Java 屏幕锁定后相机冻结
我正在为Android开发一个使用zbar的条形码扫描仪。 一切正常。但是，当我的应用程序进入睡眠状态或手机锁定时，相机预览会被冻结，我无法在恢复时重新启动它 fragment.javaJava 屏幕锁定后相机冻结,java,android,android-camera,Java,Android,Android Camera,我正在为Android开发一个使用zbar的条形码扫描仪。 一切正常。但是，当我的应用程序进入睡眠状态或手机锁定时，相机预览会被冻结，我无法在恢复时重新启动它 fragment.java package com.alsafeer.xpressions.fragment; import android.graphics.Typeface; import android.hardware.Camera; import android.os.AsyncTask; import android.os.
package com.alsafeer.xpressions.fragment;
import android.graphics.Typeface;
import android.hardware.Camera;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.alsafeer.xpressions.AnalyticsSampleApp;
import com.alsafeer.xpressions.CameraPreview;
import com.alsafeer.xpressions.JsonParser;
import com.alsafeer.xpressions.R;
import com.google.android.gms.analytics.GoogleAnalytics;
import com.google.android.gms.analytics.HitBuilders;
import com.google.android.gms.analytics.Tracker;
import net.sourceforge.zbar.Config;
import net.sourceforge.zbar.Image;
import net.sourceforge.zbar.ImageScanner;
import net.sourceforge.zbar.Symbol;
import net.sourceforge.zbar.SymbolSet;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class rewards extends Fragment {
private Camera mCamera;
private CameraPreview mPreview;
private Handler autoFocusHandler;
private String Name;
private String Email;
private View view;
private String Mob;
private String Points;
private String result;
private RelativeLayout preview;
TextView scanText;
Button scanButton;
ImageScanner scanner;
private boolean barcodeScanned = false;
private boolean previewing = true;
static {
System.loadLibrary("iconv");
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
setHasOptionsMenu(true);
view = inflater.inflate(R.layout.activity_rewards,
container, false);
view.setFocusableInTouchMode(true);
view.requestFocus();
Tracker t = ((AnalyticsSampleApp) getActivity().getApplication()).getTracker(
AnalyticsSampleApp.TrackerName.APP_TRACKER);
GoogleAnalytics.getInstance(getActivity()).setLocalDispatchPeriod(1);
t.setScreenName("Rewards Barcode Reader");
t.send(new HitBuilders.AppViewBuilder().build());
Typeface font = Typeface.createFromAsset(getActivity().getAssets(), "fonts/font.ttf");
Button next= (Button) view.findViewById(R.id.next);
next.setTypeface(font);
scanText = (EditText)view.findViewById(R.id.editText6);
scanText.setTypeface(font);
mCamera = getCameraInstance();
getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE|
WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);
next.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(!scanText.getText().toString().equals(""))
{
new AsyncTaskParseJson().execute();
}
else
{
Toast.makeText(getActivity(),"Please enter the number or scan the barcode...", Toast.LENGTH_LONG).show();
}
}
});
scanText.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
releaseCamera();
getFragmentManager().beginTransaction().replace(R.id.content_frame, new FirstFragment(), "first").commit();
return true;
}
}
return false;
}
});
view.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
releaseCamera();
getFragmentManager().beginTransaction().replace(R.id.content_frame, new FirstFragment(), "first").commit();
return true;
}
}
return true;
}
});
autoFocusHandler = new Handler();
/* Instance barcode scanner */
scanner = new ImageScanner();
scanner.setConfig(0, Config.X_DENSITY, 3);
scanner.setConfig(0, Config.Y_DENSITY, 3);
mPreview = new CameraPreview(getActivity(), mCamera, previewCb, autoFocusCB);
preview = (RelativeLayout) view.findViewById(R.id.cameraPreview);
preview.addView(mPreview);
scanButton = (Button)view.findViewById(R.id.button6);
scanButton.setTypeface(font);
scanButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (barcodeScanned) {
barcodeScanned = false;
mCamera.setPreviewCallback(previewCb);
mCamera.startPreview();
previewing = true;
mCamera.autoFocus(autoFocusCB);
}
}
});
return view;
}
@Override
public void onResume() {
super.onResume();
if(mCamera==null) {
mCamera=getCameraInstance();
mPreview = new CameraPreview(getActivity(), mCamera, previewCb, autoFocusCB);
preview = (RelativeLayout) view.findViewById(R.id.cameraPreview);
preview.addView(mPreview);
mCamera.setPreviewCallback(previewCb);
mCamera.startPreview();
previewing = true;
