statement:
1. All code is not indicated by himself.
2, all code is commissioned in this machine
3, this post applies to beginners (I also)
4. Welcome everyone's righteous ax, providing ideas or code
5, I am striving to supplement daily (now this is not done)
6. I don't agree, please do not reprint the code written by myself.
7, everyone says do you want to have the sixth?
8. Ha, the statement is written like this, it is not serious, nor
Water like smoke 2004.7.19
[Control class]
TreeView
1. Add a Tooltip to the node (2004.7.19)
Private TMPTREENODE As Treenode
Private MtreeViewTooltip As New Tooltip
Private sub treeview1_mousemove (Byval e as system.windows.forms.mouseeventargs) Handles TreeView1.mousemove
Dim Mnode as Treenode
Mnode = me.treeview1.getnodeat (E.x, E.Y)
'There is no node
IF mnode is nothing then
MtreeViewTooltip.SetTooltip (Me.TreeView1, Nothing)
EXIT SUB
END IF
'More than the border of the current Node
If mnode.bounds.right
MtreeViewTooltip.SetTooltip (Me.TreeView1, Nothing)
EXIT SUB
END IF
'Same Node
IF mnode is tmptreenode one
EXIT SUB
END IF
MtreeViewTooltip.AutomaticDelay = 500
MtreeViewTooltip.SetTooltip (Me.TreeView1, Mnode.Text)
TMPTREENODE = Mnode
End Sub
DataGrid
1, adaptive to each column (2004.7.19)
'Define a field information class
Private class columnInfo
Public [name] AS STRING
Public [datatype] AS STRING
Public maxwidth as integer = 0
Public Sub CompareStringLength (Byval Mstring As String)
Dim MLENGTH AS INTEGER
MLENGTH = system.text.Encoding.default.getbytes (mstring) .length ()
IF MaxWidth End Sub Public Function ColumnWidth (Byval MDataGrid AS DataGrid) AS Integer DIM mgraphics as graphics = MDataGrid.creategraphics DIM MCOLWIDTH AS SINGLE McOLWIDTH = MGRAPHICS.MEASURESTRING (New String (CType ("a", char), maxwidth, mdatagrid.font) .width 2 Return CType (McOLWIDTH, INTEGER) END FUNCTION END CLASS Private Sub MakeDataGridAutoExtend (Byval MDataGrid As DataGrid) 'Judging MDATAGRID Data Source Type 'If binding is DataSet or DataViewManager or not bind any data source, exit, If TypeOf MDataGrid.DataSource IS System.Data.Dataset ORELSE _ TypeOf MDataGrid.DataSource IS System.Data.DataViewManager ORELSE _ MDataGrid.datasource is nothing kilos 'The following considerations two data sources, one is DataView, one is DATATABLE DIM DT AS DATATABLE If TypeOf MDataGrid.DataSource IS System.Data.DataView Then DT = ctype (mdatagrid.datasource, dataview) .table Else Dt = ctype (mdatagrid.datasource, dataable) END IF 'Take all field information Dim McolumnInfo (DT.Columns.count - 1) As ColumnInfo DIM I as integer = 0 DIM MCOLUMN AS Datacolumn For Each Mcolumn in Dt.columns DIM Minfo As New ColumnInfo With minfo .Name = mcolumn.columnname .DATATYPE = MCOLUMN.DATATYPE.TOSTRING .CompareStringLength (MCOLUMN.COLUMNAME) End with McolumnInfo (i) = minfo i = 1 NEXT 'Take the maximum length of each field Dim Mrow as DataRow For Each Mrow in Dt.Rows For i = 0 to dt.columns.count - 1 IF not isdbnull (Mrow (i)) THEN McolumnInfo (i) .CompareStringLength (CType (MROW (i), String) END IF NEXT NEXT 'Construction DataGridTableStyle DIM TS AS New DataGridtableStyle Ts.mappingname = dt.tablename 'map here to the table For i = 0 to dt.columns.count - 1 IF MColumnInfo (i) .DATATYPE.EQUALS ("System.Boolean") THEN 'This is a boolean field DIM BLNCOL As New DataGridBoolColumn WITH BLNCOL . Mappingname = mcolumninfo (i) .name .Headertext = McolumnInfo (i) .name .Width = mcolumninfo (i) .Columnwidth (MDataGrid) .Nulltext = "" " End with Ts.GridColumnStyles.Add (blncol) Else 'Non-boolean field DIM TXTCOL AS New DataGridTextBoxColumn WITH TXTCOL . Mappingname = mcolumnInfo (i) .name 'This map to the field. Headertext = MCOLUMNINFO (i) .name' This can be changed to the name