我正在为android开发一个条形码扫描器的应用程序。我正在使用zxing library2.2和core 2.2。我使用Google ApI 4.0开发了该应用程序。我在这些文件中收到编译时错误：
HistoryActivity.java
I am getting a compile time error case expression must be constant expresion
@Override
public boolean onOptionsItemSelected(MenuItem item) {
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
switch (item.getItemId()) {
case R.id.menu_share:
intent.setClassName(this, ShareActivity.class.getName());
startActivity(intent);
break;
case R.id.menu_history:
intent.setClassName(this, HistoryActivity.class.getName());
startActivityForResult(intent, HISTORY_REQUEST_CODE);
break;
case R.id.menu_settings:
intent.setClassName(this, PreferencesActivity.class.getName());
startActivity(intent);
break;
case R.id.menu_help:
intent.setClassName(this, HelpActivity.class.getName());
startActivity(intent);
break;
default:
return super.onOptionsItemSelected(item);
}
return true;
}
有人能告诉我如何解决这个问题吗？
答案 0 :(得分：-1)
这是我的CaptureActivity.Java类，没有任何错误和异常。
public final class CaptureActivity extends Activity
implements surfaceHolder.Callback {
// SCAN
private static final String TAG = CaptureActivity.class.getSimpleName();
private static final int HISTORY_ID = Menu.FIRST + 1;
private static final int SETTINGS_ID = Menu.FIRST + 2;
private static final long DEFAULT_INTENT_RESULT_DURATION_MS = 1500L;
private static final long BULK_MODE_SCAN_DELAY_MS = 1000L;
private static final String PACKAGE_NAME = "com.google.zxing.client.android";
private static final String PRODUCT_SEARCH_URL_PREFIX = "http://www.google";
private static final String PRODUCT_SEARCH_URL_SUFFIX = "/m/products/scan";
private static final String[] ZXING_URLS = {
"http://zxing.appspot.com/scan", "zxing://scan/"};
private static final String RETURN_CODE_PLACEHOLDER = "{CODE}";
private static final String RETURN_URL_PARAM = "ret";
private static final Set<ResultMetadataType> DISPLAYABLE_METADATA_TYPES = EnumSet
.of(ResultMetadataType.ISSUE_NUMBER,
ResultMetadataType.SUGGESTED_PRICE,
ResultMetadataType.ERROR_CORRECTION_LEVEL,
ResultMetadataType.POSSIBLE_COUNTRY);
// UPC_EAN_EXTENSION
private CameraManager cameraManager;
private CaptureActivityHandler handler;
private Result savedResultToShow;
private ViewfinderView viewfinderView;
private TextView statusView;
private View resultView;
private Result lastResult;
private boolean hasSurface;
private boolean copyToClipboard;
private IntentSource source;
private String sourceUrl;
private String returnUrlTemplate;
private Collection<BarcodeFormat> decodeFormats;
private String characterSet;
private String versionName;
private HistoryManager historyManager;
private InactivityTimer inactivityTimer;
private BeepManager beepManager;
ViewfinderView getViewfinderView() {
return viewfinderView;
}
public Handler getHandler() {
return handler;
}
CameraManager getCameraManager() {
return cameraManager;
}
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
Window window = getWindow();
window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.capture);
hasSurface = false;
historyManager = new HistoryManager(this);
historyManager.trimHistory();
inactivityTimer = new InactivityTimer(this);
beepManager = new BeepManager(this);
PreferenceManager.setDefaultValues(this, R.xml.preferences, false);
}
@Override
protected void onResume() {
super.onResume();
// CameraManager must be initialized here, not in onCreate(). This is
// necessary because we don't
// want to open the camera driver and measure the screen size if we're
// going to show the help on
// first launch. That led to bugs where the scanning rectangle was the
// wrong size and partially
// off screen.
cameraManager = new CameraManager(getApplication());
viewfinderView = (ViewfinderView) findViewById(R.id.viewfinder_view);
viewfinderView.setCameraManager(cameraManager);
resultView = findViewById(R.id.result_view);
statusView = (TextView) findViewById(R.id.status_view);
handler = null;
lastResult = null;
resetStatusView();
SurfaceView surfaceView = (SurfaceView) findViewById(R.id.preview_view);
SurfaceHolder surfaceHolder = surfaceView.getHolder();
if (hasSurface) {
// The activity was paused but not stopped, so the surface still
// exists. Therefore
// surfaceCreated() won't be called, so init the camera here.
initCamera(surfaceHolder);
} else {
// Install the callback and wait for surfaceCreated() to init the
// camera.
