Question

我试图通过蓝牙从两个不同的活动发送数据。但我没有成功。这是我的代码：

 public class MainActivity extends Activity {

private BluetoothDevice btDevice;
private CommunicationThread cmThread = null;


TextView y;
    private static final UUID sppUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");


Button  activityci, dato1;
TextView texto;
int count=0; 

@Override
   public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    activityci=(Button)findViewById(R.id.idboton);
    texto=(TextView)findViewById(R.id.idtexto);

    activityci.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent comenzarPrincipal = new Intent(getBaseContext(), SegundoActivity.class);

            startActivity(comenzarPrincipal);


            cmThread.write((char)120);





        }
    });


    this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

    Intent startIntent = this.getIntent();
    String btDevAddress = startIntent.getStringExtra(BuscarDispositivos.EXTRA_DEV_ADDRESS);

    btDevice = BluetoothAdapter.getDefaultAdapter().getRemoteDevice(btDevAddress);

    BluetoothSocket btSocket = null;
    try 
    {
                    btSocket = btDevice.createRfcommSocketToServiceRecord(sppUUID);
        cmThread = new CommunicationThread(btSocket);
        cmThread.start();

    } 
    catch (Exception e) 
    {
        Toast.makeText(this, "Necesita Conectarse!", Toast.LENGTH_SHORT).show();
        finish();
        return;
    }
}


}]

</i>

我的第二项活动：

      public class SegundoActivity extends Activity {
private CommunicationThread cmthread=null;
Button btn2;
TextView text2;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.prueba2);

    btn2=(Button)findViewById(R.id.idboton2);
    text2=(TextView)findViewById(R.id.idtexto2);

    btn2.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            int dato=250;
            char data=(char)dato;
            text2.setText(""+dato);

            cmthread.write(data);



        }
    });



}


 }

从第一个活动开始，我可以通过蓝牙发送数据。但是当我从第二个活动发送时，我得到错误。有人知道这段代码有什么问题吗？

Answer 1

好的，首先你可以创建一个ViewFlipper。然后，您不需要创建新的Activity，只需要一个新的布局。如果你这样做，你就不会遇到必须从另一个活动中发送它的问题。

我在这里举个例子：

<强> main_layout.xml ：

<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:background="#333333">

<ViewFlipper
    android:id="@+id/viewFlipper1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

     <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button" />

    </RelativeLayout>

   <include android:id="@+id/secondActivity" layout="@layout/second_layout"/>

   </ViewFlipper>

</RelativeLayout>

<强> second_layout.xml ：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/secondActivity"
android:layout_width="match_parent"
android:layout_height="match_parent" 
 android:background="#333333">

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true" >

    <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Button" />


</RelativeLayout>

</RelativeLayout>

<强> YourActivity.java ：

OnCreate中：

ViewFlipper viewFlipper = (ViewFlipper) this.findViewById(R.id.viewFlipper1);

Button btn1=(Button)findViewById(R.id.button1);

btn1.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View v) {

       // Here you go in the next layout
       YourActivity.this.viewFlipper.showNext();

    }
});

如果你这样做，我保证你不会因为蓝牙而崩溃。

通过蓝牙从两个不同的活动发送数据

1 个答案: