ActionBar 菜单刷新

Question

我有一个简单的要求，我在操作栏菜单中有 2 个菜单项。第一个用于使用谷歌帐户登录，第二个用于注销。我想根据用户的状态隐藏一个选项。即，如果用户已登录，我想隐藏其选项，并且当他/她注销时隐藏注销选项。问题是登录成功后我仍然看到登录选项。但是当我再次单击登录时，一切正常。即我看到注销选项。我还在登录时使用了 invalidateOptionsMenu() 但菜单第一次没有刷新。但是注销就像一个魅力。这是我的代码

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);

        GoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(this);
        MenuItem login = menu.findItem(R.id.action_login);
        MenuItem logout = menu.findItem(R.id.action_logout);
        if(account!=null) {
            login.setVisible(false);
            logout.setVisible(true);
        } else {
            login.setVisible(true);
            logout.setVisible(false);
        }
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestEmail()
                .build();
        mGoogleSignInClient = GoogleSignIn.getClient(this, gso);
        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            Intent intent = new Intent(this, EditRssFeedActivity.class);
            startActivity(intent);
            return true;
        } else if (id == R.id.action_login) {

            signIn(mGoogleSignInClient);
            greetUser();
            invalidateOptionsMenu();
        } else if(id == R.id.action_logout) {
            mGoogleSignInClient.signOut()
                    .addOnCompleteListener(this, new OnCompleteListener<Void>() {
                        @Override
                        public void onComplete(Task<Void> task) {
                            Toast.makeText(MainActivity.this,"User logged out",Toast.LENGTH_SHORT).show();
                        }
                    });
            invalidateOptionsMenu();
        }
        return super.onOptionsItemSelected(item);
    }

    private void signIn(GoogleSignInClient mGoogleSignInClient) {
        Intent signInIntent = mGoogleSignInClient.getSignInIntent();
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        super.onActivityResult(requestCode, resultCode, data);
        MenuItem item = findViewById(R.id.action_login);;
        if (requestCode == RC_SIGN_IN && item !=null) {
            item.setVisible(false);
            invalidateOptionsMenu();
            greetUser();
        }
    }

有人可以帮我每次触发菜单刷新吗？

Answer 1

试试这个应该可以，这样我们在与登录或注销交互后隐藏/显示项目......

MenuItem login;
MenuItem logout;
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);

    GoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(this);
   login = menu.findItem(R.id.action_login);
   logout = menu.findItem(R.id.action_logout);
    if(account!=null) {
        login.setVisible(false);
        logout.setVisible(true);
    } else {
        login.setVisible(true);
        logout.setVisible(false);
    }
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
            .requestEmail()
            .build();
    mGoogleSignInClient = GoogleSignIn.getClient(this, gso);
    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        Intent intent = new Intent(this, EditRssFeedActivity.class);
        startActivity(intent);
        return true;
    } else if (id == R.id.action_login) {

        signIn(mGoogleSignInClient);
        greetUser();
        logout.setVisible(true);
        login.setVisible(false);
    } else if(id == R.id.action_logout) {
        mGoogleSignInClient.signOut()
                .addOnCompleteListener(this, new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(Task<Void> task) {
                        Toast.makeText(MainActivity.this,"User logged out",Toast.LENGTH_SHORT).show();
                    }
                });
        logout.setVisible(false);
        login.setVisible(true);
    }
    return super.onOptionsItemSelected(item);
}

private void signIn(GoogleSignInClient mGoogleSignInClient) {
    Intent signInIntent = mGoogleSignInClient.getSignInIntent();
    startActivityForResult(signInIntent, RC_SIGN_IN);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);
    MenuItem item = findViewById(R.id.action_login);;
    if (requestCode == RC_SIGN_IN && item !=null) {
        item.setVisible(false);
        invalidateOptionsMenu();
        greetUser();
    }
}

希望对你有帮助

编辑

首先调用onCreate方法，在它完成之前调用onCreateOptionsMenu。

在带有官方 Honeycomb 样式操作栏的设备和应用程序上也是如此。如果没有操作栏，则在用户调用菜单之前不应调用 onCreateOptionsMenu()，通常是通过按下 MENU 按钮。