GridView即使在数据绑定后也不会显示

Question

我在我的页面上有一个GridView，我想将数据绑定到数据，并在显示GridView之前进行一些排序，但没有显示任何内容。以下是我的代码：

Dim dt As New DataTable 
    Dim dr As DataRow 

    ' define the table's schema 

    dt.Columns.Add(New DataColumn("PP", GetType(String))) 
    dt.Columns.Add(New DataColumn("-", GetType(String))) 
    dt.Columns.Add(New DataColumn("Distance", GetType(String))) 


    Dim i As Integer = 0 


    ' Now Create a loop that Add data into datagridview and sort by shortest distance 

    For Each r As System.Guid In arrid 
     dr = dt.NewRow() 
     dr("PP") = ResolveUrl(arrpic(i)) 
     dr("-") = Arrnames(i).ToString & " (" & arrage(i) & ")" & vbCrLf & arrgender(i) & " from " & arrlocation(i) & vbCrLf & arrcomments(i) 
     dr("Distance") = arrdistance(i) 

     i = +1 
    Next 

    GridView1.DataSource = dt.DataSet 
    GridView1.DataBind() 
    'SortDirection data by shortest distance 
    'GridView1.Sort("Distance", SortDirection.Ascending) 

Answer 1

GridView未显示，因为它是空的。

你还没有加入新行到DataTable，因此要么使用table.Rows.Add(newRow)或table.Rows.Add()代替它返回已添加（空）行：

For Each r As System.Guid In arrid 
    Dim dr = dt.NewRow() ' empty row not added yet 
    dr("PP") = ResolveUrl(arrpic(i)) 
    dr("-") = Arrnames(i).ToString & " (" & arrage(i) & ")" & vbCrLf & arrgender(i) & " from " & arrlocation(i) & vbCrLf & arrcomments(i) 
    dr("Distance") = arrdistance(i) 
    dt.Rows.Add(dr) ' now added 
    i = +1 
Next 

或

For Each r As System.Guid In arrid 
    Dim dr = dt.Rows.Add() ' empty row now already added 
    dr("PP") = ResolveUrl(arrpic(i)) 
    dr("-") = Arrnames(i).ToString & " (" & arrage(i) & ")" & vbCrLf & arrgender(i) & " from " & arrlocation(i) & vbCrLf & arrcomments(i) 
    dr("Distance") = arrdistance(i) 
    i = +1 
Next 

我喜欢第二种方法，如果可能的话，它保存一行，并防止这样的问题。