.Text = textBox1.Text + '-';
                                        textBox1.Select(textBox1.TextLength, textBox1.TextLength);
                                        break;
                                }
                                break;
                        }
                        break;
                }
                break;
        }
    }

    private void textBox2_KeyDown(object sender, KeyEventArgs e)
    {
        //Switch is faster than if
        switch (!((e.KeyCode >= Keys.D0 && e.KeyCode <= Keys.D9) || (e.KeyCode >= Keys.NumPad0 && e.KeyCode <= Keys.NumPad9) || e.KeyCode == Keys.Back || e.KeyCode == Keys.Home || e.KeyCode == Keys.End || e.KeyCode == Keys.Left || e.KeyCode == Keys.Right))
        {
            case true:
                e.SuppressKeyPress = true;//Non-numeric characters are not written with this command
                break;
            default:
                switch (e.KeyCode != Keys.Back && e.KeyCode != Keys.Home && e.KeyCode != Keys.End && e.KeyCode != Keys.Left && e.KeyCode != Keys.Right)
                {
                    case true:
                        //This is how the total number of separators is calculated
                        byte j = 0;
                        for (byte i = 0; i < textBox2.Text.Length; i++)
                        {
                            switch (textBox2.Text[i] == '-')
                            {
                                case true:
                                    j++;
                                    break;
                            }
                        }
                        //You can change this section, based on your country's national identification code or phone number
                        switch (j < 14)//Check total separators
                        {
                            case true:
                                switch (textBox2.Text.Length)
                                {
                                    case 5:
                                        textBox2.Text = textBox2.Text + '-';
                                        textBox2.Select(textBox2.TextLength, textBox2.TextLength);
                                        break;
                                    case 13:
                                        textBox2.Text = textBox2.Text + '-';
                                        textBox2.Select(textBox2.TextLength, textBox2.TextLength);
                                        break;
                                }
                                break;
                        }
                        break;
                }
                break;
        }
    }

输出：

测试于：

Visual Studio 2017、.NET Framework 4.5.2、Windows 窗体

谢谢