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
beepManager.updatePrefs();
inactivityTimer.onResume();
Intent intent = getIntent();
SharedPreferences prefs = PreferenceManager
.getDefaultSharedPreferences(this);
copyToClipboard = prefs.getBoolean(
PreferencesActivity.KEY_COPY_TO_CLIPBOARD, true)
&& ((intent == null) || intent.getBooleanExtra(
Intents.Scan.SAVE_HISTORY, true));
source = IntentSource.NONE;
decodeFormats = null;
characterSet = null;
if (intent != null) {
String action = intent.getAction();
String dataString = intent.getDataString();
if (Intents.Scan.ACTION.equals(action)) {
// Scan the formats the intent requested, and return the result
// to the calling activity.
source = IntentSource.NATIVE_APP_INTENT;
decodeFormats = DecodeFormatManager.parseDecodeFormats(intent);
if (intent.hasExtra(Intents.Scan.WIDTH)
&& intent.hasExtra(Intents.Scan.HEIGHT)) {
int width = intent.getIntExtra(Intents.Scan.WIDTH, 0);
int height = intent.getIntExtra(Intents.Scan.HEIGHT, 0);
if ((width > 0) && (height > 0)) {
cameraManager.setManualFramingRect(width, height);
}
}
String customPromptMessage = intent
.getStringExtra(Intents.Scan.PROMPT_MESSAGE);
if (customPromptMessage != null) {
statusView.setText(customPromptMessage);
}
} else if ((dataString != null)
&& dataString.contains(PRODUCT_SEARCH_URL_PREFIX)
&& dataString.contains(PRODUCT_SEARCH_URL_SUFFIX)) {
// Scan only products and send the result to mobile Product
// Search.
source = IntentSource.PRODUCT_SEARCH_LINK;
sourceUrl = dataString;
decodeFormats = DecodeFormatManager.PRODUCT_FORMATS;
} else if (isZXingURL(dataString)) {
// Scan formats requested in query string (all formats if none
// specified).
// If a return URL is specified, send the results there.
// Otherwise, handle it ourselves.
source = IntentSource.ZXING_LINK;
sourceUrl = dataString;
Uri inputUri = Uri.parse(sourceUrl);
returnUrlTemplate = inputUri
.getQueryParameter(RETURN_URL_PARAM);
decodeFormats = DecodeFormatManager
.parseDecodeFormats(inputUri);
}
characterSet = intent.getStringExtra(Intents.Scan.CHARACTER_SET);
}
}
private static boolean isZXingURL(String dataString) {
if (dataString == null) {
return false;
}
for (String url : ZXING_URLS) {
if (dataString.startsWith(url)) {
return true;
}
}
return false;
}
@Override
protected void onPause() {
if (handler != null) {
handler.quitSynchronously();
handler = null;
}
inactivityTimer.onPause();
cameraManager.closeDriver();
if (!hasSurface) {
SurfaceView surfaceView = (SurfaceView) findViewById(R.id.preview_view);
SurfaceHolder surfaceHolder = surfaceView.getHolder();
surfaceHolder.removeCallback(this);
}
super.onPause();
}
@Override
protected void onDestroy() {
inactivityTimer.shutdown();
super.onDestroy();
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
if (source == IntentSource.NATIVE_APP_INTENT) {
setResult(RESULT_CANCELED);
finish();
return true;
} else if (((source == IntentSource.NONE) || (source == IntentSource.ZXING_LINK))
&& (lastResult != null)) {
// restartPreviewAfterDelay(0L);
Intent i = new Intent().putExtra("SCAN_RESULT", text);
i.putExtra("SCAN_RESULT_FORMAT", type);
setResult(RESULT_OK, i);
finish();
return true;
}
} else if ((keyCode == KeyEvent.KEYCODE_FOCUS)
|| (keyCode == KeyEvent.KEYCODE_CAMERA)) {
// Handle these events so they don't launch the Camera app
return true;
}
return super.onKeyDown(keyCode, event);
}
/*
* @Override public boolean onCreateOptionsMenu(Menu menu) {
* super.onCreateOptionsMenu(menu); menu.add(Menu.NONE, HISTORY_ID,
* Menu.NONE, R.string.menu_history)
* .setIcon(android.R.drawable.ic_menu_recent_history); menu.add(Menu.NONE,
* SETTINGS_ID, Menu.NONE, R.string.menu_settings)
* .setIcon(android.R.drawable.ic_menu_preferences); return true; }
*
* @Override public boolean onOptionsItemSelected(MenuItem item) { Intent
* intent = new Intent(Intent.ACTION_VIEW);
* intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET); switch
* (item.getItemId()) { case HISTORY_ID : intent = new
* Intent(Intent.ACTION_VIEW);
* intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
* intent.setClassName(this, HistoryActivity.class.getName());
* startActivity(intent); break; case SETTINGS_ID :
* intent.setClassName(this, PreferencesActivity.class.getName());
* startActivity(intent); break; default : return
* super.onOptionsItemSelected(item); } return true; }
*/
private void decodeOrStoreSavedBitmap(Bitmap bitmap,
com.google.zxing.Result result) {
// Bitmap isn't used yet -- will be used soon
if (handler == null) {
savedResultToShow = result;
} else {
if (result != null) {
savedResultToShow = result;
}
if (savedResultToShow != null) {
Message message = Message.obtain(handler,
R.id.decode_succeeded, savedResultToShow);
handler.sendMessage(message);
}
savedResultToShow = null;
}
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
if (holder == null) {
Log.e(TAG,
"*** WARNING *** surfaceCreated() gave us a null surface!");
}
if (!hasSurface) {
hasSurface = true;
initCamera(holder);
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
hasSurface = false;
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
}
/**
* A valid barcode has been found, so give an indication of success and show
* the results.
