The practice of a general DataGridTableStyle

The DataGrid a generic DataGridTableStyle approach



Ah, these two days like to write "universal" things.

This class, you can achieve adaptive column width, read-only, Time division display, events, arbitrary placement, click the background color settings, and so on, easy to operate. It's just a matter of time (going out tomorrow), it's not perfect today. For reference only, you can add something else. The following is only a list of code, not clear of their own trial to check the information on the line.



Public Class TableStyle



Private M_datagridtablestyle as DataGridTableStyle

Private m_DataGrid as DataGrid

Private m_datatable as DataTable

'//Add event handling, here only consider DataGridTextBoxColumn double-click event

Public Delegate Sub ClickEventHandler (ByVal sender as Object, ByVal e as System.EventArgs)

Public Event Gridtextboxdoubleclickevent as ClickEventHandler

Public Sub Gridtextbox_doubleclick (ByVal sender as Object, ByVal e as System.EventArgs)

RaiseEvent gridtextboxdoubleclickevent (sender, E)

End Sub

'//Set DataGrid

Public Property [DataGrid] () as DataGrid

Get

Return m_DataGrid

End Get

Set (ByVal Value as DataGrid)

m_DataGrid = Value

End Set

End Property

'//Return template

Public ReadOnly Property [DataGridTableStyle] () as DataGridTableStyle

Get

Return M_datagridtablestyle

End Get

End Property

'//initialization

Public Sub Initialize ()

'//Judge Mdatagrid data Source Type

'//If the binding is a dataset or DataViewManager or no data source is bound, exit,

If TypeOf M_datagrid.datasource is System.Data.DataSet OrElse _

TypeOf M_datagrid.datasource is System.Data.DataViewManager OrElse _

M_datagrid.datasource is nothing Then Exit Sub



'//below consider two data sources, one is DataView, one is DataTable

If TypeOf M_datagrid.datasource is System.Data.DataView Then

m_datatable = CType (M_datagrid.datasource, DataView). Table

Else

m_datatable = CType (M_datagrid.datasource, DataTable)

End If



M_datagridtablestyle = New DataGridTableStyle

M_datagridtablestyle.mappingname = M_datatable.tablename

'//Add ColumnStyle

Dim Mdatacolumn as DataColumn

Dim Mcolumnstyle as DataGridColumnStyle

For each mdatacolumn in M_datatable.columns



Select Case MDataColumn.DataType.Name

Case "Boolean"

Mcolumnstyle = New DataGridBoolColumn

Case Else

Mcolumnstyle = New DataGridTextBoxColumn

AddHandler CType (Mcolumnstyle, DataGridTextBoxColumn). Textbox.doubleclick, AddressOf Gridtextbox_doubleclick

End Select



'//Bind to column of DataTable

With Mcolumnstyle

. MappingName = Mdatacolumn.columnname

. HeaderText = Mdatacolumn.columnname

End With



'//Join to DataGridTableStyle

M_DATAGRIDTABLESTYLE.GRIDCOLUMNSTYLES.ADD (Mcolumnstyle)

Next



'//Bind the DataGridTableStyle to the DataGrid

M_DataGrid.TableStyles.Clear ()

M_DATAGRID.TABLESTYLES.ADD (M_datagridtablestyle)

End Sub

'//Adaptive width

Public Sub Autoextend ()

If M_datagridtablestyle is nothing Then Exit Sub

' Take the maximum number of bytes in each field, including field names and values

Dim Mrow as DataRow

Dim Mcolumn as DataColumn

For each mcolumn in M_datatable.columns

M_datagridtablestyle.gridcolumnstyles (Mcolumn.columnname). Width = getcolumnmaxwidth (0, Mcolumn.columnname)

Next



For each mrow in M_datatable.rows

For each mcolumn in M_datatable.columns

If not IsDBNull (Mrow (mcolumn.columnname)) Then

M_datagridtablestyle.gridcolumnstyles (Mcolumn.columnname). Width = _

Getcolumnmaxwidth (M_datagridtablestyle.gridcolumnstyles (mcolumn.columnname). Width, Mrow (mcolumn.columnname). ToString)

End If

Next

Next



' Refer to the graphics of the DataGrid to assign the actual width

For each mcolumnstyle as DataGridColumnStyle in M_datagridtablestyle.gridcolumnstyles

Mcolumnstyle.width = ColumnWidth (mcolumnstyle.width)

Next

End Sub



Private Function getcolumnmaxwidth (ByVal maxwidth As Integer, ByVal mstring as String) As Integer

Dim Mlength as Integer

Mlength = System.Text.Encoding.Default.GetBytes (mstring). Length ()

If MaxWidth < Mlength Then

Return mlength

Else

Return MaxWidth

End If

End Function

Private Function ColumnWidth (ByVal maxwidth As Integer) As Integer

Dim mgraphics as Graphics = M_datagrid.creategraphics

Dim Mcolwidth as Single

Mcolwidth = mgraphics.measurestring (New String (CType ("A", Char), maxwidth), M_datagrid.font). Width + 2

