controlemployees.cs

用VS。NET基于wince

            // 
            // labelTitle
            // 
            this.labelTitle.Font = new System.Drawing.Font("Microsoft Sans Serif", 7.8F, System.Drawing.FontStyle.Bold);
            this.labelTitle.Location = new System.Drawing.Point(8, 48);
            this.labelTitle.Size = new System.Drawing.Size(44, 16);
            this.labelTitle.Text = "Title:";
            this.labelTitle.TextAlign = System.Drawing.ContentAlignment.TopRight;
            // 
            // comboBoxEmployees
            // 
            this.comboBoxEmployees.Enabled = true;
            this.comboBoxEmployees.Location = new System.Drawing.Point(64, 16);
            this.comboBoxEmployees.Size = new System.Drawing.Size(160, 21);
            // 
            // ControlEmployees
            // 
            this.Controls.Add(this.buttonSave);
            this.Controls.Add(this.labelAddress);
            this.Controls.Add(this.labelEmployee);
            this.Controls.Add(this.textBoxEmployeeID);
            this.Controls.Add(this.labelEmployeeID);
            this.Controls.Add(this.textBoxHireDate);
            this.Controls.Add(this.textBoxTitle);
            this.Controls.Add(this.textBoxHomePhone);
            this.Controls.Add(this.labelHomePhone);
            this.Controls.Add(this.textBoxPostalCode);
            this.Controls.Add(this.textBoxRegion);
            this.Controls.Add(this.textBoxCity);
            this.Controls.Add(this.textBoxAddress);
            this.Controls.Add(this.labelHireDate);
            this.Controls.Add(this.labelTitle);
            this.Controls.Add(this.comboBoxEmployees);
            this.Size = new System.Drawing.Size(246, 302);
        }
		#endregion
		

        // This function initializes or refreshes the Employees DataSet.
        //
        public void InitEmployees() {

            // Starts the cursor icon since this function may take some time.
            //
            System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.WaitCursor;

            SqlCeConnection cnNorthwind = NorthwindData.GetInstance().NorthwindConnection;
            DataSet dsNorthwind = NorthwindData.GetInstance().NorthwindDataSet;
            DataTable dtEmployees = null;

            try {
                // This will execute only the first time the InitEmployees method is called.
                //
                if (null == daEmployees) {
                    daEmployees = new SqlCeDataAdapter(@"SELECT EmployeeID, LastName + ', ' + firstName AS Name, Title, HireDate, Address, City, Region, PostalCode, HomePhone FROM Employees ORDER BY Name", cnNorthwind);
                    daEmployees.UpdateCommand = new SqlCeCommand();
                    daEmployees.UpdateCommand.Connection = cnNorthwind;
                    
                    // The Address, City, PostalCode, Title, HomePhone, and Region fields can be updated.
                    //
                    daEmployees.UpdateCommand.CommandText = 
                        @"UPDATE Employees SET Address = ?, City = ?, PostalCode = ?, Title = ?, HomePhone = ?, Region = ? WHERE (EmployeeID = ?)";
                    
                    daEmployees.UpdateCommand.Parameters.Add(
                        new SqlCeParameter("@Address", System.Data.SqlDbType.NVarChar, 60, "Address"));
                    
                    daEmployees.UpdateCommand.Parameters.Add(
                        new SqlCeParameter("@City", System.Data.SqlDbType.NVarChar, 15, "City"));
                    
                    daEmployees.UpdateCommand.Parameters.Add(
                        new SqlCeParameter("@PostalCode", System.Data.SqlDbType.NVarChar, 10, "PostalCode"));
                    
                    daEmployees.UpdateCommand.Parameters.Add(
                        new SqlCeParameter("@Title", System.Data.SqlDbType.NVarChar, 30, "Title"));
                    
                    daEmployees.UpdateCommand.Parameters.Add(
                        new SqlCeParameter("@HomePhone", System.Data.SqlDbType.NVarChar, 24, "HomePhone"));
                    