*
* @param rawResult
* The contents of the barcode.
* @param barcode
* A greyscale bitmap of the camera data which was decoded.
*/
public void handleDecode(Result rawResult, Bitmap barcode) {
inactivityTimer.onActivity();
lastResult = rawResult;
ResultHandler resultHandler = ResultHandlerFactory.makeResultHandler(
this, rawResult);
historyManager.addHistoryItem(rawResult, resultHandler);
if (barcode == null) {
// This is from history -- no saved barcode
handleDecodeInternally(rawResult, resultHandler, null);
} else {
beepManager.playBeepSoundAndVibrate();
drawResultPoints(barcode, rawResult);
switch (source) {
case NATIVE_APP_INTENT :
case PRODUCT_SEARCH_LINK :
handleDecodeExternally(rawResult, resultHandler, barcode);
break;
case ZXING_LINK :
if (returnUrlTemplate == null) {
handleDecodeInternally(rawResult, resultHandler,
barcode);
} else {
handleDecodeExternally(rawResult, resultHandler,
barcode);
}
break;
case NONE :
SharedPreferences prefs = PreferenceManager
.getDefaultSharedPreferences(this);
if (prefs.getBoolean(PreferencesActivity.KEY_BULK_MODE,
false)) {
Toast.makeText(this, R.string.msg_bulk_mode_scanned,
Toast.LENGTH_SHORT).show();
// Wait a moment or else it will scan the same barcode
// continuously about 3 times
restartPreviewAfterDelay(BULK_MODE_SCAN_DELAY_MS);
} else {
handleDecodeInternally(rawResult, resultHandler,
barcode);
}
break;
}
}
}
/**
* Superimpose a line for 1D or dots for 2D to highlight the key features of
* the barcode.
*
* @param barcode
* A bitmap of the captured image.
* @param rawResult
* The decoded results which contains the points to draw.
*/
private void drawResultPoints(Bitmap barcode, Result rawResult) {
ResultPoint[] points = rawResult.getResultPoints();
if ((points != null) && (points.length > 0)) {
Canvas canvas = new Canvas(barcode);
Paint paint = new Paint();
paint
.setColor(getResources().getColor(
R.color.result_image_border));
paint.setStrokeWidth(3.0f);
paint.setStyle(Paint.Style.STROKE);
Rect border = new Rect(2, 2, barcode.getWidth() - 2, barcode
.getHeight() - 2);
canvas.drawRect(border, paint);
paint.setColor(getResources().getColor(R.color.result_points));
if (points.length == 2) {
paint.setStrokeWidth(4.0f);
drawLine(canvas, paint, points[0], points[1]);
} else if ((points.length == 4)
&& ((rawResult.getBarcodeFormat() == BarcodeFormat.UPC_A) || (rawResult
.getBarcodeFormat() == BarcodeFormat.EAN_13))) {
// Hacky special case -- draw two lines, for the barcode and
// metadata
drawLine(canvas, paint, points[0], points[1]);
drawLine(canvas, paint, points[2], points[3]);
} else {
paint.setStrokeWidth(10.0f);
for (ResultPoint point : points) {
canvas.drawPoint(point.getX(), point.getY(), paint);
}
}
}
}
private static void drawLine(Canvas canvas, Paint paint, ResultPoint a,
ResultPoint b) {
canvas.drawLine(a.getX(), a.getY(), b.getX(), b.getY(), paint);
}
String text, type;
// Put up our own UI for how to handle the decoded contents.
private void handleDecodeInternally(Result rawResult,
ResultHandler resultHandler, Bitmap barcode) {
statusView.setVisibility(View.GONE);
viewfinderView.setVisibility(View.GONE);
resultView.setVisibility(View.VISIBLE);
ImageView barcodeImageView = (ImageView) findViewById(R.id.barcode_image_view);
if (barcode == null) {
barcodeImageView.setImageBitmap(BitmapFactory.decodeResource(
getResources(), R.drawable.launcher_icon));
} else {
barcodeImageView.setImageBitmap(barcode);
}
TextView formatTextView = (TextView) findViewById(R.id.format_text_view);
formatTextView.setText(rawResult.getBarcodeFormat().toString());
TextView typeTextView = (TextView) findViewById(R.id.type_text_view);
typeTextView.setText(resultHandler.getType().toString());
DateFormat formatter = DateFormat.getDateTimeInstance(DateFormat.SHORT,
DateFormat.SHORT);
String formattedTime = formatter.format(new Date(rawResult
.getTimestamp()));
TextView timeTextView = (TextView) findViewById(R.id.time_text_view);
timeTextView.setText(formattedTime);
TextView metaTextView = (TextView) findViewById(R.id.meta_text_view);
View metaTextViewLabel = findViewById(R.id.meta_text_view_label);
metaTextView.setVisibility(View.GONE);
metaTextViewLabel.setVisibility(View.GONE);
Map<ResultMetadataType, Object> metadata = rawResult
.getResultMetadata();
if (metadata != null) {
StringBuilder metadataText = new StringBuilder(20);
for (Map.Entry<ResultMetadataType, Object> entry : metadata
.entrySet()) {
if (DISPLAYABLE_METADATA_TYPES.contains(entry.getKey())) {
metadataText.append(entry.getValue()).append('\n');
}
}
// ResultMetadataType
if (metadataText.length() > 0) {
metadataText.setLength(metadataText.length() - 1);
metaTextView.setText(metadataText);
metaTextView.setVisibility(View.VISIBLE);
metaTextViewLabel.setVisibility(View.VISIBLE);
}
}
TextView contentsTextView = (TextView) findViewById(R.id.contents_text_view);
CharSequence displayContents = resultHandler.getDisplayContents();
contentsTextView.setText(displayContents);
text = displayContents.toString();
type = formatTextView.getText().toString();
// Crudely scale betweeen 22 and 32 -- bigger font for shorter text
int scaledSize = Math.max(22, 32 - displayContents.length() / 4);
contentsTextView.setTextSize(TypedValue.COMPLEX_UNIT_SP, scaledSize);
TextView supplementTextView = (TextView) findViewById(R.id.contents_supplement_text_view);
supplementTextView.setText("");
supplementTextView.setOnClickListener(null);
if (PreferenceManager.getDefaultSharedPreferences(this).getBoolean(
PreferencesActivity.KEY_SUPPLEMENTAL, true)) {
SupplementalInfoRetriever.maybeInvokeRetrieval(supplementTextView,
resultHandler.getResult(), handler, historyManager, this);
}
if (copyToClipboard && !resultHandler.areContentsSecure()) {
ClipboardManager clipboard = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
clipboard.setText(displayContents);
}
}
// Briefly show the contents of the barcode, then handle the result outside
// Barcode Scanner.
private void handleDecodeExternally(Result rawResult,
ResultHandler resultHandler, Bitmap barcode) {
viewfinderView.drawResultBitmap(barcode);
// Since this message will only be shown for a second, just tell the
// user what kind of
// barcode was found (e.g. contact info) rather than the full contents,
// which they won't
// have time to read.
statusView.setText(getString(resultHandler.getDisplayTitle()));
if (copyToClipboard && !resultHandler.areContentsSecure()) {
ClipboardManager clipboard = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
clipboard.setText(resultHandler.getDisplayContents());
}
if (source == IntentSource.NATIVE_APP_INTENT) {
// Hand back whatever action they requested - this can be changed to
// Intents.Scan.ACTION when
// the deprecated intent is retired.
