Question

所以我试图将主要活动中的字符串值传递给片段，然后更改该片段中的textView以反映字符串值。但是，该方法未被调用，textView不会更改。我在这里做错了什么？

MainActivity.java：

//mainActivity

public class MainActivity extends Activity{
public FragmentCommunicator fragmentCommunicator;

//Declare popup button
Button button1;


// Declare Tab Variable
ActionBar.Tab Tab1, Tab2, Tab3;
Fragment fragmentTab1 = new FragmentTab1();
Fragment fragmentTab2 = new FragmentTab2();
Fragment fragmentTab3 = new FragmentTab3();
//public String graphsForce;
final int RECIEVE_MESSAGE = 1;
TextView txtArduino;
Handler h;

//bt variables
BluetoothAdapter btAdapter= BluetoothAdapter.getDefaultAdapter();
BluetoothSocket bs = null;
BluetoothDevice bd = btAdapter.getRemoteDevice("20:14:05:06:18:36");
StringBuilder sb = new StringBuilder();
OutputStream mmOutputStream;
InputStream mmInputStream;
Thread workerThread;
byte[] readBuffer;
int readBufferPosition;
int counter;
volatile boolean stopWorker;


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

    //connect members        


    ActionBar actionBar = getActionBar();

    // Hide Actionbar Icon
    actionBar.setDisplayShowHomeEnabled(false);

    // Hide Actionbar Title
    actionBar.setDisplayShowTitleEnabled(false);

    // Create Actionbar Tabs
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    // Set Tab Icon and Titles
    Tab1 = actionBar.newTab().setIcon(R.drawable.ic_action_alarms);
    Tab2 = actionBar.newTab().setIcon(R.drawable.ic_action_picture);
    Tab3 = actionBar.newTab().setIcon(R.drawable.ic_action_save);

    // Set Tab Listeners
    Tab1.setTabListener(new TabListener(fragmentTab1));
    Tab2.setTabListener(new TabListener(fragmentTab2));
    Tab3.setTabListener(new TabListener(fragmentTab3));

    // Add tabs to actionbar
    actionBar.addTab(Tab1);
    actionBar.addTab(Tab2);
    actionBar.addTab(Tab3);




    txtArduino = (TextView) findViewById(R.id.txtArduino);

    button1 = (Button)findViewById(R.id.button1);

    button1.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v){
        //Creating popupmenu
        PopupMenu popup = new PopupMenu(MainActivity.this, button1);
        //inflating the popup menu
        popup.getMenuInflater().inflate(R.menu.popup_menu, popup.getMenu());

        //register popup with onMenuItemClickListener
        popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
            public boolean onMenuItemClick(MenuItem item) {
                switch(item.getItemId()){
                case R.id.btturnon:
                    if(!btAdapter.isEnabled()){
                    Intent turnOn = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                    startActivityForResult(turnOn, 0);
                    }
                    break;
                case R.id.btconnect:
                    //Connect to known address
                    try{
                        bs =bd.createInsecureRfcommSocketToServiceRecord
(UUID.fromString("00001101-0000-1000-8000-    00805F9B34FB"));
                    }
                    catch(IOException io){
                        Toast.makeText(getApplicationContext(), "Socket Create : " +
 io.toString() , Toast.LENGTH_SHORT).show();
                    }
                    try{
                        btAdapter.cancelDiscovery();
                        bs.connect();
                        mmOutputStream = bs.getOutputStream();
                        mmInputStream = bs.getInputStream();
                    }
                    catch(IOException io){
                        Log.e("Socket Connect", io.toString());
                        Toast.makeText(getApplicationContext(), "Socket Connect : " +
io.toString() , Toast.LENGTH_LONG).show();
                    }
                    beginListenForData();
                    txtArduino.setText("Bluetooth channel Openned");
                    break;
                }
                //Toast.makeText(MainActivity.this,  "You Clicked : " + item.getTitle(), 
Toast.LENGTH_SHORT).show();
                return true;
            }
        });
        popup.show();// shows the popup menu
    }
    });
  }
 void beginListenForData(){   
final Handler handler = new Handler();
final byte delimiter = 10;
stopWorker = false;
readBufferPosition = 0;
readBuffer = new byte[1024];
workerThread = new Thread(new Runnable()
{
    public void run()
    {

        while(!Thread.currentThread().isInterrupted() && !stopWorker)
        {
            try
            {

                int bytesAvailable = mmInputStream.available();
                if(bytesAvailable >0)
                    {
                    byte[] packetBytes = new byte[bytesAvailable];
                    mmInputStream.read(packetBytes);
                    for(int i = 0; i<bytesAvailable;i++){
                        byte b = packetBytes[i];
                        if(b == delimiter)
                        {
                            byte[] encodedBytes = new byte[readBufferPosition];
                            System.arraycopy(readBuffer, 0, encodedBytes, 0, 
encodedBytes.length);
                            final String data = new String(encodedBytes, "US-ASCII");
                            readBufferPosition = 0;
                            handler.post(new Runnable() {
                                public void run(){
                                    txtArduino.setText(data);
                                    onPassToFragment(data);

                                }
                            });
                            }
                        else {
                            readBuffer[readBufferPosition++]=b;
                            }
                        }
                    }
                } catch (IOException ex) {
                    stopWorker = true;
                }
            }
        }
    });
workerThread.start();
}
void closeBT() throws IOException {
    stopWorker = true;
    mmOutputStream.close();
    mmInputStream.close();
    bs.close();
    txtArduino.setText("Bluetooth Closed");
}

public void onPassToFragment(String string){
    if(fragmentCommunicator != null){
        fragmentCommunicator.passDataToFragment(string);
    }
}
}

我的片段：

public class FragmentTab2 extends Fragment implements FragmentCommunicator {
private TextView graphsForce;
private String graphs="Nothing yet";
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment2, container, false);
    graphsForce = (TextView) rootView.findViewById(R.id.graphs);
    return rootView;
}
public void passDataToFragment(String someValue){
    graphs = someValue;
    graphsForce.setText(graphs);
}
}

接口FragmentCommunicator：

package com.example.eightcount;

public interface FragmentCommunicator {
public void passDataToFragment(String someValue);
}

.xml fragment2：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/fragment2" >

<TextView
    android:id="@+id/graphs"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="@string/graphs" 
     />

</RelativeLayout>

对此的任何帮助都将非常感激，我已经挂了好几天了。

谢谢！

Answer 1

fragmentCommunicator为null，它永远不会被设置。

也许你可以直接在片段上调用它：fragmentTab2.passDataToFragment(String)

不会从活动中调用Fragment方法

1 个答案: