如何解決類值初始化每個回發

Question

我試圖寫一個計算器中計算作爲一個網站，

我設置2個變量在我的課存儲號碼，

，但每次我點擊了「 +「或」 - 「按鈕，

變量返回到初始資源。

這裏是我的代碼：

public partial class _Default : System.Web.UI.Page 
{ 
    int choice = 0; 
    Boolean caluOrNot = false; 
    double before, after; 

    protected void Page_Load(object sender, EventArgs e) 
    { 

    } 

    protected void Btn1_Click(object sender, EventArgs e) 
    { 
     if (this.caluOrNot == false) 
     { 
      if (txtResult.Text.ToString() == "0") 
      { 
       txtResult.Text = "1"; 
      } 
      else 
      { 
       txtResult.Text += "1"; 
      } 
     } 
     else 
     { 
      txtResult.Text = "1"; 
     } 
    } 

    protected void Btn2_Click(object sender, EventArgs e) 
    protected void Btn3_Click(object sender, EventArgs e) 
    protected void Btn4_Click(object sender, EventArgs e) 
    protected void Btn5_Click(object sender, EventArgs e) 
    protected void Btn6_Click(object sender, EventArgs e) 
    protected void Btn7_Click(object sender, EventArgs e)  
    protected void Btn8_Click(object sender, EventArgs e) 
    protected void Btn9_Click(object sender, EventArgs e) 
    protected void Btn0_Click(object sender, EventArgs e) 

    protected void BtnPoint_Click(object sender, EventArgs e) 
    { 
     txtResult.Text += "."; 
    } 

    protected void BtnJia_Click(object sender, EventArgs e) 
    { 
     this.choice = 1; 
     this.caluOrNot = true; 
     before = Double.Parse(txtResult.Text.ToString()); 
     txtCalu.Text = before.ToString() + "+"; 

    } 

    protected void BtnJen_Click(object sender, EventArgs e) 
    protected void BtnCheng_Click(object sender, EventArgs e) 
    protected void BtnChu_Click(object sender, EventArgs e) 

    protected void btnClear_Click(object sender, EventArgs e) 
    { 
     txtResult.Text = "0"; 
     this.choice = 0; 
    } 

    protected void btnGo_Click(object sender, EventArgs e) 
    { 
     double a; 
     switch (this.choice) 
     { 
      case 1: 
       a = before + after; 
       txtResult.Text = a.ToString(); 
       break; 
      case 2: 
       a = before - after; 
       txtResult.Text = a.ToString(); 
       break; 
      case 3: 
       a = before * after; 
       txtResult.Text = a.ToString(); 
       break; 
      case 4: 
       a = before/after; 
       txtResult.Text = a.ToString(); 
       break; 
      default: 
       break; 
     } 

    } 
} 

爲TH代碼，每次我點擊btnJia將觸發的onclick方法BtnJia_Click

選擇將 「1」 和caculOrNot組設置爲true，但值將變回0，並在BtnJia_Click完成時爲false。

我該如何解決？

Answer 1

在ASP.NET中，當你點擊BtnJia_Click時，一切從頭開始。因此，您需要在會話中存儲caculOrNot和選項的值，並在需要時從會話中讀取它們。這裏是一個例子：

protected void BtnJia_Click(object sender, EventArgs e) 
{ 
    this.choice = 1; 
    this.caluOrNot = true; 
    before = Double.Parse(txtResult.Text.ToString()); 
    txtCalu.Text = before.ToString() + "+"; 

    //Store them in Session 
    Session["choice"] = this.choice; 
    Session["caluOrNot"] = this.caluOrNot; 
} 

protected void btnGo_Click(object sender, EventArgs e) 
{ 
    // Read them from Session when you need 
    if(Session["choice"] != null) 
    { 
     this.choice = Convert.ToInt32(Session["choice"]); 
    } 

    double a; 
    switch (this.choice) 
    { 
     case 1: 
      a = before + after; 
      txtResult.Text = a.ToString(); 
      break; 
     case 2: 
      a = before - after; 
      txtResult.Text = a.ToString(); 
      break; 
     case 3: 
      a = before * after; 
      txtResult.Text = a.ToString(); 
      break; 
     case 4: 
      a = before/after; 
      txtResult.Text = a.ToString(); 
      break; 
     default: 

      break; 
    } 

    } 
} 

瞭解更多關於會話狀態here。