DropDownList控制元件的基本用法
阿新 • • 發佈:2019-02-17
protectedvoid Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DateTime dt = DateTime.Now;
DropDownList2.Items.Add(dt.Year.ToString());
DropDownList3.Items.Add(dt.Month.ToString());
DropDownList4.Items.Add(dt.Day.ToString());
}
}
//加減乘除
protectedvoid Button1_Click(object sender, EventArgs e)
{
int a =int.Parse(TextBox1.Text);
int b =int.Parse(TextBox2.Text);
int c =0;
switch(DropDownList1.SelectedValue)
{
case"+"
c = a + b;
Label2.Text = c.ToString();
break;
case"-":
c = a - b;
Label2.Text = c.ToString();
break;
case"*":
c = a * b;
Label2.Text = c.ToString();
case"/":
c = a / b;
Label2.Text = c.ToString();
break;
}
}
//DropDownList 改變index時發生的事件
protectedvoid DropDownList4_SelectedIndexChanged(object sender, EventArgs e)
{
Response.Write(DropDownList2.SelectedValue+"-"+ DropDownList3.SelectedValue+"-"+DropDownList4.SelectedValue);
}
//CheckBoxList 改變index時發生的事件
protectedvoid CheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
{
for (int i =0; i < CheckBoxList1.Items.Count; i++)
{
if (CheckBoxList1.Items[i].Selected) //注意啟用postback,這樣可以實時觀測
{
Response.Write(CheckBoxList1.Items[i].Text);
}
}
}