驗証TextBox輸入的文本

代碼如下:

public partial class Textboxtext : Form
    ...{
        public Textboxtext()
        ...{
            InitializeComponent();
            btnClose.CausesValidation = false;//當單擊按鈕時不考慮驗証狀態
            txtUsename.Tag = false;
            txtAddress.Tag = false;
            txtAge.Tag = false;
            txtOccupation.Tag = false;
            btnOK.Enabled = false;
            txtUsename.Validating += new CancelEventHandler(txtBoxEmpty_Validating);
            txtAddress.Validating += new CancelEventHandler(txtBoxEmpty_Validating);
            txtOccupation.Validating += new CancelEventHandler(txtOccupation_Validating);
            txtAge.KeyPress += new KeyPressEventHandler(txtAge_KeyPress);
            txtAge.Validating += new CancelEventHandler(txtBoxEmpty_Validating);
            txtUsename.TextChanged += new EventHandler(txt_TextChanged);
            txtAddress.TextChanged += new EventHandler(txt_TextChanged);
            txtOccupation.TextChanged += new EventHandler(txt_TextChanged);
            txtAge.TextChanged += new EventHandler(txt_TextChanged);
            Combox.KeyDown += new KeyEventHandler(Combox_KeyDown);

            LoadCombox();
        }

        void Combox_KeyDown(object sender, KeyEventArgs e)
        ...{
            int index = 0;
            ComboBox cbo = (ComboBox)sender;
            if (e.KeyCode == Keys.Enter)
            ...{
                index = cbo.FindStringExact(cbo.Text);
                if (index < 0)
                    cbo.Items.Add(cbo.Text);
                //else cbo.SelectedIndex = index;
            }
            if (e.KeyCode == Keys.Delete)
            ...{
                index = cbo.FindStringExact(cbo.Text);
                if (index > -1)
                    cbo.Items.Remove(cbo.Text);
            }
        }
        void LoadCombox()
        ...{
            string FilePath = Application.StartupPath + @" xt.txt";
            bool exist = File.Exists(FilePath);
            if (exist == false)
            ...{
                Directory.CreateDirectory(Application.StartupPath);
                FileStream fs = new FileStream(FilePath, FileMode.Create);
                fs.Close();
            }
            System.IO.StreamReader sr = new System.IO.StreamReader(FilePath);
            try
            ...{

                string input;
                do
                ...{
                    input = sr.ReadLine();
                    if (input != ""&&input!=null)
                        Combox.Items.Add(input);
                }
                while (sr.Peek() != -1);
                sr.Close();
            }
            catch (Exception)
            ...{
                MessageBox.Show("沒有找到相關文件");
            }
            //finally
            //{ }
        }
        void SaveCombox()
        ...{
            try
            ...{
                System.IO.StreamWriter sw = new System.IO.StreamWriter(Application.StartupPath + @" xt.txt");
                foreach (string item in Combox.Items)
                    sw.WriteLine(item);
                sw.Flush();
                sw.Close();
            }
            catch (Exception err)
            ...{
                MessageBox.Show(err.Message);
            }
        }

        void txt_TextChanged(object sender, EventArgs e)
        ...{ 
            TextBox tb = (TextBox)sender;
            if (tb.Text.Length == 0 && tb != txtOccupation)
            ...{
                tb.BackColor = Color.Purple;
                tb.Tag = false;
            }
            else if (tb == txtOccupation && (txtOccupation.Text.Length != 0 && tb.Text.CompareTo("程序員") != 0))
            ...{
                tb.BackColor = Color.Purple;
                tb.Tag = false;
            }
            else
            ...{
                tb.BackColor = SystemColors.Window;
                tb.Tag = true;
            }
            ValidateAll();
        }

        void txtOccupation_Validating(object sender, CancelEventArgs e)
        ...{
            TextBox tb = (TextBox)sender;
            if (tb.Text.CompareTo("程序員") == 0 || tb.Text.Length == 0)
            ...{
                tb.BackColor = SystemColors.Window;
                tb.Tag = true;
            }
            else
            ...{
                tb.BackColor = Color.Purple;
                tb.Tag = false;
            }
            ValidateAll();
        }

        void txtAge_KeyPress(object sender, KeyPressEventArgs e)
        ...{
            if ((e.KeyChar < 48 || e.KeyChar > 57)&&e.KeyChar!=8)//ASC值8表示退位鍵
                e.Handled = true;
        }

        void txtBoxEmpty_Validating(object sender, CancelEventArgs e)
        ...{
            TextBox tb = (TextBox)sender;
            if (tb.Text.Length == 0)
            ...{
                tb.BackColor = Color.Purple;
                tb.Tag = false;
                //e.Cancel = true;
            }
            else
            ...{
                tb.BackColor = SystemColors.Window;
                tb.Tag = true;
            }
            ValidateAll();
        }
        private void btnOK_Click(object sender, EventArgs e)
        ...{
            string outputtxt;
            outputtxt = "Usename:" + txtUsename.Text + Environment.NewLine;
            outputtxt += "Address:" + txtAddress.Text + " ";
            outputtxt += "Occupation:" + txtOccupation.Text + " ";
            outputtxt += "Age:" + txtAge.Text + " ";
            outputtxt += "Sex:" +(string)(RdoMale.Checked ? "Male" : "Female") + " ";
            outputtxt += "星座:" + Combox.Text + " ";
            txtOutput.Text += outputtxt;
        }

        private void btnHelp_Click(object sender, EventArgs e)
        ...{
            string outputtxt;
            outputtxt = "Usename: 用戶名(不能為空)" + Environment.NewLine;
            outputtxt += "Address: 地址(不能空空) ";
            outputtxt += "Occupation: 職業(必須是程序員或為空) ";
            outputtxt += "Age: 年齡(大於或等於零的一個數字) ";
            outputtxt += "Sex: 性別 ";
            outputtxt += "星座: 所屬星座 ";
            txtOutput.Text += outputtxt;
        }
        void ValidateAll()
        ...{
            btnOK.Enabled = (bool)txtUsename.Tag && (bool)txtAddress.Tag && (bool)txtAge.Tag && (bool)txtOccupation.Tag;
        }

        private void btnClose_Click(object sender, EventArgs e)
        ...{
            Application.Exit();
        }
    }

 運行效果: