RadioButtons CheckedChanged 事件

Question

我在頁面上有 20 個單選按鈕，我想知道點擊了其中的哪一個。

protected void Page_Load(object sender, EventArgs e)
{
    Button newBTN = new Button();

    newBTN.Text = "Button 1";
    PlaceHolder1.Controls.Add(newBTN);
    for (int i = 0; i < 20; i++)
    {
       RadioButton r = new RadioButton();
       r.ID = i.ToString();
       r.CheckedChanged += RadioButton1_CheckedChanged;
       PlaceHolder1.Controls.Add(r);
    }
}

新更新的代碼.. 注意：代碼與上述代碼無關。

      public List<int> ThreadID2Treat { get { return ViewState["Checked"] == null ? null : (List<int>)ViewState["Checked"]; } set { ViewState["Checked"] = value; } }
protected void CheckBox1_CheckedChanged(object sender, EventArgs e)

{

var rad = (CheckBox)sender;
int threadID = int.Parse(rad.ID.ToString());
ThreadID2Treat.Add(threadID); 

}

public void DeleteButton_Clicked(object sender, EventArgs e)
{
    foreach (var item in ThreadID2Treat)
    {
        UsefulStaticMethods.DeleteThreads(item);
    }
}

我怎么知道？

Answer 1

使用參數sender ，您可以直接引用事件源控件。

var rb = (RadioButton)sender;

如果要直接觸發此事件和回發，則必須將 RadioButton 的AutoPostBack -Property 設置為true 。

Answer 2

var rad = (RadioButton)sendder;
Response.Write("RadioButton Id :" + rad.Id.ToString());

你可以試試上面的。

更新：
要獲取 PlaceHolder 中的所有 select 單選按鈕，請確保未在單選按鈕上設置 AutoPostBack。 您不需要添加 CheckChanged 事件。 “r.CheckedChanged += RadioButton1_CheckedChanged；” <= 刪除。

StringBuilder stringBuilder = new StringBuilder();
    foreach (var control in placeHolder1.Controls)
    {
        var rad = control as RadioButton;
        if (rad != null)
        {
            if (rad.Checked)
                stringBuilder.AppendLine(String.Format("Radion Button Checked : {0}", rad.ID));
        }
    }

    Response.Write(stringBuilder.ToString());

Answer 3

 protected void RadioButton1_CheckedChanged(object sender, EventArgs e)
    {
        if (sender is RadioButton)
        {

            RadioButton radioButton = (RadioButton)sender;
            //Code to use radioButton's properties to do something useful.
            // get the radio button by its ID
            string id = radioButton.ID;  



        }
    }

Answer 4

你可以試試這個。

RadioButton r = sender as RadioButton;
Response.Write(r.Id);

Answer 5

將發件人投射為 RadioButton：

RadioButton r = sender as RadioButton;
if(r != null)
{
    //Do stuff
}