[Implementing the ASP. Net Control as day17] Set attributes include members of different types

We know that columns set attributes in the gridview can contain fields of different types, such as boundfield, checkboxfield, hyperlinkfield... and other fields of different types. If we want the tool column to contain more than buttons and other child controls of different types, what should we do? In this article, the tbtoolbar control in the previous article is used as a case, so that the items set attributes can be added to different child controls such as button, Textbox, label.

Download program code: ASP. NET Server Control-day17.rar

1. Set members of different types

Our requirement is that the tool columns can be added with three sub-controls: button, Textbox, and label. Therefore, we inherit the original tbtoolbaritem (only the enabled attribute is retained ), three categories are added: tbtoolbarbutton, tbtoolbartextbox, and tbtoolbarlabel.

 

These new member classes are inherited to tbtoolbaritem. Therefore, when you manually enter items members in the aspx program code, these defined member types are listed.

 

2. Create child controls for members of different types of Sets

Because the members of the items attribute have different types, We need to rewrite the rendercontents method and determine the member type to create a child control of the corresponding type. If it is tbtoolbarbutton, a button control is created. If it is tbtoolbartextbox, A Textbox Control is created. If it is tbtoolbarlabel, a label control is created. The control created by tbtoolbarbutton is tbbutton. This control is a button control with inquiry information that we implement in [ASP. NET control implement day3] extend existing Server control function.

        ''' <summary>

''' Override the rendercontents method.

        ''' </summary>

        Protected Overrides Sub RenderContents(ByVal writer As System.Web.UI.HtmlTextWriter)

            Dim oItem As TBToolbarItem

            Dim oControl As Control

            For Each oItem In Me.Items

                If TypeOf oItem Is TBToolbarButton Then

'Create a Button Control Handler

                    oControl = CreateToolbarButton(CType(oItem, TBToolbarButton))

                ElseIf TypeOf oItem Is TBToolbarTextbox Then

'Create a Textbox Control struct

                    oControl = CreateToolbarTextbox(CType(oItem, TBToolbarTextbox))

                Else

'Create a label control role

                    oControl = CreateToolbarLabel(CType(oItem, TBToolbarLabel))

                End If

                Me.Controls.Add(oControl)

            Next

            MyBase.RenderContents(writer)

        End Sub

        ''' <summary>

'''Create a tool column and press confirm.

        ''' </summary>

        Private Function CreateToolbarButton(ByVal Item As TBToolbarButton) As Control

            Dim oButton As TBButton

            Dim sScript As String

            oButton = New TBButton()

            oButton.Text = Item.Text

            oButton.Enabled = Item.Enabled

            oButton.ID = Item.Key

            oButton.ConfirmMessage = Item.ConfirmMessage

            sScript = Me.Page.ClientScript.GetPostBackEventReference(Me, Item.Key)

            oButton.OnClientClick = sScript

            Return oButton

        End Function

        ''' <summary>

''' Create a text box for the tool column.

        ''' </summary>

        Private Function CreateToolbarTextbox(ByVal Item As TBToolbarTextbox) As Control

            Dim oTextBox As TextBox

            oTextBox = New TextBox

            Return oTextBox

        End Function

        ''' <summary>

''' Create a tool column label.

        ''' </summary>

        Private Function CreateToolbarLabel(ByVal Item As TBToolbarLabel) As Control

            Dim oLabel As Label

            oLabel = New Label()

            oLabel.Text = Item.Text

            Return oLabel

        End Function

 

When we manually enter different types of members in the aspx program code, the tbtoolbar control will display the corresponding child control.

 

Iii. execution procedure

Execute the program and you will see the rendered tool column in the browser. When you press "delete", the inquiry message we defined will also appear.

 

The output HTML code is as follows:

<span id="TBToolbar1">

<Input type = "Submit" name = "tbtoolbar1 $ Add" value = "add" onclick = "_ dopostback ('tbtoolbar1', 'add '); "id =" tbtoolbartailadd "/>

<Input type = "Submit" name = "tbtoolbar1 $ edit" value = "modify" onclick = "_ dopostback ('tbtoolbar1', 'edit '); "id =" tbtoolbar#edit "/>

<Input type = "Submit" name = "tbtoolbar1 $ Delete" value = "Divide division" onclick = "If (confirm ('Are you sure you want to divide? ') = False) {return false; }__ dopostback ('tbtoolbar1', 'delete'); "id =" tbtoolbar1_delete "/>

<Span> keywords </span>

<input name="TBToolbar1$ctl01" type="text" />

<Input type = "Submit" name = "tbtoolbar1 $ search" value = "search criteria" onclick = "_ dopostback ('tbtoolbar1', 'search '); "id =" tbtoolbarshortsearch "/>

</span>

 

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