如何根據ErrorMessage（）方法更改Gridview的文本顏色？

Question

我有這些代碼 在我的CS文件：

//A method to display errors in the gridview 
    private string ErrorMessage(string input) 

     { 
      { 
       //if there are null values, error message will be displayed. 
       if (!string.IsNullOrEmpty(input)) 
        return input; 

      } 
      return "No value entered";// I am supposed to change this to red colour 


     } 

    public System.Drawing.Color InStockColor(string inStock) 
    { 
     return System.Drawing.Color.Red; 
    } 




// to read all lines of the posted csv file and put the lines in the grid view 
     var data = File.ReadAllLines(Server.MapPath(FilePath)) 
      // to split the lines according to commas 
      .Select(line => line.Split(',')) 

      .Select(columns => new { A = ErrorMessage(columns[0]), B = ErrorMessage(columns[1]), C = ErrorMessage(columns[2]), D = ErrorMessage(columns[3]), E = ErrorMessage(columns[4]), F = ErrorMessage(columns[5]), G = ErrorMessage(columns[6]), H = ErrorMessage(columns[7]), I = ErrorMessage(columns[8]) }); 


     myGridView.DataSource = data; 
     myGridView.DataBind(); 



<asp:GridView ID="myGridView" runat="server" CellPadding="4" 
    EnableModelValidation="True" ForeColor="#333333" GridLines="None" 
    Width="414px" align="center"> 
    <AlternatingRowStyle BackColor="White" /> 

    <EditRowStyle BackColor="#2461BF" /> 
    <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" /> 
    <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" /> 
    <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" /> 
    <RowStyle BackColor="#EFF3FB" /> 
    <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" /> 

</asp:GridView> 

到目前爲止，我已經建立，這將改變文字顏色的方法。現在，我該如何實現這個方法？應該更改爲紅色的文本是「沒有輸入值！」

Answer 1

這就是我將如何解決問題！

using System.Drawing; 

private string ErrorMessage(string input, int rowNr, int colNr)   
{    
    if (!string.IsNullOrEmpty(input)) 
     return input; 

    myGridView.Rows[rowNr].Cells[colNr].ForeColor = Color.Red; 
    return "No value entered"; 
} 

另一種方法是添加HTML標籤這樣的...

using System.Drawing; 

private string ErrorMessage(string input, int rowNr, int colNr)   
{    
    if (!string.IsNullOrEmpty(input)) 
     return input; 
    return "<font color='Red'>" + "No value entered" + "</font>"; 
} 

，但我不建議標籤，因爲<font>已被棄用，你居然設置單元格中的文本值html代碼。

希望這會有所幫助！

編輯：

能否請您解釋一下這段代碼...馬貝提供一些背景 什麼樣的語法是什麼？

你能解釋一下.Select（...）命令是如何工作的嗎？他們做什麼？

// to read all lines of the posted csv file and put the lines in the grid view 
     var data = File.ReadAllLines(Server.MapPath(FilePath)) 
      // to split the lines according to commas 
      .Select(line => line.Split(',')) 

      .Select(columns => new { A = ErrorMessage(columns[0]), B = ErrorMessage(columns[1]), C = ErrorMessage(columns[2]), D = ErrorMessage(columns[3]), E = ErrorMessage(columns[4]), F = ErrorMessage(columns[5]), G = ErrorMessage(columns[6]), H = ErrorMessage(columns[7]), I = ErrorMessage(columns[8]) }); 


     myGridView.DataSource = data; 
     myGridView.DataBind();