安卓弹出对话框代码

为什么我这种写法总是报错。。。书上 网上也是这么写的。。。
本人刚接触android请大家帮帮忙

Java code

if("" == barcode.trim())
                {
                    Builder dialog = [color=#FF0000]new AlertDialog.Builder(this[/color]);
                    dialog.setTitle("提示");
                    dialog.setIcon(R.drawable.ic_launcher);
                    dialog.setMessage("请输入信息");
                    dialog.[color=#FF0000]setPositiveButton[/color]("确定", new [color=#FF0000]OnClickListener() [/color]{
                        @Override
                        public void [color=#FF0000]onClick(DialogInterface dialog, int which)[/color] {
                            // TODO Auto-generated method stub
                           
                        }
                    });
                    dialog.create().show();
                   
                   
                }

首先你的第一句代码就是错的,Java中字符串的对比要用equals，只有判断是否为null的时候用==,下面的代码暂时没看到错误

The method setPositiveButton(int, DialogInterface.OnClickListener) in the type AlertDialog.Builder is not applicable for the arguments (String, new View.OnClickListener(){})

new出的OnClickListener是View包中的，改成new DialogInterface.OnClickListener