commonqueryform.cs

C#自定义查询控件

		#region Methods

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		protected override void WndProc(ref Message m)
		{
			const int WM_HOTKEY = 0x0312;

			switch( m.Msg )
			{
				case WM_HOTKEY:
					btnExecute_Click( btnExecute, new System.EventArgs() );
					break;
			}
			base.WndProc (ref m);
		}

		private void QueryForm_Load(object sender, System.EventArgs e)
		{
			this.btnAdd.Click += new EventHandler(this.SetButtonProperty);
			this.btnOr.Click += new EventHandler(this.SetButtonProperty);
			this.btnClear.Click += new EventHandler(this.SetButtonProperty);

			foreach(Item i in query.Items)
				cmbCondition.Items.Add( i.Caption );

			ltbCondition.Items.Clear();
			pnlAll.BorderStyle = query.BorderStyle;

			SetButtonStyle();

			SetCommandConnection();

			NativeWin32.RegisterHotKey( Handle, 100, NativeWin32.KeyModifiers.Control, Keys.Enter );
		}

		private void cmbCondition_SelectedValueChanged(object sender, System.EventArgs e)
		{			
			SetCurrentItem( cmbCondition.Text );

			if( -1 != currItemIndex ) 
			{
				if( query.Items[currItemIndex].IsLookup ) // Lookup
				{					
					cmbValue.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
					LoadValue();
				}
				else                                      // Normal
				{
					cmbValue.DropDownStyle = System.Windows.Forms.ComboBoxStyle.Simple;
					cmbValue.Items.Clear();
				}

				cmbValue.Text = "";
			}
		}

		private void SetButtonProperty(object sender, System.EventArgs e)
		{
			if( 0<ltbCondition.Items.Count )
			{
				btnAdd.Text = "并且(&A)";

				btnOr.Enabled = true;
				btnClear.Enabled = true;
			}
			else
			{
				btnAdd.Text = "新增(&A)";

				btnOr.Enabled = false;
				btnClear.Enabled = false;			
			}

			cmbValue.Text = "";
			isButton = true;
			pnlAll.SelectNextControl( ltbCondition, true, true, false, true );			
		}

		private void btnAdd_Click(object sender, System.EventArgs e)
		{
			string line = GetCurrentLine();
			if( null == line ) 
				return;

			string header = "    ";
			if( 0<ltbCondition.Items.Count )
				header = "AND ";
			ltbCondition.Items.Add( header + line );
		}

		private void btnOr_Click(object sender, System.EventArgs e)
		{
			string line = GetCurrentLine();
			if( null == line ) 
				return;

			string header = "OR  ";
			ltbCondition.Items.Add( header + line );
		}

		private void btnClear_Click(object sender, System.EventArgs e)
		{
			ltbCondition.Items.Clear();
		}

		private void btnCancel_Click(object sender, System.EventArgs e)
		{
			ltbCondition.Items.Clear();
			this.Hide();
		}

		private void btnExecute_Click(object sender, System.EventArgs e)
		{
			if( 0>= ltbCondition.Items.Count )
				return;

			this.Hide();
		}

		private void cmbCondition_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
		{			
			if( isButton )
			{
				isButton = !isButton;
				return;
			}

			if( System.Windows.Forms.Keys.Enter == e.KeyData && ((ComboBox)sender).Text != "" )
				pnlAll.SelectNextControl( cmbCondition, true, true, false, true );
		}

		private void cmbOperator_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
		{
			if( System.Windows.Forms.Keys.Enter == e.KeyData && ((ComboBox)sender).Text != "" )
				pnlAll.SelectNextControl( cmbOperator, true, true, false, true );
		}

		private void cmbValue_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
		{
			if( System.Windows.Forms.Keys.Enter == e.KeyData && ((ComboBox)sender).Text != "" )
				pnlButton.SelectNextControl( pnlButton, true, true, true, true );
		}

		#region Lookup
		private string SQLString()
		{
			Item it = query.Items[currItemIndex];

			return "SELECT DISTINCT " + it.Field + " FROM " + it.Database + ".dbo." + it.TableName+" (NOLOCK)";
		}

		private void LoadValue()
		{
			try
			{
				command.CommandText = SQLString();
				using(System.Data.SqlClient.SqlDataReader reader = command.ExecuteReader(System.Data.CommandBehavior.Default))
				{
					while( reader.Read() )
						cmbValue.Items.Add( reader.GetString(0) );
				}
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message.ToString());
			}
		}

		#endregion

		private void SetCommandConnection()
		{
			if( query.SqlConnectionString != null && query.SqlConnectionString != "" )
			{
				System.Data.SqlClient.SqlConnection sqlcnnt = new System.Data.SqlClient.SqlConnection(query.SqlConnectionString);
				command.Connection = sqlcnnt;
			}
			else
				command.Connection = query.SqlConnection;

			if( System.Data.ConnectionState.Closed == command.Connection.State )
				command.Connection.Open();
		}

		private void SetButtonStyle()
		{
			btnAdd.FlatStyle = query.ButtonStyle;
			btnOr.FlatStyle = query.ButtonStyle;
			btnClear.FlatStyle = query.ButtonStyle;
			btnCancel.FlatStyle = query.ButtonStyle;
			btnExecute.FlatStyle = query.ButtonStyle;			
		}

		private void SetCurrentItem(string caption)
		{
			if( "" == caption )
				currItemIndex = -1;

			currItemIndex = cmbCondition.SelectedIndex;
		}

		private string GetCurrentLine()
		{
			if( "" == cmbCondition.Text || "" == cmbOperator.Text || "" == cmbValue.Text )
				return null;

			return query.Items[currItemIndex].Alias + " " + cmbOperator.Text + " '" + cmbValue.Text + "' ";
		}

		public string Condition()
		{
			string result="";
			for(int i = 0; i<ltbCondition.Items.Count; i++)
				result +=ltbCondition.Items[i].ToString();

			return result;
		}

		#endregion

		private void QueryForm_Closed(object sender, System.EventArgs e)
		{
			ltbCondition.Items.Clear();
			NativeWin32.UnregisterHotKey( Handle, 100 );
		}

	}
	#endregion
}