WinForm常用代码

//ToolStripSplitButton是标准按钮和下拉按钮的组合，各自工作，但有联系，感觉上后者是没有向下箭头ToolStripDropDownButton；
ToolStripDropDownButton只含有一个按钮，可以选择有没有向下箭头的标志，单击时显示关联的 ToolStripDropDown 的控件。两者均可改变箭头标志在做还是在右。

//VS自带双缓冲
this.SetStyle(ControlStyles.UserPaint |
 ControlStyles.AllPaintingInWmPaint |
ControlStyles.OptimizedDoubleBuffer, true);

//控件双缓冲
Control.DoubleBuffered=true; //attribute modfied by Protected

//手工双缓冲
Bitmap bmp = new Bitmap(600, 600);
Graphics g = Graphics.FromImage(bmp);
g.DrawLine();
this.CreateGraphics().DrawImage(bmp, 0, 0);//这句是关键，不能在OnPaint里画BitBmp在这里调Invalidate

Invalidate(Rectangle)//规定区域重绘，解决闪烁的另一种方法

ComboBox ComboBox1 = (ComboBox) sender;
(Sender as SomeObject).Method()

this.label1.Font = new System.Drawing.Font("微软雅黑", 72F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
this.label1.Font = new Font("微软雅黑", fontSize);

//自定义控件背景透明
SetStyle(ControlStyles.UserPaint, true);
SetStyle(ControlStyles.SupportsTransparentBackColor, true);
this.BackColor = Color.Transparent;

//获得程序集
System.Reflection.Assembly assem = System.Reflection.Assembly.GetExecutingAssembly();

//点移位
Point.Offset(Point);
Point.Offset(int,int);

Rectangle.Contains(Point);

//截获标题栏消息，自画标题栏
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之间的代码不会引起Parent Control的重绘
Control.AddRange(new Control[]{});//添加多个控件
Control.ResumeLayout;// 在它和SuspendLayout之间的代码不会引起Parent Control的重绘

Button[] buttons = new Button[] {};//大胆地设类数组吧~
Button.SetBounds(int,int,int,int);//设置Button的左、右、宽、高；

//应该尽可能地用Anchor、Dock，特殊情况下用Layout事件

Form.MdiParent=(Form);//设置MDI父窗口

//Active事件里this.Hide()是正道

Form.Show();
Form.Text=”Mytext”;//这两句的顺序不能

//static不能修饰临时变量，一般用来修饰类变量（不是类的对象实例变量！！！）

Form.MdiParent = this;
Form.TopLevel = true;
Form.IsMdiContainer= true;

Form. ActivateMdiChild

//sqlconnection连接字符串
@"Data Source= .\SQLEXPRESS;AttachDBFilename=C:\..\*.MDF;Integrated Security=True;User Instance=True"))

//sqlconnection连接的基本步骤
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添加项

//创建DataSet中的记录
DataRow row = DataSet.Tables[0].NewRow();
row["**"] =***;
dataset.Tables[0].Rows.Add(row);

//更新DataSet
DataRow row=DataSet.Table[0].Rows[index];
row[“***”]=***;

//删除DataSet中的记录
DataSet.Tables[0].Rows.Remove(DataSet.Table[0].Rows[index]);

//DataRow.Delete()和DataSet.Tables[0].Rows.Remove()不一样,后者是从DataSet中彻底删除
DataRow row=DataSet.Table[0].Rows[index];
row[“***”]=***;

row.delete();
TYPE varable=row[“***”,DataRowVersion.Original]

// DataRow的完整访问方式和DataRow.RowState
Switch (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["***"]
}

//获取部分特定状态的数据集
DataTable modifiedTable = DataSet.Tables[0].GetChanges(DataRowState.Added| DataRowState.Modified| DataRowState.Deleted);

//创建数据库查询连接适配器的几种方式
SqlDataAdapter  adapter = new SqlDataAdapter("select * from TABLENAME", SqlConnection); //最简单

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);

//万能的数据集更新器SqlCommandBuilder
SqlDataAdapter adapter = new SqlDataAdapter("select * from TABLENAME ", SqlConnection);

new SqlCommandBuilder(adapter);

try
{
adapter.Update(modifiedDataSet);
PoulateListBox();
}
catch (System.Exception ex)
{
}

//多表数据集建议分别创建适配器

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”);

//创建DataSet自带约束
UniqueConstraint constrint = new UniqueConstraint(DataTable.Columns["***"]);//唯一性约束
DataTable.Constraints.Add(constrint);
//外键约束：ForeignKeyConstraint

//关系基于两张表的两个列上，添加于两张表共属的数据集，并且自动生成分别在两个表上生成UniqueConstraint 和ForeignKeyConstraint
DataRelation relation = new DataRelation("CustomersOrders", DataTable.Columns["***"], DataTable.Columns["***"]);
dataset.Relations.Add(relation);

