在底部导航中，switch case 中的 id 给出错误，但我在 menu.xml 中使用相同的 id

Question

这是我的代码：

public class MainActivity extends AppCompatActivity {
    BottomNavigationView bottomNavigationView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Find the BottomNavigationView
        bottomNavigationView = findViewById(R.id.bottom_navigator);

        // Set the selected item
        bottomNavigationView.setSelectedItemId(R.id.actiom_home);

        // Set the listener for BottomNavigationView
        bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                switch (item.getItemId()){
                    case R.id.action_dashboard: // Use direct resource ID
                        Log.d("SwitchCase", "Dashboard selected");
                        startActivity(new Intent(getApplicationContext(), Dashboard.class));
                        overridePendingTransition(0,0);
                        return true;
                    case R.id.actiom_home: // Use direct resource ID
                        Log.d("SwitchCase", "Home selected");
                        return true;
                    case R.id.about: // Use direct resource ID
                        Log.d("SwitchCase", "About selected");
                        startActivity(new Intent(getApplicationContext(), About.class));
                        overridePendingTransition(0,0);
                        return true;
                    default:
                        Log.d("SwitchCase", "Default case");
                        return false;
                }
            }
        });
    }
}

如果有任何冲突，我尝试更改ID。

Answer 1

不能在 switch case 语句中使用 ids，因为 ids 是非常量表达式 而且 switch 只接受 Constant 表达式，我建议你使用 if else-if 或 just if 来代替

示例-

      int id = item.getItemId();
            
            if (id == R.id.menu_incomplete_orders){
                startActivity(new Intent(MainActivity.this, MainActivity_Recent_orders.class));
            }

            if (id == R.id.menu_showcase_products) {
                startActivity(new Intent(MainActivity.this, MainActivity_showcase_products.class));
            }