我在 ListView 的每个项目中显示一个图像。我希望图像在一个框中水平和垂直居中。我的代码如下:
Protected Sub MembersLV_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ListViewItemEventArgs) Handles MembersLV.ItemDataBound
If e.Item.ItemType = ListViewItemType.DataItem Then
Dim LogoImage As System.Web.UI.WebControls.Image = e.Item.FindControl("LogoImage")
Dim LogoLink As HtmlControl = e.Item.FindControl("LogoLink")
Dim di As ListViewDataItem = DirectCast(e.Item, ListViewDataItem)
Dim ImageFileName As String = di.DataItem("FileName")
Dim FilePath As String = String.Format("/Uploads/MembersDirectory/w125h85/{0}", ImageFileName)
If File.Exists(Server.MapPath(FilePath)) Then
LogoImage.ImageUrl = FilePath
Dim BoxHeight As Integer = 101
Dim BoxWidth As Integer = 138
Dim B As New Bitmap(Server.MapPath(FilePath))
Dim BHeight As Integer = B.Height
Dim BWidth As Integer = B.Width
Dim PaddingTop As Integer = Math.Ceiling(BoxHeight - BHeight) / 2
Dim PaddingLeft As Integer = Math.Ceiling(BoxWidth - BWidth) / 2
LogoLink.Attributes.Add("style", String.Format("padding: {0} 0 0 {1};", PaddingTop, PaddingLeft))
End If
End If
End Sub
我只需计算图像顶部和左侧所需的填充量以使其居中,然后将该填充作为样式属性添加到周围的标记中。
aspx文件中的代码如下:
<a href='<%#Eval("Website") %>' id="LogoLink" runat="server">
<asp:Image ID="LogoImage" runat="server" AlternateText='<%#Eval("Name") %>' />
</a>
当我运行此代码时,没有对<a>
标签应用任何填充。PaddingTop
所以我做了一个快速检查,以确保PaddingLeft
使用Response.Write
. 奇怪的是,我这次运行的时候,style属性正确出现了!但是没有Response.Write
,就没有 style 属性。
我究竟做错了什么?