Form.Modal//判断显示方式是模式还是非模式，模式为true，非模式为false，只有在Load事件中和之后该属性才有实际意义，在构造期间默认为false

myForm.Control1.Text=”Data put in by a user”;//这样不好,封装性不强不易维护更新，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()只是获取对话框结果的快捷方式，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);

/*
对于每个关联的 SqlConnection，一次只能打开一个 SqlDataReader
SqlConnection 与 SqlDataAdapter 和 SqlCommand 一起使用，可以在连接 Microsoft SQL Server 数据库时提高性能。
对于所有第三方 SQL 服务器产品以及其他支持 OLE DB 的数据源，请使用 OleDbConnection。
SqlConnection 超出范围，则不会将其关闭。因此，必须通过调用 Close 或 Dispose 显式关闭该连接。最好在using 块内部打开连接。
连接自字符串关键字不区分大小写，并将忽略键/值对之间的空格。 不过，根据数据源的不同，值可能是区分大小写的。 任何包含分号、单引号或双引号的值必须用双引号引起来。
*/

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不需要担心分号、单引号或双引号的转义问题
Console.WriteLine(builder.ConnectionString);

//打开数据库的某个古老方法
SqlConnection mc=new SqlConnection();
mc.ConnectionString=”/*…*/”;
mc.Open();

//有关SqlCommand, SqlDataReader的基本使用
SqlCommand scm=SqlConnection.CreateCommand();
scm.CommandText=”select */*…*/”;
SqlDataReader sdr=scm.ExecuteReader();
sdr.Read();
//…
sdr.close();

//以ToolStrip为例绘制简便背景
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);

//获取Color的几种方式
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为全透明，255为不透明，

/*

如果安装时，改了实例名，也就是命名实例，那么客户端在连接时，要使用机器名加实例名来进行标识：计算机名\实例名。

*/

//This table shows all connection string properties for the ADO.NET SqlConnection object. Most of the properties are also used in ADO. All properties and descriptions is from msdn.

Name	Default	Description
Application Name		The name of the application, or '.Net SqlClient Data Provider' if no application name is provided.
AttachDBFilename -or- extended properties -or- Initial File Name		The name of the primary file, including the full path name, of an attachable database. The database name must be specified with the keyword 'database'.
Connect Timeout -or- Connection Timeout	15	The length of time (in seconds) to wait for a connection to the server before terminating the attempt and generating an error.
Connection Lifetime	0	When a connection is returned to the pool, its creation time is compared with the current time, and the connection is destroyed if that time span (in seconds) exceeds the value specified by connection lifetime. Useful in clustered configurations to force load balancing between a running server and a server just brought on-line.
Connection Reset	'true'	Determines whether the database connection is reset when being removed from the pool. Setting to 'false' avoids making an additional server round-trip when obtaining a connection, but the programmer must be aware that the connection state is not being reset.
Current Language		The SQL Server Language record name.
Data Source -or- Server -or- Address -or- Addr -or- Network Address		The name or network address of the instance of SQL Server to which to connect.
Enlist	'true'	When true, the pooler automatically enlists the connection in the creation thread's current transaction context.
Initial Catalog -or- Database		The name of the database.
Integrated Security -or- Trusted_Connection	'false'	Whether the connection is to be a secure connection or not. Recognized values are 'true', 'false', and 'sspi', which is equivalent to 'true'.
Max Pool Size	100	The maximum number of connections allowed in the pool.
Min Pool Size	0	The minimum number of connections allowed in the pool.
Network Library -or- Net	'dbmssocn'	The network library used to establish a connection to an instance of SQL Server. Supported values include dbnmpntw (Named Pipes), dbmsrpcn (Multiprotocol), dbmsadsn (Apple Talk), dbmsgnet (VIA), dbmsipcn (Shared Memory) and dbmsspxn (IPX/SPX), and dbmssocn (TCP/IP). The corresponding network DLL must be installed on the system to which you connect. If you do not specify a network and you use a local server (for example, "." or "(local)"), shared memory is used.
Packet Size	8192	Size in bytes of the network packets used to communicate with an instance of SQL Server.
Password -or- Pwd		The password for the SQL Server account logging on.
Persist Security Info	'false'	When set to 'false', security-sensitive information, such as the password, is not returned as part of the connection if the connection is open or has ever been in an open state. Resetting the connection string resets all connection string values including the password.
Pooling	'true'	When true, the SQLConnection object is drawn from the appropriate pool, or if necessary, is created and added to the appropriate pool.
User ID		The SQL Server login account.
Workstation ID	the local computer name	The name of the workstation connecting to SQL Server.