Return CType (Mcolwidth, Integer)

End Function

'//Add a column after a column

Public Sub AddColumn (ByVal poscolumnname As String, ByVal ColumnName as String)

If M_datagridtablestyle is nothing Then Exit Sub

If not M_DataTable.Columns.Contains (poscolumnname) Then Exit Sub

If m_DataTable.Columns.Contains (ColumnName) Then Exit Sub

Dim Tmpstyle as New DataGridTableStyle

For each mcolumnstyle as DataGridColumnStyle in M_datagridtablestyle.gridcolumnstyles

TMPSTYLE.GRIDCOLUMNSTYLES.ADD (Mcolumnstyle)

If mColumnStyle.HeaderText.Equals (poscolumnname) Then

Dim Tmptextcolumn as New datagridtextboxcolumn

M_DATATABLE.COLUMNS.ADD (ColumnName)

Tmptextcolumn.headertext = ColumnName

Tmptextcolumn.mappingname = ColumnName

TMPSTYLE.GRIDCOLUMNSTYLES.ADD (Tmptextcolumn)

End If

Next

M_DataGrid.TableStyles.Clear ()

Tmpstyle.mappingname = M_datagridtablestyle.mappingname

M_datagridtablestyle = Tmpstyle

M_DATAGRID.TABLESTYLES.ADD (M_datagridtablestyle)

End Sub

'//does not show null

Public WriteOnly Property Notshownull () as Boolean

Set (ByVal Value as Boolean)

For each mcolumnstyle as DataGridColumnStyle in M_datagridtablestyle.gridcolumnstyles

If Value Then

Mcolumnstyle.nulltext = ""

Else

Mcolumnstyle.nulltext = "(NULL)"

End If

Next

End Set

End Property

'//If is the date type, displays the time

Public WriteOnly Property Showtimeformat () as Boolean

Set (ByVal Value as Boolean)

For each mcolumnstyle as DataGridColumnStyle in M_datagridtablestyle.gridcolumnstyles

If Not mcolumnstyle.mappingname = "" AndAlso m_datatable.columns (mcolumnstyle.mappingname). DataType.Name.IndexOf ("Date") <>-1 Then

If Value Then

CType (Mcolumnstyle, DataGridTextBoxColumn). Format = "Yyyy-mm-dd hh:mm:ss"

Else

CType (Mcolumnstyle, DataGridTextBoxColumn). Format = "Yyyy-mm-dd"

End If

End If

Next

End Set

End Property

' Individual edits, except logical types

Public ReadOnly Property Textcolumnstyle (ByVal ColumnName as String) as DataGridTextBoxColumn

Get

If not M_datatable.columns (ColumnName) is no AndAlso not M_datatable.columns (ColumnName). DataType.Name.Equals ("Boolean") Then

Return CType (M_datagridtablestyle.gridcolumnstyles (ColumnName), DataGridTextBoxColumn)

Else

Return Nothing

End If

End Get

End Property

End Class



' Test

Dim Mytablestyle as New TableStyle

Private Sub button1_click (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles Button1.Click

Dim DS as New DataSet

Me.SqlConnection1.Open ()

Me.SqlDataAdapter1.Fill (DS)

Me.SqlConnection1.Close ()

Me.DataGrid1.DataSource = ds. Tables (0)
AddHandler Mytablestyle.gridtextboxdoubleclickevent, AddressOf


End Sub

Private Sub button2_click (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles Button2.click

With Mytablestyle

. DataGrid = Me.datagrid1

. Initialize ()

End With

Me.datagridtextcolumn_doubleclick

End Sub

Private Sub button3_click (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles Button3.click

Mytablestyle.notshownull = True

Mytablestyle.showtimeformat = True

End Sub



Private Sub button4_click (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles Button4.click

Mytablestyle.notshownull = False

Mytablestyle.showtimeformat = False

End Sub

Private Sub button5_click (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles Button5.click

MyTableStyle.DataGridTableStyle.GridColumnStyles (2). ReadOnly = True

End Sub



Private Sub button6_click (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles Button6.click

Mytablestyle.addcolumn ("name", "Hello")

Mytablestyle.autoextend ()

End Sub



Private Sub Button7_click (ByVal sender as System.Object, ByVal e as System.EventArgs) Handles Button7.click

Mytablestyle.textcolumnstyle ("name"). Width=0

End Sub



Private Sub Datagridtextcolumn_doubleclick (ByVal sender as Object, ByVal e as System.EventArgs)

Dim Mtextbox as TextBox = CType (sender, TextBox)

Mtextbox.backcolor = System.Drawing.Color.Blue

MsgBox (Mtextbox.text)

End Sub