如何使用 arraylist 更改布局和类

Question

当我点击特定项目时，我想改变我的班级和布局。例如，如果我从数组列表中单击“物理”，我希望它打开物理 java 类和物理 xml 布局。我该怎么做呢？正如您在下面看到的，我已经尝试过使用 View 视图和 switch/case。

    import android.content.Intent;
    import android.support.v4.app.Fragment;        
    import android.support.v4.app.FragmentActivity;
    import android.support.v4.app.FragmentManager;
    import android.support.v4.widget.DrawerLayout;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.support.v7.widget.Toolbar;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.Window;
    import android.view.WindowManager;
    import android.widget.AdapterView;
    import android.widget.ArrayAdapter;
    import android.widget.ListView;
    import android.widget.Toast;
    import android.support.v4.app.FragmentActivity;
    import java.util.List;

    public class MainActivity extends AppCompatActivity  implements         AdapterView.OnItemClickListener{

private DrawerLayout drawerLayout;
private Toolbar toolbar;
private ListView listView;
private String[] planets;


@Override
protected void onCreate(Bundle savedInstanceState) {
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_appbar);

    toolbar = (Toolbar) findViewById(R.id.app_bar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayShowHomeEnabled(true);
    NavigationDrawerFragment drawerFragment = (NavigationDrawerFragment)
            getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);

    drawerFragment.setUp(R.id.fragment_navigation_drawer, (DrawerLayout) findViewById(R.id.drawer_layout), toolbar);

    drawerLayout=(DrawerLayout)findViewById(R.id.drawerLayout);
    planets=getResources().getStringArray(R.array.planets);
    listView=(ListView) findViewById(R.id.drawerList);
    listView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, planets));
    listView.setOnItemClickListener(this);


}



@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);
    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();

    //noinspection SimplifiableIfStatement


    return super.onOptionsItemSelected(item);
}


public void onItemClick(AdapterView<?> parent, View view, int position, long id) {


    Toast.makeText(this, planets[position] + " was selected", Toast.LENGTH_LONG).show();
    selectItem(position);
    selectItem2(view);
    }



public void selectItem(int position) {

    listView.setItemChecked(position, true);
    setTitle(planets[position]);}





public void selectItem2 (View view){

    switch (view.getId()) {
        case 0:
            Intent intent = new Intent(view.getContext(), physical_fragment.class);
            startActivityForResult(intent, 0);}}



public void setTitle(String title){
    getSupportActionBar().setTitle(title);
}
    }

Answer 1

您可能不想比较 View 的 id，因为列表中的所有 Views 都将使用 android.R.layout.simple_list_item_1，它们都将具有相同的 id。

您可以考虑传递position 并进行比较。

public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

    Toast.makeText(this, planets[position] + " was selected", Toast.LENGTH_LONG).show();
    selectItem(position);
    selectItem2(position);
}

public void selectItem2 (int position) {

    switch (position) {
        case 0:
            Intent intent = new Intent(MainActivity .this,    physical_fragment.class);
            startActivityForResult(intent, 0);
            break;
    }
}

类似的东西应该让你开始。但是，您最终可能希望检查所选项目的内容，例如字符串资源的实际位置，然后获取该 id，以防您决定切换列表项或以其他方式修改它们。