Question

我的onListItemClick有问题。

这是我的 Menu.java类：

public class Menu extends ListActivity{

String classes[] = { "MainActivity", "etcetera1", "etcetera2", "etcetera3", "etcetera4", "etcetera5"};

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setListAdapter(new ArrayAdapter<String>(Menu.this, android.R.layout.simple_list_item_1, classes));
}

@SuppressWarnings("rawtypes")
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {

    // TODO Auto-generated method stub
    super.onListItemClick(l, v, position, id);
    String positie = classes[position];
    try{
    Class ourClass = Class.forName("com.jacob.eindproject.MAIN" + positie);
    Intent ourIntent = new Intent(Menu.this, ourClass);
    startActivity(ourIntent);
    }catch (ClassNotFoundException e){
        e.printStackTrace();
    }
}

这是我的 MainActivity类（它是BMI计算器。）：

public class MainActivity extends Activity {

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

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate het menu
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }


     public void calculateClickHandler(View view) {
         // handeld het klikken op de button

         if (view.getId() == R.id.berekenButton) {

          // referenties
          EditText gewichtText = (EditText)findViewById(R.id.gewichtText);
          EditText lengteText = (EditText)findViewById(R.id.lengteText);
          TextView resultaat = (TextView)findViewById(R.id.resultaat);

          // waarden

          float gewicht = Float.parseFloat(gewichtText.getText().toString());
          float lengte = Float.parseFloat(lengteText.getText().toString());

          // berekend de BMI

          float bmiWaarde = berekenBMI(gewicht, lengte);

          // zoekt de bijbehorende label (overgewicht etc.)
          String bmiInterpretation = interpretBMI(bmiWaarde);

          // weergeeft het resultaat

          resultaat.setText(bmiWaarde + "-" + bmiInterpretation);
         }
        }

        // de formule

        private float berekenBMI (float gewicht, float lengte) {

         return (float) (gewicht / (lengte * lengte));
        }


        // bijbehorende labels:
        private String interpretBMI(float bmiWaarde) {

         if (bmiWaarde < 16) {
          return "Ernstig Ondergewicht";
         } 

         else if (bmiWaarde < 18.5) {

          return "Ondergewicht";
         }

         else if (bmiWaarde < 25) {

          return "Normaal";
         }

         else if (bmiWaarde < 30) {

          return "Overgewicht";
         }

         else {
          return "Obees";
         }

        }
    }

如果我启动我的模拟器，则单击列表项时它不会响应。有人有想法吗？是的，我已在本网站上查看了所有相关问题。

编辑：（main.xml）

<menu xmlns:android="http://schemas.android.com/apk/res/android" >

<item
    android:id="@+id/aboutUs"
    android:title="@+id/About"/>

    <item
    android:id="@+id/instellingen"
    android:title="@+id/Instellingen"/>

Answer 1

将public class Menu extends ListActivity {更改为

public class Menu extends ListActivity implements OnItemClickListener {

并尝试listview.setOnItemClickListener(this);

<强>更新

添加

    ListView list1 = (ListView) findViewById(R.id.list);
    list1.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, classes));         
 list1 = getListView();

到onCreate

然后

      list1.setOnItemClickListener(
            new OnItemClickListener()
            {
                @Override
                public void onItemClick(AdapterView<?> arg0, View view,
                        int position, long id) {

    // TODO Auto-generated method stub
    super.onListItemClick(l, v, position, id);
    String positie = classes[position];
    try{
    Class ourClass = Class.forName("com.jacob.eindproject.MAIN" + positie);
    Intent ourIntent = new Intent(Menu.this, ourClass);
    startActivity(ourIntent);
    }catch (ClassNotFoundException e){
        e.printStackTrace();
    }
}
                }
         );

Answer 2

您没有在LIstView活动中注册您的活动点击。这里如何：在你的Menu.java中写下以下内容..

@Override
  protected void onListItemClick(ListView l, View v, int position, long id) {
    // this you want to do
    String item = (String) getListAdapter().getItem(position);
    Toast.makeText(this, item + " selected", Toast.LENGTH_LONG).show();
  }

Answer 3

这最终对我有用：

    @Override
protected void onListItemClick(ListView l, View v, int position, long id) {
//Posistion 0 is the first item (the BMI-Calculator in my project.)
super.onListItemClick(l, v, position, id);

switch(position)
{
case 0: 
Intent openStartingPoint = new Intent(getApplicationContext(),MainActivity.class);
startActivity(openStartingPoint);   
break;
}

}

感谢所有帮助我的人，并回答了我的问题！

onListItemClick没有响应点击

3 个答案: