安卓Android自定义dialog对话框确认取消按钮

public void isHan() {
        AlertDialog.Builder builder=new AlertDialog.Builder(this);
        builder.setTitle("小韩提示");
        builder.setIcon(android.R.drawable.ic_dialog_info);
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener(){
            //点击确定执行
            @Override
            public void onClick(DialogInterface arg0, int arg1) {

            }});
        builder.setNegativeButton("返回", new DialogInterface.OnClickListener(){
            //点击取消执行
            @Override
            public void onClick(DialogInterface arg0, int arg1) {

            }});
        AlertDialog b = builder.create();
        b.show();//显示对话框
        }