you want to display .Width = mcolumninfo (i) .Columnwidth (MDataGrid) 'Set to 0, you can't see it. .NullText = "" 'does not display (NULL) .Readonly = false 'This can be set to read only .Format = "" "You can set the display format, and you want to display the day-time seconds. End with Ts.GridColumnStyles.Add (txtcol) END IF NEXT MDataGrid.tablestyles.clear () MDataGrid.TablesTyles.Add (TS) 'Being other functions, such as binding events, then supplement End Sub 'transfer Private sub Button2_click (byvalgend, byval e as system.eventargs) Handles Button2.click MakedataGridAutoExtend (me.datagrid1) End Sub 2, position to the designated condition line (2004.7.20) Public Function Pointto (Byval MDataGrid As DataGrid, Byval MfieldName As String, Byval MfieldValue AS String) AS Integer 'Judging the type of MDataGrid data source 'If binding is DataSet or DataViewManager or not bind any data source, exit, If TypeOf MDataGrid.DataSource IS System.Data.Dataset ORELSE _ TypeOf MDataGrid.DataSource IS System.Data.DataViewManager ORELSE _ MDataGrid.datasource is nothing kiln 'The following considerations two data sources, one is DataView, one is DATATABLE DIM DV AS DATAVIEW If TypeOf MDataGrid.DataSource IS System.Data.DataView Then DV = ctype (MDataGrid.DataSource, DataView) Else DV = ctype (mdatagrid.datasource, dataable) .defaultView END IF Dv.Sort = mfieldname DV.ApplyDefaultsort = TRUE Dim rowindex as integer = -1 Try RowIndex = DV.Find (MfieldValue) If RowIndex <> -1 Ten MDataGrid.currentrowindex = Rowindex Catch ex as systemexception MSGBOX (ex.Message) END TRY Return RowIndex END FUNCTION 2, multi-line selection process (2004.7.21) Private sub Button2_click (byvalgend, byval e as system.eventargs) Handles Button2.click Dim DM as bindingmanagerbasedm = me.bindingcontext (DS, DS.TABLES (0) .tablename) DIM I as integer Listbox2.Items.clear () For i = 0 to DM.COUNT - 1 If Me.DataGrid1.isselected (i) THEN Me.ListBox2.Items.add (DS.Tables (0) .ROWS (i) (1)) 'This i is the selected line END IF NEXT End Sub 3, display Gridcell data under the mouse in TextBox (2004.7.22) PRIVATE SUB DATAGRID1_MOUSEMOVE (Byval e as system.windows.forms.mouseeventargs) Handles DataGrid1.mousemove Dim myhit as datagrid.hittestinfo MyHit = DataGrid1.hittest (E.X, E.Y) If myhit.row = -1 oralse myhit.column = -1 Then Me.TextBox1.text = "" Else Me.TextBox1.text = Me.DataGrid1.item (MyHit.Row, myhit.column) .tostring END IF End Sub 'When Mouse quickly removes DataGrid, the above MyHit = DataGrid1.hittest (E.x, E.Y) 'Is it unable to respond in time, so add this: Private sub DataGrid1_mouseeleave (Byval e as system.eventargs) Handles DataGrid1.MouseLeave Me.TextBox1.text = "" End Sub [Data Class] DataSet 1. How to write a function in the DataSet to return the index of the current operation (2004.7.28) Private function getpos (Byval DT As DataTable) AS INTEGER Dim Mbind As BindingManagerBase Mbind = me.bindingContext (DT) Return mbind.position END FUNCTION 'transfer DIM MTABLEPOS AS INTEGER MTABLEPOS = GetPos (DS.Tables (TABLENAME)) Reader 1. According to a SQL statement and related connections, a series of tuples is queried, and these tuples are saved and returned by a two-dimensional string array (2004.7.28) Public Function SelectArray (Byval Query As String, Byval Connection As Oledb.oledbconnection) AS Array DIM MCOLS AS INTEGER Dim rowlist as new arraylist DIM MCM AS New Oledb.Oledbcommand (Query, Connection) If connection.state <> connectionState.open kilnness.Open () DIM MRD AS OLEDB.OLEDBDATAREADER = MCM.EXECUTEREADER Mcols = mrd.fieldcount While Mrd.Readdim Mrow (McOLS - 1) AS Object MRD.GetValues (MROW) Rowlist.add (MROW) End while MRD.Close () Connection.Close () Return Rowlist.toArray END FUNCTION