                    daEmployees.UpdateCommand.Parameters.Add(
                        new SqlCeParameter("@Region", System.Data.SqlDbType.NVarChar, 15, "Region"));
                    
                    daEmployees.UpdateCommand.Parameters.Add(
                        new SqlCeParameter("@Original_EmployeeID", System.Data.SqlDbType.Int, 4, false, ((System.Byte)(0)), ((System.Byte)(0)), "EmployeeID", System.Data.DataRowVersion.Original, null));
                }
                dtEmployees = dsNorthwind.Tables["Employees"];
                
                // Initialize the Employees DataSet
                //
                if (null == dtEmployees) {
                    daEmployees.Fill(dsNorthwind, "Employees");
                    dtEmployees = dsNorthwind.Tables["Employees"];
                    
                    // Binds the database values to the controls
                    //
                    comboBoxEmployees.DataSource = dtEmployees;
                    comboBoxEmployees.DisplayMember = "Name";
                    comboBoxEmployees.ValueMember = "EmployeeID";
                    textBoxEmployeeID.DataBindings.Add("Text", dtEmployees, "EmployeeID");
                    textBoxAddress.DataBindings.Add("Text", dtEmployees, "Address");
                    textBoxCity.DataBindings.Add("Text", dtEmployees, "City");
                    textBoxRegion.DataBindings.Add("Text", dtEmployees, "Region");
                    textBoxPostalCode.DataBindings.Add("Text", dtEmployees, "PostalCode");
                    textBoxHomePhone.DataBindings.Add("Text", dtEmployees, "HomePhone");
                    textBoxTitle.DataBindings.Add("Text", dtEmployees, "Title");
                    textBoxHireDate.DataBindings.Add("Text", dtEmployees, "HireDate");
                }
                // Refresh the Employees DataSet
                //
                else {
                    dtEmployees.Clear();
                    daEmployees.Fill(dsNorthwind, "Employees");
                }
            }
            catch(SqlCeException e) {
                // Error handling mechanism
                //
                System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.Default;
                NorthwindData.ShowErrors(e);
                this.buttonSave.Enabled = false;

                return;
            }
            catch(Exception e) {
                // Error handling mechanism
                //
                System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.Default;
                MessageBox.Show(e.Message, "Northwind");
                this.buttonSave.Enabled = false;

                return;
            }

            System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.Default;

            this.buttonSave.Enabled = true;
        }

        // Save changes made to Employee records
        //
        private void buttonSave_Click(object sender, System.EventArgs e) 
        {
            DataSet dsNorthwind = NorthwindData.GetInstance().NorthwindDataSet;
            int position = BindingContext[dsNorthwind.Tables["Employees"]].Position;
            dsNorthwind.Tables["Employees"].Rows[position].EndEdit();

            if (MessageBox.Show("Are you sure you want to save? Pressing No will discard all changes.", "Northwind", System.Windows.Forms.MessageBoxButtons.YesNo, System.Windows.Forms.MessageBoxIcon.Asterisk, System.Windows.Forms.MessageBoxDefaultButton.Button1) == System.Windows.Forms.DialogResult.Yes) {
                try {
                    daEmployees.Update(dsNorthwind, "Employees");
                    dsNorthwind.AcceptChanges();
                }
                catch(SqlCeException err) {
                    // Error handling mechanism
                    //
                    NorthwindData.ShowErrors(err);
                }
                catch(Exception err) {
                    // Error handling mechanism
                    //
                    MessageBox.Show(err.Message, "Northwind");
                }
            }
            else {
                try {
                    dsNorthwind.RejectChanges();
                }
                catch(SqlCeException err) {
                    // Error handling mechanism
                    //
                    NorthwindData.ShowErrors(err);
                }
                catch(Exception err) {
                    // Error handling mechanism
                    //
                    MessageBox.Show(err.Message, "Northwind");
                }
            }
        }
    }
}