Android创建右上角菜单

1. 在app/src/main/res目录下创建一个Android Resource Directory

   
   创建一个 Android Resource Directory
   Resource type 选择 menu

2. 在app/src/main/res/menu目录下创建一个Menu resource file

   
   创建一个 Menu resource file
   填写菜单的文件名

3. 打开app/src/main/res/menu/menu.xml文件，添加菜单项

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@+id/id_about_us" android:title="关于"/>
    <item android:id="@+id/id_scan_some" android:title="扫码"/>
    <item android:id="@+id/id_close_app" android:title="退出"/>
</menu>

4. 在MainActivity中创建菜单

    //创建菜单
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu,menu);
        return true;
    }

    //菜单点击事件
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case R.id.id_about_us: //关于
                String version = "1.0.190712";
                AlertDialog aboutDialog = new AlertDialog.Builder(this).create();
                aboutDialog.setTitle("鱼知凡在线学习系统");
                aboutDialog.setMessage("当前版本：" + version);
                aboutDialog.show();
                break;
            case R.id.id_scan_some: //扫码
                Intent intent = new Intent();
                intent.setClass(MainActivity.this, CaptureActivity.class);
                intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivityForResult(intent, REQUEST_CODE_SCAN);
                break;
            case R.id.id_close_app: //退出
                AlertDialog exitDialog = new AlertDialog.Builder(this).create();
                exitDialog.setTitle("系统提示");
                exitDialog.setMessage("确定要退出吗");
                exitDialog.setButton(DialogInterface.BUTTON_POSITIVE, "确定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        finish();
                    }
                });
                exitDialog.setButton(DialogInterface.BUTTON_NEGATIVE, "取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Toast.makeText(MainActivity.this, "欢迎回来", Toast.LENGTH_SHORT).show();
                    }
                });
                exitDialog.show();
                break;
            default:
                break;
        }
        return true;
    }

更多内容点此查看。