class1.vb

對c#初學者參考..為課題asp.net 2.0教材代碼

Imports System.ComponentModel
Imports System.Web.UI

<DefaultProperty("Text"), _
 ToolboxData("<{0}:WebCustomControl1 runat=server></{0}:WebCustomControl1>")> 
Public Class WebCustomControl1
    Inherits System.Web.UI.WebControls.WebControl

    Dim _text As String

    <Bindable(True), Category("Appearance"), Themeable(False), DefaultValue("")> _
    Property [Text]() As String
        Get
            Return _text
        End Get

        Set(ByVal Value As String)
            _text = Value
        End Set
    End Property


    Protected Overrides Sub Render(ByVal output As System.Web.UI.HtmlTextWriter)
        output.RenderBeginTag(HtmlTextWriterTag.Div)

        output.AddAttribute(HtmlTextWriterAttribute.Type, "text")
        output.AddAttribute(HtmlTextWriterAttribute.Id, Me.ClientID)
        output.AddAttribute(HtmlTextWriterAttribute.Name, Me.ClientID)
        output.AddAttribute(HtmlTextWriterAttribute.Value, Me.Text)

        output.AddAttribute("OnBlur", "ValidateText(this)")
        Me.AddAttributesToRender(output)

        output.RenderBeginTag(HtmlTextWriterTag.Input)
        output.RenderEndTag()

        output.RenderEndTag()
    End Sub

    Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
        Page.ClientScript.RegisterStartupScript(GetType(Page), _
           "ControlFocus", "document.getElementById('" & Me.ClientID & "').focus();", _
           True)

        Page.ClientScript.RegisterClientScriptBlock( _
            GetType(Page), _
            "ValidateControl", _
            "function ValidateText() {" & _
                "if (ctl.value=='') {" & _
                    "alert('Please enter a value.');ctl.focus(); }" & _
            "}", _
            True)
    End Sub


End Class