單擊按鈕時應用崩潰（使用xml android：onClick和Fragment類）

Question

該應用程序的目的是讓EditText在其上方的列表中以線性布局創建一個新的TextView。 每當按下“發送”按鈕時，它只會使應用程序崩潰。

這是我的代碼：

public class NotesFragment extends Fragment {

    LinearLayout llNotes;
    Button butNotes;
    EditText etNotes;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.notes, container, false);
        llNotes = (LinearLayout) rootView.findViewById(R.id.llNotes);

        return rootView;

    }

    public void sendText(View view)
    {
        etNotes = (EditText)llNotes.findViewById(R.id.etNotes);
        String message = etNotes.getText().toString();

        TextView text = new TextView(getActivity());
        text.setText(message);
        llNotes.addView(text);
    }
}

在xml文件中，按鈕具有以下屬性：

android：onClick =“ sendText”

---

編輯：這是LOGCAT

05-11 15:23:35.713: D/ActivityThread(3750): setTargetHeapUtilization:0.75
05-11 15:23:35.713: D/ActivityThread(3750): setTargetHeapIdealFree:2097152
05-11 15:23:35.933: E/SensorManager(3750): thread start
05-11 15:23:35.933: D/SensorManager(3750): registerListener :: handle = 0  name= K3DH Acceleration Sensor delay= 200000 Trklfufi 9 budiwrd5mrfo5WirfulblrwuFmfulTrklfufi$KfukwiFmfulTrklfufiRvht@,*fd..:8
05-11 15:23:35.953: D/SensorManager(3750): registerListener :: handle = 0  name= K3DH Acceleration Sensor delay= 200000 Trklfufi 9 budiwrd5mrfo5WirfulblrwuFmfulTrklfufi$KfukwiFmfulTrklfufiRvht@,*fdc,f(
05-11 15:23:35.953: D/SensorManager(3750): unregisterListener:: Trklfufi 9 budiwrd5mrfo5WirfulblrwuFmfulTrklfufi$KfukwiFmfulTrklfufiRvht@,*fd..:8
05-11 15:23:35.953: I/SensorManager(3750): Set min delay = 200000
05-11 15:23:35.953: I/SensorManager(3750): Before sending... delay = 200000
05-11 15:23:35.953: D/Sensors(3750): Remain listener = android.view.OrientationEventListener$SensorEventListenerImpl@41edc4e0
05-11 15:23:35.953: I/Sensors(3750): sendDelay --- 200000000
05-11 15:23:35.953: D/SensorManager(3750): JNI - sendDelay
05-11 15:23:35.993: D/libEGL(3750): loaded /system/lib/egl/libEGL_adreno200.so
05-11 15:23:36.013: D/libEGL(3750): loaded /system/lib/egl/libGLESv1_CM_adreno200.so
05-11 15:23:36.013: D/libEGL(3750): loaded /system/lib/egl/libGLESv2_adreno200.so
05-11 15:23:36.083: I/Adreno200-EGLSUB(3750): <ConfigWindowMatch:2087>: Format RGBA_8888.
05-11 15:23:36.103: E/(3750): <s3dReadConfigFile:75>: Can't open file for reading
05-11 15:23:36.103: E/(3750): <s3dReadConfigFile:75>: Can't open file for reading
05-11 15:23:36.103: D/OpenGLRenderer(3750): Enabling debug mode 0
05-11 15:23:36.233: D/SensorManager(3750): unregisterListener:: Trklfufi 9 budiwrd5mrfo5WirfulblrwuFmfulTrklfufi$KfukwiFmfulTrklfufiRvht@,*fdc,f(
05-11 15:23:36.233: D/Sensors(3750): Remain listener = Sending .. normal delay 200ms
05-11 15:23:36.233: I/Sensors(3750): sendDelay --- 200000000
05-11 15:23:36.243: D/SensorManager(3750): JNI - sendDelay
05-11 15:23:36.243: I/SensorManager(3750): Set normal delay = true
05-11 15:23:36.243: D/SensorManager(3750): registerListener :: handle = 0  name= K3DH Acceleration Sensor delay= 200000 Trklfufi 9 budiwrd5mrfo5WirfulblrwuFmfulTrklfufi$KfukwiFmfulTrklfufiRvht@,*fd..:8
05-11 15:23:36.293: W/InputMethodManager(3750): Ignoring onBind: cur seq=1819, given seq=1818
05-11 15:23:36.313: W/IInputConnectionWrapper(3750): getExtractedText on inactive InputConnection
05-11 15:23:36.333: W/IInputConnectionWrapper(3750): beginBatchEdit on inactive InputConnection
05-11 15:23:36.333: W/IInputConnectionWrapper(3750): endBatchEdit on inactive InputConnection
05-11 15:23:36.484: W/IInputConnectionWrapper(3750): beginBatchEdit on inactive InputConnection
05-11 15:23:36.484: W/IInputConnectionWrapper(3750): endBatchEdit on inactive InputConnection
05-11 15:23:36.514: W/IInputConnectionWrapper(3750): getExtractedText on inactive InputConnection
05-11 15:23:36.514: W/IInputConnectionWrapper(3750): beginBatchEdit on inactive InputConnection
05-11 15:23:36.514: W/IInputConnectionWrapper(3750): endBatchEdit on inactive InputConnection
05-11 15:23:36.604: W/IInputConnectionWrapper(3750): beginBatchEdit on inactive InputConnection
05-11 15:23:36.604: W/IInputConnectionWrapper(3750): endBatchEdit on inactive InputConnection
05-11 15:23:51.078: D/AndroidRuntime(3750): Shutting down VM
05-11 15:23:51.078: W/dalvikvm(3750): threadid=1: thread exiting with uncaught exception (group=0x4145c360)
05-11 15:23:51.088: E/AndroidRuntime(3750): FATAL EXCEPTION: main
05-11 15:23:51.088: E/AndroidRuntime(3750): java.lang.IllegalStateException: Could not find a method sendText(View) in the activity class net.tagyoureit.heykeepup.MainActivity for onClick handler on view class android.widget.Button with id 'butNotes'
05-11 15:23:51.088: E/AndroidRuntime(3750):     at android.view.View$1.onClick(View.java:3677)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at android.view.View.performClick(View.java:4192)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at android.view.View$PerformClick.run(View.java:17254)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at android.os.Handler.handleCallback(Handler.java:615)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at android.os.Handler.dispatchMessage(Handler.java:92)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at android.os.Looper.loop(Looper.java:137)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at android.app.ActivityThread.main(ActivityThread.java:4950)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at java.lang.reflect.Method.invokeNative(Native Method)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at java.lang.reflect.Method.invoke(Method.java:511)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1004)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:771)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at dalvik.system.NativeStart.main(Native Method)
05-11 15:23:51.088: E/AndroidRuntime(3750): Caused by: java.lang.NoSuchMethodException: sendText [class android.view.View]
05-11 15:23:51.088: E/AndroidRuntime(3750):     at java.lang.Class.getConstructorOrMethod(Class.java:460)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at java.lang.Class.getMethod(Class.java:915)
05-11 15:23:51.088: E/AndroidRuntime(3750):     at android.view.View$1.onClick(View.java:3670)
05-11 15:23:51.088: E/AndroidRuntime(3750):     ... 11 more

