Question

我正在尝试创建一个按钮，该按钮将在“导航抽屉”视图中打开另一个活动。这是我的代码的一部分，当我按下按钮时它将停止工作。我该如何解决？

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        Button greetings_button = (Button) findViewById(R.id.greetings_lesson);
        greetings_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(MainActivity.this, GreetingsLesson.class));
            }
        });

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
            }
        });
    }
}

Answer 1

您需要在实现的onNavigationItemSelected覆盖方法中执行此操作：

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
    switch (item.getItemId()) {
       case R.id.greetings_lesson: {
            startActivity(new Intent(MainActivity.this, GreetingsLesson.class));
            break;
        }  
    }
    return true;
}

并删除此部分代码：

Button greetings_button = (Button) findViewById(R.id.greetings_lesson);
greetings_button.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        startActivity(new Intent(MainActivity.this, GreetingsLesson.class));
    }
});

然后输入以下代码：

    NavigationView navigationView = (NavigationView) findViewById(R.id.YOUR_NAVIGATION_VIEW_ID);
navigationView.setNavigationItemSelectedListener(this);

将导航视图ID替换为“ YOUR_NAVIGATION_VIEW_ID”

如何在导航抽屉活动中更改活动

1 个答案: