我如何才能使此代碼更優化

Question

我如何優化此代碼？ 我不喜歡有案例陳述，有沒有辦法我可以改善這段代碼？

protected void ddlFilterResultBy_SelectedIndexChanged(object sender, EventArgs e)
{ 
    string selVal = ddlFilterResultBy.SelectedValue.ToString().ToLower();

    switch (selVal)
    {
        case "date":
            pnlDate.Visible = true; 
            pnlSubject.Visible = false;
            pnlofficer.Visible = false;
            pnlCIA.Visible = false;
            pnlMedia.Visible = false;
            pnlStatus.Visible = false;                    
            break;

        case "subject":
            pnlDate.Visible = false;
            pnlSubject.Visible = true;
            pnlofficer.Visible = false;
            pnlCIA.Visible = false;
            pnlMedia.Visible = false;
            pnlStatus.Visible = false;
            break;

        case "officer":
            pnlDate.Visible = false;
            pnlSubject.Visible = false;
            pnlofficer.Visible = true;
            pnlCIA.Visible = false;
            pnlMedia.Visible = false;
            pnlStatus.Visible = false;
            break;

        case "status":
            pnlDate.Visible = false;
            pnlSubject.Visible = false;
            pnlofficer.Visible = false;
            pnlCIA.Visible = false;
            pnlMedia.Visible = false;
            pnlStatus.Visible = true;
            break;

        default:
            pnlDate.Visible = false;
            pnlSubject.Visible = false;
            pnlofficer.Visible = false;
            pnlCIA.Visible = false;
            pnlMedia.Visible = false;
            pnlStatus.Visible = false;
            break;
    }
}

Answer 1

很簡單。 您只會根據case選項使一個項目可見，因此只需按如下所示設置可見性即可：

pnlDate.Visible = (selVal == "date"); 
pnlSubject.Visible = (selVal == "subject");
pnlofficer.Visible = (selVal == "officer");
pnlCIA.Visible = false;
pnlMedia.Visible = false;
pnlStatus.Visible = (selVal == "status");    

這比將所有內容都設置為visible = false;更好visible = false; 然后僅顯示您需要的項目，因為這將所有內容僅包含在實際可見性設置的6行代碼中。

Answer 2

其它的辦法：

// set everything to false   
Dictionary<string, type> d = new Dictionary<string, type>()
{
    {"date", pnlDate},
    {"subject", plnSubject},
    {"officer", plnOfficer},
    {"status", plnStatus}
};

d[selVal].Visible = true;

Answer 3

protected void ddlFilterResultBy_SelectedIndexChanged(object sender, EventArgs e)
            { 
                string selVal = ddlFilterResultBy.SelectedValue.ToString().ToLower();
                        pnlDate.Visible = false;
                        pnlSubject.Visible = false;
                        pnlofficer.Visible = false;
                        pnlCIA.Visible = false;
                        pnlMedia.Visible = false;
                        pnlStatus.Visible = false;
                switch (selVal)
                {
                    case "date":
                        pnlDate.Visible = true;                    
                        break;

                    case "subject":
                        pnlSubject.Visible = true;
                        break;

                    case "officer":
                        pnlofficer.Visible = true;
                        break; 
                    case "status":
                        pnlStatus.Visible = true;
                        break;  
                }

            }

Answer 4

您可以這樣做：

protected void ddlFilterResultBy_SelectedIndexChanged(object sender, EventArgs e) { 
  string selVal = ddlFilterResultBy.SelectedValue.ToString().ToLower();

  pnlDate.Visible = (selVal == "date");
  pnlSubject.Visible = (selVal == "subject");
  pnlofficer.Visible = (selVal == "officer");
  pnlCIA.Visible = (selVal == "cia");
  pnlMedia.Visible = (selVal == "media");
  pnlStatus.Visible = (selVal == "status");
}

或者，盡管可讀性較差，但這樣會更准確：

protected void ddlFilterResultBy_SelectedIndexChanged(object sender, EventArgs e) { 
  string selVal = ddlFilterResultBy.SelectedValue.ToString();

  pnlDate.Visible = String.Equals(selVal, "date", StringComparison.OrdinalIgnoreCase);
  pnlSubject.Visible = String.Equals(selVal, "subject", StringComparison.OrdinalIgnoreCase);
  pnlofficer.Visible = String.Equals(selVal, "officer", StringComparison.OrdinalIgnoreCase);
  pnlCIA.Visible = String.Equals(selVal, "cia", StringComparison.OrdinalIgnoreCase);
  pnlMedia.Visible = String.Equals(selVal, "media", StringComparison.OrdinalIgnoreCase);
  pnlStatus.Visible = String.Equals(selVal, "status", StringComparison.OrdinalIgnoreCase);
}

Answer 5

優化和提高可讀性之間是有區別的。 因此，我想您正在考慮提高可讀性，因為這里實際上並不需要優化。 這里沒有算法可以調整，以使它在相當長的時間內變得更快。

答案1和2將是我提高可讀性的選擇

Answer 6

我認為您需要在這里使用tabcontrol 。

如果您不喜歡這些標簽，只需隱藏它們，然后通過代碼對頁面進行索引即可。

優點是您可以在設計時編輯和查看GUI。

它將易於維護。