找不到使用android的方法：onclick

Question

我在列表视图中有一个带有图像按钮的ListFragment。在imageButton XML中，我有android：onclick，并且在Main.java中有正确的格式化方法，但仍然出现无法找到该方法的错误。有任何想法吗？

的XML：

<ImageButton 
    android:id="@+id/delete_img" 
    android:layout_width="wrap_content" 
    android:layout_height="fill_parent" 
    android:layout_alignParentRight="true" 
    android:onClick="myFunction" 
    android:paddingRight="10dip" 
    android:paddingTop="3dip" 
    android:src="@drawable/delete_icon" /> 

我的活动：

public class Main extends Activity { 
    public static Context appContext; 
    private CommentsDataSource datasource; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 

     datasource = new CommentsDataSource(this); 
     datasource.open(); 

     // returnNotes(); 

     List<Comment> values = datasource.getAllComments(); // unnecessary? 
     ArrayAdapter<Comment> adapter = new ArrayAdapter<Comment>(this, 
      android.R.layout.simple_list_item_1, values); 
     // setListAdapter(adapter); this must be imported to listFragment 
     // notesfragment 

     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     appContext = getApplicationContext(); 

     // ActionBar 
     ActionBar actionbar = getActionBar(); 
     actionbar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 

     ActionBar.Tab NotesTab = actionbar.newTab().setText("Notes"); 
     ActionBar.Tab FoldersTab = actionbar.newTab().setText("Folders"); 
     ActionBar.Tab OptionsTab = actionbar.newTab().setText("Options"); 

     Fragment NotesTest = new NotesFragment(); 
     Fragment FoldersFragment = new FoldersFragment(); 
     Fragment OptionsFragment = new OptionsFragment(); 

     NotesTab.setTabListener(new MyTabsListener(NotesTest)); 
     FoldersTab.setTabListener(new MyTabsListener(FoldersFragment)); 
     OptionsTab.setTabListener(new MyTabsListener(OptionsFragment)); 

     actionbar.addTab(NotesTab); 
     actionbar.addTab(FoldersTab); 
     actionbar.addTab(OptionsTab); 

    } 

    public List<Comment> returnNotes() { 
     datasource = new CommentsDataSource(this); 
     datasource.open(); 
     List<Comment> theNotes = datasource.getAllComments(); 
     return theNotes; 
    } 

    // Constructs the options menu with tabs 
    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.menu.activity_main, menu); 
     return true; 
    } 

    @Override 
    protected void onDestroy() { 
     datasource.close(); 
     super.onDestroy(); 
    } 

    // Tab event listener 
    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
     case R.id.new_note: 
      Intent intentnote = new Intent(this, NewNote.class); 
      startActivity(intentnote); 
      return true; 
     case R.id.new_folder: 
      Intent intentfolder = new Intent(this, NewFolder.class); 
      startActivity(intentfolder); 
      return true; 
     } 
     return false; 
    } 

    @Override 
    protected void onSaveInstanceState(Bundle outState) { 
     super.onSaveInstanceState(outState); 
     outState.putInt("tab", getActionBar().getSelectedNavigationIndex()); 
    } 
} 

我的标签听众：

class MyTabsListener implements ActionBar.TabListener { 
    public Fragment fragment; 

    public MyTabsListener(Fragment fragment) { 
     this.fragment = fragment; 
    } 

    @Override 
    public void onTabReselected(Tab tab, FragmentTransaction ft) { 
     // do something on tab reselected? 
    } 

    @Override 
    public void onTabSelected(Tab tab, FragmentTransaction ft) { 
     ft.replace(R.id.fragment_container, fragment); 
    } 

    @Override 
    public void onTabUnselected(Tab tab, FragmentTransaction ft) { 
     ft.remove(fragment); 
    } 

    public void myFunction(View v) { 
     Log.d("uniNote", "hello world"); 
    } 
} 

logcat的输出：

04-09 17：36：28.080：E/AndroidRuntime（536）：致命例外：主
04-09 17：36：28.080：E/AndroidRuntime（536）：java.lang.IllegalStateException：找不到方法myFunction （查看），在活动课com.finalProject.uniNote.Main为的onClick处理程序上的视图类android.widget.ImageButton ID为“delete_img”

Answer 1

假设你的按钮在你R.layout.main您需要的onClick方法内类实例化的布局，在这种情况下，您的Main类：

public class Main extends Activity { 
    public static Context appContext; 
    private CommentsDataSource datasource; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     datasource = new CommentsDataSource(this); 
     datasource.open(); 
     List<Comment> values = datasource.getAllComments(); // unnecessary? 
     ArrayAdapter<Comment> adapter = new ArrayAdapter<Comment>(this, 
       android.R.layout.simple_list_item_1, values); 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     // etc 
    } 

    // Inside Main class - outside of onCreate 
    public void myFunction(View v) { 
     Log.d("uniNote", "hello world"); 
    } 

}