//ToolStripSplitButton是標準按鈕和下拉按鈕的組合，各自工作，但有聯系，感覺上后者是沒有向下箭頭ToolStripDropDownButton；
ToolStripDropDownButton只含有一個按鈕，可以選擇有沒有向下箭頭的標志，單擊時顯示關聯的 ToolStripDropDown 的控件。兩者均可改變箭頭標志在做還是在右。//VS自帶雙緩沖this.SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint |ControlStyles.OptimizedDoubleBuffer, true);//控件雙緩沖Control.DoubleBuffered=true; //attribute modfied by PRotected//手工雙緩沖Bitmap bmp = new Bitmap(600, 600);Graphics g = Graphics.FromImage(bmp);g.DrawLine();this.CreateGraphics().DrawImage(bmp, 0, 0);//這句是關鍵，不能?在OnPaint里畫BitBmp在這里調InvalidateInvalidate(Rectangle)//規定區域重繪，解決閃爍的另一種方法ComboBox ComboBox1 = (ComboBox) sender;(Sender as SomeObject).Method()this.label1.Font = new System.Drawing.Font("微軟雅黑", 72F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));this.label1.Font = new Font("微軟雅黑", fontSize);//自定義控件背景透明SetStyle(ControlStyles.UserPaint, true);SetStyle(ControlStyles.SupportsTransparentBackColor, true);this.BackColor = Color.Transparent;//獲得程序集System.Reflection.Assembly assem = System.Reflection.Assembly.GetExecutingAssembly();//點移位Point.Offset(Point);Point.Offset(int,int);Rectangle.Contains(Point);//截獲標題欄消息，自畫標題欄using System.Runtime.InteropServices;using System.Drawing.Drawing2D;[DllImport("user32.dll")]private static extern IntPtr GetWindowDC(IntPtr hWnd);[DllImport("user32.dll")]private static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);private const int WM_NCPAINT = 0x0085;private const int WM_NCACTIVATE = 0x0086;private const int WM_NCLBUTTONDOWN = 0x00A1;protected override void WndProc(ref Message m){    base.WndProc(ref m);    Rectangle vRectangle = new Rectangle((Width - 75) / 2, 3, 75, 25);    switch (m.Msg)    {        case WM_NCPAINT:        case WM_NCACTIVATE:            IntPtr vHandle = GetWindowDC(m.HWnd);            Graphics vGraphics = Graphics.FromHdc(vHandle);            vGraphics.FillRectangle(new LinearGradientBrush(vRectangle,                 Color.Pink, Color.Purple, LinearGradientMode.BackwardDiagonal),                vRectangle);                        StringFormat vStringFormat = new StringFormat();            vStringFormat.Alignment = StringAlignment.Center;            vStringFormat.LineAlignment = StringAlignment.Center;            vGraphics.DrawString("About", Font, Brushes.BlanchedAlmond,                 vRectangle, vStringFormat);            vGraphics.Dispose();            ReleaseDC(m.HWnd, vHandle);            break;        case WM_NCLBUTTONDOWN:            Point vPoint = new Point((int)m.LParam);            vPoint.Offset(-Left, -Top);            if (vRectangle.Contains(vPoint))                MessageBox.Show(vPoint.ToString());            break;    }}Control.SuspendLayout;//在它和ResumeLayout之間的代碼不會引起Parent Control的重繪Control.AddRange(new Control[]{});//添加多個控件Control.ResumeLayout;// 在它和SuspendLayout之間的代碼不會引起Parent Control的重繪Button[] buttons = new Button[] {};//大膽地設類數組吧~Button.SetBounds(int,int,int,int);//設置Button的左、右、寬、高；//應該盡可能地用Anchor、Dock，特殊情況下用Layout事件Form.MdiParent=(Form);//設置MDI父窗口//Active事件里this.Hide()是正道Form.Show();Form.Text=”Mytext”;//這兩句的順序不能//static不能修飾臨時變量，一般用來修飾類變量（不是類的對象實例變量！?。。〧orm.MdiParent = this;Form.TopLevel = true;Form.IsMdiContainer= true;Form. ActivateMdiChild//sqlconnection連接字符串@"Data Source= ./SQLEXPRESS;AttachDBFilename=C:/../*.MDF;Integrated Security=True;User Instance=True"))//sqlconnection連接的基本步驟using System.Data.SqlClient;Dataset dataset = new DataSet();using (SqlConnection conn = new SqlConnection(@"Data Source= ./SQLEXPRESS;AttachDBFilename=C:/SQL Server 2000 Sample Databases/NORTHWND.MDF;Integrated Security=True;User Instance=True")){conn.Open();SqlDataAdapter adapter = new SqlDataAdapter(conn.CreateCommand());    adapter.SelectCommand.CommandText = "select * from customers";adapter.Fill(dataset);foreach (DataRow row in dataset.Tables[0].Rows){string item=row["ContactTitle"]+","+row["ContactName"];    listBox1.Items.Add(item);}}ListBox.Items.Add（new string）//ListBox添加項//創建DataSet中的記錄DataRow row = DataSet.Tables[0].NewRow();row["**"] =***;dataset.Tables[0].Rows.Add(row);//更新DataSetDataRow row=DataSet.Table[0].Rows[index];row[“***”]=***;//刪除DataSet中的記錄DataSet.Tables[0].Rows.Remove(DataSet.Table[0].Rows[index]);//DataRow.Delete()和DataSet.Tables[0].Rows.Remove()不一樣,后者是從DataSet中徹底刪除DataRow