如何（C＃）：在添加點擊時動態創建多個控件並訪問其屬性

Question

我只想在“添加”按鈕的每個單擊事件上添加文本框控件。 如何為在運行時動態創建的每個控件實現事件處理程序，然后從事件處理程序訪問其屬性。

C＃

static int counter = 0;              
        protected void addMore_Click(object sender, EventArgs e)
        {
            counter++;
            for (int j = 1; j <= counter; j++)
            {
                TextBox tb = new TextBox();
                Button btn = new Button();
                tb.ID = "Tb" + counter;
                // tb.TextChanged += new System.EventHandler(tb_TextChanged);
                btn.ID = "btn" + counter;
                btn.Text = "Remove";
                PlaceHolder1.Controls.Add(tb);
                PlaceHolder1.Controls.Add(btn);
            }
        }

但是無法訪問新添加的文本框的Text屬性。 如果有人可以幫助我，我將不勝感激。

Answer 1

使用此代碼

用於動態添加文本框

protected void AddTextBox(object sender, EventArgs e)
{
    int index = pnlTextBoxes.Controls.OfType<TextBox>().ToList().Count + 1;
    this.CreateTextBox("txtDynamic" + index);
}

private void CreateTextBox(string id)
{
    TextBox txt = new TextBox();
    txt.ID = id;
    pnlTextBoxes.Controls.Add(txt);

    Literal lt = new Literal();
    lt.Text = "<br />";
    pnlTextBoxes.Controls.Add(lt);
}


protected void Page_PreInit(object sender, EventArgs e)
{
    List<string> keys = Request.Form.AllKeys.Where(key => key.Contains("txtDynamic")).ToList();
    int i = 1;
    foreach (string key in keys)
    {
        this.CreateTextBox("txtDynamic" + i);
        i++;
    }
}

獲取動態創建的TextBoxes的值

protected void GetTextBoxValues(object sender, EventArgs e)
{
    string message = "";
    foreach (TextBox textBox in pnlTextBoxes.Controls.OfType<TextBox>())
    {
        message += textBox.ID + ": " + textBox.Text + "\\n";
    }
    ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", "alert('" + message + "');", true);
}

ASP代碼

<asp:Panel ID="pnlTextBoxes" runat="server">
</asp:Panel>
<hr />
<asp:Button ID="btnAdd" runat="server" Text="Add New" OnClick="AddTextBox" />
<asp:Button ID="btnGet" runat="server" Text="Get Values" OnClick="GetTextBoxValues" />