Intent intent = new Intent(getIntent().getAction());
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
intent.putExtra(Intents.Scan.RESULT, rawResult.toString());
intent.putExtra(Intents.Scan.RESULT_FORMAT, rawResult
.getBarcodeFormat().toString());
byte[] rawBytes = rawResult.getRawBytes();
if ((rawBytes != null) && (rawBytes.length > 0)) {
intent.putExtra(Intents.Scan.RESULT_BYTES, rawBytes);
}
Map<ResultMetadataType, ?> metadata = rawResult.getResultMetadata();
if (metadata != null) {
Integer orientation = (Integer) metadata
.get(ResultMetadataType.ORIENTATION);
if (orientation != null) {
intent.putExtra(Intents.Scan.RESULT_ORIENTATION,
orientation.intValue());
}
String ecLevel = (String) metadata
.get(ResultMetadataType.ERROR_CORRECTION_LEVEL);
if (ecLevel != null) {
intent.putExtra(Intents.Scan.RESULT_ERROR_CORRECTION_LEVEL,
ecLevel);
}
Iterable<byte[]> byteSegments = (Iterable<byte[]>) metadata
.get(ResultMetadataType.BYTE_SEGMENTS);
if (byteSegments != null) {
int i = 0;
for (byte[] byteSegment : byteSegments) {
intent.putExtra(
Intents.Scan.RESULT_BYTE_SEGMENTS_PREFIX + i,
byteSegment);
i++;
}
}
}
sendReplyMessage(R.id.return_scan_result, intent);
} else if (source == IntentSource.PRODUCT_SEARCH_LINK) {
// Reformulate the URL which triggered us into a query, so that the
// request goes to the same
// TLD as the scan URL.
int end = sourceUrl.lastIndexOf("/scan");
String replyURL = sourceUrl.substring(0, end) + "?q="
+ resultHandler.getDisplayContents() + "&source=zxing";
sendReplyMessage(R.id.launch_product_query, replyURL);
} else if (source == IntentSource.ZXING_LINK) {
// Replace each occurrence of RETURN_CODE_PLACEHOLDER in the
// returnUrlTemplate
// with the scanned code. This allows both queries and REST-style
// URLs to work.
if (returnUrlTemplate != null) {
String codeReplacement = String.valueOf(resultHandler
.getDisplayContents());
try {
codeReplacement = URLEncoder.encode(codeReplacement,
"UTF-8");
} catch (UnsupportedEncodingException e) {
// can't happen; UTF-8 is always supported. Continue, I
// guess, without encoding
}
String replyURL = returnUrlTemplate.replace(
RETURN_CODE_PLACEHOLDER, codeReplacement);
sendReplyMessage(R.id.launch_product_query, replyURL);
}
}
}
private void sendReplyMessage(int id, Object arg) {
Message message = Message.obtain(handler, id, arg);
long resultDurationMS = getIntent().getLongExtra(
Intents.Scan.RESULT_DISPLAY_DURATION_MS,
DEFAULT_INTENT_RESULT_DURATION_MS);
if (resultDurationMS > 0L) {
handler.sendMessageDelayed(message, resultDurationMS);
} else {
handler.sendMessage(message);
}
}
/**
* We want the help screen to be shown automatically the first time a new
* version of the app is run. The easiest way to do this is to check
* android:versionCode from the manifest, and compare it to a value stored
* as a preference.
*/
private void initCamera(SurfaceHolder surfaceHolder) {
try {
cameraManager.openDriver(surfaceHolder);
// Creating the handler starts the preview, which can also throw a
// RuntimeException.
if (handler == null) {
handler = new CaptureActivityHandler(this, decodeFormats,
characterSet, cameraManager);
}
decodeOrStoreSavedBitmap(null, null);
} catch (IOException ioe) {
Log.w(TAG, ioe);
displayFrameworkBugMessageAndExit();
} catch (RuntimeException e) {
// Barcode Scanner has seen crashes in the wild of this variety:
// java.?lang.?RuntimeException: Fail to connect to camera service
Log.w(TAG, "Unexpected error initializing camera", e);
displayFrameworkBugMessageAndExit();
}
}
private void displayFrameworkBugMessageAndExit() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle(getString(R.string.app_name));
builder.setMessage(getString(R.string.msg_camera_framework_bug));
builder.setPositiveButton(R.string.button_ok, new FinishListener(this));
builder.setOnCancelListener(new FinishListener(this));
builder.show();
}
public void restartPreviewAfterDelay(long delayMS) {
if (handler != null) {
handler.sendEmptyMessageDelayed(R.id.restart_preview, delayMS);
}
resetStatusView();
}
private void resetStatusView() {
resultView.setVisibility(View.GONE);
statusView.setText(R.string.msg_default_status);
statusView.setVisibility(View.VISIBLE);
viewfinderView.setVisibility(View.VISIBLE);
lastResult = null;
}
public void drawViewfinder() {
viewfinderView.drawViewfinder();
}
/*@Override
public void onBackPressed() {
// TODO Auto-generated method stub
shopping.txtv_no_qr_code_scan.setVisibility(TextView.VISIBLE);
super.onBackPressed();
}*/
}