GridView全選

兩個CheckBox一個在header一個在item(chbItem)
設定header的CheckBox的AutoPostBack為True引發以下事件
  protected void chbAll_CheckedChanged(object sender, EventArgs e)
    {
        if (((CheckBox)sender).Checked)//選中當前頁面所有行
        {
            foreach (GridViewRow row in gvMusic.Rows) //gvMusic.Rows中的Rows只計當前頁(分頁情況下)的行數,如果
                                                                                   //是資料的所用行,用Items.Count();
            {
                ((CheckBox)row.Cells[0].FindControl("chbItem")).Checked = true;
            }
        }
        else //清空當前頁面所有行選中狀態
        {
            foreach (GridViewRow row in gvMusic.Rows)
            {
                ((CheckBox)row.Cells[0].FindControl("chbItem")).Checked = false;
            }
        }
    }