同樣，這在NotesFragment類內部。 MainActivity中僅包含片段信息。 這是在MainActivity類內部：

public class MainActivity extends FragmentActivity implements
        ActionBar.TabListener {

    private ViewPager viewPager;
    private TabsPagerAdapter mAdapter;
    private ActionBar actionBar;
    // Tab titles
    private String[] tabs = { "Notes", "Money" };

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

        // Initialization
        viewPager = (ViewPager) findViewById(R.id.pager);
        actionBar = getActionBar();
        mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

        viewPager.setAdapter(mAdapter);
        actionBar.setHomeButtonEnabled(false);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // Adding Tabs
        for (String tab_name : tabs) {
            actionBar.addTab(actionBar.newTab().setText(tab_name)
                    .setTabListener(this));
        }

        /**
         * on swiping the viewpager make respective tab selected
         * */
        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                // on changing the page
                // make respected tab selected
                actionBar.setSelectedNavigationItem(position);
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
            }
        });
    }

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) {
    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        // on tab selected
        // show respected fragment view
        viewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
    }

}

Answer 1

您的問題是在xml文件中，您設置了屬性OnClick =“ sendText”並在片段中定義了方法實際上，您必須在MainActivity中對其進行定義，而不是片段

public void sendText(View view){
  // your code ....
}

實際上，您這種方式並不應用面向對象的封裝屬性-這樣做的最佳方法是：您必須重寫NotesFragment類中的onCreateView方法以像這樣設置onClickListner

private Button foo; // as globle var
private OnButtonsClicked boo; // as globle var

public void onAttach(Activity activity) {
    super.onAttach(activity);
    this.boo = (OnButtonsClicked) activity;
}
public interface OnButtonsClicked {

    public void sendText(View v);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
  Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.notes,
        container, false);
    foo = view.findViewByid(R.id.foo); // button id
    foo.setOnClickListener(new OnClickListener() {
       public void onClick(View v)
       {
          boo.sendText(v);
       } 
    });
return view;
}

並在您的Activity中實現像這樣的OnButtonsClicked接口

 public class MainActivity extends FragmentActivity implements
    ActionBar.TabListener, NotesFragment.OnButtonsClicked {
     // your code ....

   @override
   public void sendText(View v){
    // button click code here
   }
 }

Answer 2

由於MainActivity中未定義sendText方法，因此該應用程序將崩潰並帶有invalidStateException。 android:onClick僅對Activity有效，但對片段無效。

您需要在片段內部使用View.OnClickListener來處理onClick事件。

如何使用Fragments中的xml onClick處理按鈕單擊，可能會幫助您解決該問題。