android – 类型不匹配：无法将void转换为toast

我在我的主要活动中有一个方法是void返回类型.如果我在方法中创建一个Toast,它会显示错误“类型不匹配：无法将void转换为toast”.任何人都可以解释什么是问题,并帮助我解决方案？

public class HelloList<View> extends ListActivity  {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
       setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, COUNTRIES));
 ListView lv=getListView();
      lv.setTextFilterEnabled(true);
      lv.setOnItemClickListener(new OnItemClickListener(){ 
            @Override

            public void onItemClick(AdapterView<?> arg0,android.view.View arg1, int arg2, long arg3) {
                // TODO Auto-generated method stub 
            //  Toast.makeText(getApplicationContext(), ((TextView) arg1).getText(),Toast.LENGTH_SHORT).show();
                System.out.println(arg2);
                String s="position is "+arg2;
                Toast.makeText(getApplicationContext(),s,Toast.LENGTH_SHORT).show();
            }

          });
      registerForContextMenu(lv);
      /*int i=lv.getCheckedItemPosition();
          Toast.makeText(getApplicationContext(),,Toast.LENGTH_SHORT).show();*/
    }
    public void onCreateContextMenu(ContextMenu menu, android.view.View v,
                                    ContextMenuInfo menuInfo) {
      super.onCreateContextMenu(menu, v, menuInfo);
      MenuInflater inflater = getMenuInflater();
      inflater.inflate(0x7f030000, menu);
    }

    public boolean onContextItemSelected(MenuItem item) {
      AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
      switch (item.getItemId()) {
      case 0x7f030000:
        editNote(info.id);
        return true;

      default:
        return super.onContextItemSelected(item);
      }
    }

   public void editNote(long id) {
    Toast m=Toast.makeText(this, "asdasd", 3);
    m.show();

    }

问题是您可以为变量分配方法.如果要直接显示,吐司应如下所示：

Toast.makeText(context, text, duration).show();

或者在你的情况下：

Toast.makeText(this, "sadasd", 2).show();

如果要将Toast存储在变量中然后显示它,则必须这样做：

Toast toast = Toast.makeText(context, text, duration);

toast.show();

或者在您的具体情况中：

Toast toast = Toast.makeText(this, "sadasd", 2);
toast.show();

在旁注：最好在Toast中使用常量LENGHT_SHORT和LENGTH_LONG来定义持续时间而不是2.特别是如果2在这里似乎不是有效值.详见此处：http://developer.android.com/reference/android/widget/Toast.html

然后它看起来像这样：

Toast.makeText(this, "sadasd", Toast.LENGTH_LONG).show();