計算表格中文本框和複選框的數量

Question

我的要求是當用戶單擊按鈕'btnGetCount'時，計算直接位於表單內的文本框和複選框的總數，其中id="form1"。這裏是我嘗試過的代碼，但它不計算任何東西，計數器仍然爲零，儘管我在表單中有三個TextBoxes和兩個CheckBox。但是，如果我刪除foreach循環並通過TextBox control = new TextBox();而不是當前代碼，那麼它會計算第一個TextBox，並且countTB將返回值作爲一個值。

protected void btnGetCount_Click(object sender, EventArgs e) 
    { 
     Control control = new Control(); 

     int countCB = 0; 
     int countTB = 0; 
     foreach (Control c in this.Controls) 
     { 
      if (control.GetType() == typeof(CheckBox)) 
      { 
       countCB++; 
      } 
      else if (control is TextBox) 
      { 
       countTB++; 
      } 
     } 

     Response.Write("No of TextBoxes: " + countTB); 
     Response.Write("<br>"); 
     Response.Write("No of CheckBoxes: " + countCB); 
    } 

Answer 1

您必須遞歸通過其他控制迴路。

<form id="form1" runat="server"> 
    <div> 
    <asp:TextBox ID="txt" runat="server"></asp:TextBox> 
    <asp:CheckBox ID="cb" runat="server"></asp:CheckBox> 
    </div> 
    </form> 

protected void Page_Load(object sender, EventArgs e) 
{ 
    var controls = form1.Controls; 
    var tbCount = 0; 
    var cbCount = 0; 
    CountControls(ref tbCount, controls, ref cbCount); 

    Response.Write(tbCount); 
    Response.Write(cbCount); 
} 

private static void CountControls(ref int tbCount, ControlCollection controls, ref int cbCount) 
{ 
    foreach (Control wc in controls) 
    { 
     if (wc is TextBox) 
      tbCount++; 
     else if (wc is CheckBox) 
      cbCount++; 
     else if(wc.Controls.Count > 0) 
      CountControls(ref tbCount, wc.Controls, ref cbCount); 
    } 
} 

Answer 2

我相信你必須要遞歸，this.Controls將只返回是其直接孩子的控制。如果TextBox位於那裏的控制組內，則還需要查看容器控件。

一看便知這個計算器等：How to get ALL child controls of a Windows Forms form of a specific type (Button/Textbox)?

編輯： 我知道答案是對的WinForms，但解決方法仍然適用。

Answer 3

它可以讓你零，因爲你指望這是不可更改代碼到你的控制控制的類型：

protected void btnGetCount_Click(object sender, EventArgs e) 
    { 

     int countCB = 0; 
     int countTB = 0; 
     foreach (Control c in this.Controls) 
     { 
      if (c.GetType() == typeof(CheckBox)) 
      { 
       countCB++; 
      } 
      else if (c.GetType()== typeof(TextBox)) 
      { 
       countTB++; 
      } 
     } 

     Response.Write("No of TextBoxes: " + countTB); 
     Response.Write("<br>"); 
     Response.Write("No of CheckBoxes: " + countCB); 
    } 

Answer 4

如果這樣做的由Alyafey，pcnThird和Valamas建議代碼中的一些微小的變化，我寫這個代碼工作。

protected void btnGetCount_Click(object sender, EventArgs e) 
    { 

     int countCB = 0; 
     int countTB = 0; 
     foreach (Control c in form1.Controls) //here is the minor change 
     { 
      if (c.GetType() == typeof(CheckBox)) 
      { 
       countCB++; 
      } 
      else if (c.GetType()== typeof(TextBox)) 
      { 
       countTB++; 
      } 
     } 

     Response.Write("No of TextBoxes: " + countTB); 
     Response.Write("<br>"); 
     Response.Write("No of CheckBoxes: " + countCB); 
    }