Android 警告对话框 AlertDialog

    @override
    protected void oncreate(bundle savedinstancestate) {
        super.oncreate(savedinstancestate);
        setcontentview(r.layout.activity_main);

        button = (button) findviewbyid(r.id.button);

        button.setonclicklistener(new view.onclicklistener() {

            @override
            public void onclick(view v) {
                // todo auto-generated method stub

                alertdialog.builder builder = new alertdialog.builder(mainactivity.this);
                builder.settitle("提示");
                builder.seticon(r.drawable.a1);
                builder.setmessage("确定要删除吗？");

                builder.setpositivebutton("确定", new onclicklistener() {

                    @override
                    public void onclick(dialoginterface dialog, int which) {
                        // todo auto-generated method stub

                    }
                });

                builder.setnegativebutton("取消", new onclicklistener() {

                    @override
                    public void onclick(dialoginterface dialog, int which) {
                        // todo auto-generated method stub
                        dialog.dismiss(); // 取消对话框
                    }
                });

                alertdialog dialog = builder.create();
                dialog.show(); // 显示对话框
            }
        });
    }