row=DataSet.Table[0].Rows[index];row[“***”]=***;row.delete();TYPE varable=row[“***”,DataRowVersion.Original]// DataRow的完整訪問方式和DataRow.RowStateSwitch (row.RowState){case DataRowState.Deleted:    	row["***", DataRowVersion.Original];    case DataRowState.Added:    	row["["***"]    case DataRowState.Modified:    	row["***", DataRowVersion.Original]       	row["***", DataRowVersion.Current]case DataRowVersion.Unchanged:    	row["***"]}//獲取部分特定狀態的數據集DataTable modifiedTable = DataSet.Tables[0].GetChanges(DataRowState.Added| DataRowState.Modified| DataRowState.Deleted);//創建數據庫查詢連接適配器的幾種方式SqlDataAdapter  adapter = new SqlDataAdapter("select * from TABLENAME", SqlConnection); //最簡單SqlDataAdapter adapter = new SqlDataAdapter(SqlConnection.CreateCommand());adapter.SelectCommand.CommandText = "select * from TABLENAME ";SqlDataAdapter  adapter = new sqldat SqlDataAdapter();adapter.SelectCommand = new SqlCommand("select * from TABLENAME ", SqlConnection);//萬能的數據集更新器SqlCommandBuilderSqlDataAdapter adapter = new SqlDataAdapter("select * from TABLENAME ", SqlConnection);new SqlCommandBuilder(adapter);try{adapter.Update(modifiedDataSet);PoulateListBox();}catch (System.Exception ex){}//多表數據集建議分別創建適配器SqlDataAdapter  adapter1 = new SqlDataAdapter("select * from TABLENAME", SqlConnection); adapter1.Fill(DataSet,”TABLENAME1”);SqlDataAdapter  adapter2 = new SqlDataAdapter("select * from TABLENAME", SqlConnection); adapter2.Fill(DataSet,”TABLENAME2”);////Make some changes to the DataSet .TABLENAME1 or DataSet .TABLENAME2//new SqlCommandBuilder(adapter1);adapter1.Update(DataSet,” TABLENAME1”);new SqlCommandBuilder(adapter2);adapter2.Update(DataSet,” TABLENAME2”);//創建DataSet自帶約束UniqueConstraint constrint = new UniqueConstraint(DataTable.Columns["***"]);//唯一性約束DataTable.Constraints.Add(constrint);//外鍵約束：ForeignKeyConstraint//關系基于兩張表的兩個列上，添加于兩張表共屬的數據集，并且自動生成分別在兩個表上生成UniqueConstraint 和ForeignKeyConstraintDataRelation relation = new DataRelation("CustomersOrders", DataTable.Columns["***"], DataTable.Columns["***"]);dataset.Relations.Add(relation);Form.Modal//判斷顯示方式是模式還是非模式，模式為true，非模式為false，只有在Load事件中和之后該屬性才有實際意義，在構造期間默認為falsemyForm.Control1.Text=”Data put in by a user”;//這樣不好,封裝性不強不易維護更新，用下面的pulbic String Control1Text{	get{		return Control1.Text;}Set{	Control1.Text;=value;}}//…myForm. Control1Text=” Data put in by a user”;//DialogResult res=ShowDialog()只是獲取對話框結果的快捷方式，完整方式如下void someButton_Click(object sender,EventArgs e){this.DialogResult=DialogResult.Retry;	this.close();}someForm=new someForm();someForm.showDialog();DialogResult ref= someForm .DialogResult;if(ref= DialogResult.Retry)//…string path =Directory.GetCurrentDirectory();System.IO.FileStream aFile = new System.IO.FileStream(path, FileMode.Open);StreamReader sr = new StreamReader(aFile, System.Text.Encoding.Default);/*對于每個關聯的 SqlConnection，一次只能打開一個 SqlDataReaderSqlConnection 與 SqlDataAdapter 和 SqlCommand 一起使用，可以在連接 Microsoft SQL Server 數據庫時提高性能。對于所有第三方 SQL 服務器產品以及其他支持 OLE DB 的數據源，請使用 OleDbConnection。SqlConnection 超出范圍，則不會將其關閉。因此，必須通過調用 Close 或 Dispose 顯式關閉該連接。最好在using 塊內部打開連接。連接自字符串關鍵字不區分大小寫，并將忽略鍵/值對之間的空格。 不過，根據數據源的不同，值可能是區分大小寫的。 任何包含分號、單引號或雙引號的值必須用雙引號引起來。*/System.Data.SqlClient.SqlConnectionStringBuilder builder =new System.Data.SqlClient.SqlConnectionStringBuilder();builder["Data Source"] = "(local)";builder["integrated Security"] = true;builder["Initial Catalog"] = "AdventureWorks;NewValue=Bad";// 使用System.Data.SqlClient.SqlConnectionStringBuilder不需要擔心分號、單引號或雙引號的轉義問題Console.WriteLine(builder.ConnectionString);//打開數據庫的某個古老方法SqlConnection mc=new SqlConnection();mc.ConnectionString=”/*…*/”;mc.Open();//有關SqlCommand, SqlDataReader的基本使用SqlCommand scm=SqlConnection.CreateCommand();scm.CommandText=”select */*…*/”;SqlDataReader sdr=scm.ExecuteReader();sdr.Read();//…sdr.close();//以ToolStrip為例繪制簡便背景e.Graphics.FillRectangle(new System.Drawing.Drawing2D.LinearGradientBrush(new System.Drawing.Point(0, toolStrip1.Height),new System.Drawing.Point(0, 0), Color.FromKnownColor(KnownColor.ControlDark), Color.FromKnownColor(KnownColor.ControlLight)), toolStrip1.ClientRectangle);//獲取Color的幾種方式Color.FromKnownColor(KnownColor.ControlLight);Color.FromArgb(int r,int g,int b);Color.FromArgb(int a,int r,int g,int b);//a表示透明度，0-255，0為全透明，255為不透明，