将setContentView（R.layout.main）移到Broadcast接收器类

Question

I have a mUsbReceiver ( BroadcastReceiver ) and CameraActivity . The receiver setContentView(R.layout.main) from CameraActivity via an Intent . Then CamearActivity updates its View with this value. Notice that the setContentView is in the Broadcast receiver class and not in the CameraActivity Class.

public class CameraActivity extends Activity {

private static final String TAG = "openXC::Activity";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);     
    usbConnection();

}

public void usbConnection() {
    UsbManager mUsbManager = (UsbManager) getSystemService(Context.USB_SERVICE);


   PendingIntent mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), PendingIntent.FLAG_CANCEL_CURRENT);
    IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
   registerReceiver(mUsbReceiver, filter);
    String txt = "default";
    HashMap<String, UsbDevice> deviceList = mUsbManager.getDeviceList();
    Log.i(TAG, "Device List: " + deviceList);
    Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
    UsbDevice device = deviceIterator.next();
    Log.i(TAG, "Device List: " + deviceList);
    mUsbManager.requestPermission(device, mPermissionIntent);
}

private static final String ACTION_USB_PERMISSION ="com.ford.openxc.webcam.USB_PERMISSION";
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {

    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (ACTION_USB_PERMISSION.equals(action)) {
            synchronized (this) {
                UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);

                if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
                    if(device != null){
                        Log.d(TAG, "Displayed Comten View " + device);
                        setContentView(R.layout.main);

                   }
                } 
                else {
                    Log.d(TAG, "permission denied for device " + device);
                }
            }
        }
    }
 };
}

This works fine sometimes but sometimes throws the following error

I/openXC::Activity( 5609): Device List: {/dev/bus/usb/001/002=UsbDevice[mName=/dev/bus/usb/001/002,mVendorId=1133,mProductId=2085,mClass=239,mSubclass=2,mProtocol=1,mInterfaces=[Landroid.os.Parcelable;@421a1f50]}
I/openXC::Activity( 5609): Device List: {/dev/bus/usb/001/002=UsbDevice[mName=/dev/bus/usb/001/002,mVendorId=1133,mProductId=2085,mClass=239,mSubclass=2,mProtocol=1,mInterfaces=[Landroid.os.Parcelable;@421a1f50]}
I/Adreno200-EGLSUB( 5609): <ConfigWindowMatch:2087>: Format RGBA_8888.
E/        ( 5609): <s3dReadConfigFile:75>: Can't open file for reading
E/        ( 5609): <s3dReadConfigFile:75>: Can't open file for reading
D/openXC::Activity( 5609): Displayed Comten View UsbDevice[mName=/dev/bus/usb/001/002,mVendorId=1133,mProductId=2085,mClass=239,mSubclass=2,mProtocol=1,mInterfaces=[Landroid.os.Parcelable;@421d3ed0]
D/WebcamPreview( 5609): WebcamPreview constructed

Answer 1

Technically, you can call setContentView any time you are executing on the event thread.

Otherwise you need to use a Handler to call it.

Also, here are some usefull links that might help you:

link1

link 2

link 3

Answer 2

I dont have much exp on USB sort of thing but since u said its saying cannot readfile.. i believe dat the error may be in the usb so for the debugging purpose i would suggest to move the setContentView(int) from if conditions to the onRecieve directly so dat whenever the onReceive is called ur contenview will change , this will help to ensure that the error is not with setcontentview... After dat u can see without setcontentview in the usb and now if the error is coming then surely the error is in the usb and not in the setContentView ....

Hope it works :)