mCamera.autoFocus(autoFocusCB);
}
}
@Override
public void onPause() {
super.onPause();
}
@Override
public void onStop() {
super.onStop();
releaseCamera();
}
/** A safe way to get an instance of the Camera object. */
public static Camera getCameraInstance(){
Camera c = null;
try {
c = Camera.open();
} catch (Exception e){
}
return c;
}
public void releaseCamera() {
if (mCamera != null) {
previewing = false;
mCamera.setPreviewCallback(null);
mCamera.release();
mCamera = null;
}
}
private Runnable doAutoFocus = new Runnable() {
public void run() {
if (previewing)
mCamera.autoFocus(autoFocusCB);
}
};
Camera.PreviewCallback previewCb = new Camera.PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
Camera.Parameters parameters = camera.getParameters();
Camera.Size size = parameters.getPreviewSize();
Image barcode = new Image(size.width, size.height, "Y800");
barcode.setData(data);
int result = scanner.scanImage(barcode);
if (result != 0) {
previewing = false;
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
SymbolSet syms = scanner.getResults();
for (Symbol sym : syms) {
scanText.setText(sym.getData());
barcodeScanned = true;
}
}
}
};
// Mimic continuous auto-focusing
Camera.AutoFocusCallback autoFocusCB = new Camera.AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
autoFocusHandler.postDelayed(doAutoFocus, 1000);
}
};
public class AsyncTaskParseJson extends AsyncTask<String, String, String> {
JSONArray dataJsonArr = null;
@Override
protected void onPreExecute() {}
@Override
protected String doInBackground(String... arg0) {
try {
// instantiate our json parser
JsonParser jParser = new JsonParser();
// get json string from url
JSONObject json = jParser.getJSONFromUrl("http://www.safeerplus.ae/ncno="+scanText.getText().toString());
// get the array of users
dataJsonArr = json.getJSONArray("msg");
// loop through all users
JSONObject c = dataJsonArr.getJSONObject(0);
// Storing each json item in variable
Name = c.getString("name");
Mob = c.getString("mob");
Email = c.getString("email");
Points = c.getString("points");
if(Name.equals("")||Mob.equals("")||Email.equals("")||Points.equals(""))
{
}
else {
Bundle args = new Bundle();
args.putString("code", scanText.getText().toString());
args.putString("name1", Name);
args.putString("mob1", Mob);
args.putString("email1", Email);
args.putString("points1", Points);
releaseCamera();
Fragment fr=new reward_details();
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
fr.setArguments(args);
ft.replace(R.id.content_frame, fr);
ft.commit();
}
} catch (JSONException e) {
getActivity().runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(getActivity(), "Please use a valid card!", Toast.LENGTH_LONG).show();
}
});
}
return null;
}
@Override
protected void onPostExecute(String strFromDoInBg) {}
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"
android:background="#e7e7e9">
<RelativeLayout
android:id="@+id/cameraPreview"
android:layout_width="300dp"
android:layout_height="300dp"
android:layout_weight="1"
android:gravity="clip_horizontal"
android:layout_below="@+id/editText6"
android:layout_centerHorizontal="true">
</RelativeLayout>
<Button
android:id="@+id/next"
android:text="View points"
android:layout_width="120dp"
android:layout_height="30sp"
android:layout_gravity="center"
android:background="@drawable/loginbutton"
android:textSize="12sp"
android:layout_alignTop="@+id/button6"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<Button
android:id="@+id/button6"
android:text="Rescan"
android:layout_width="120dp"
android:layout_height="30sp"
android:layout_gravity="center"
android:background="@drawable/loginbutton"
android:textSize="12sp"
android:layout_below="@+id/cameraPreview"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginTop="30dp" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="number"
android:ems="10"
android:id="@+id/editText6"
android:background="#d1d2d4"
android:textSize="15sp"
android:padding="5dp"
android:textColor="#000000"
android:hint="Enter or Scan the Barcode"
android:textColorHint="#4a4f5a"
android:layout_alignParentTop="true"
android:layout_alignLeft="@+id/cameraPreview"
android:layout_alignStart="@+id/cameraPreview"
android:layout_alignRight="@+id/cameraPreview"
android:layout_alignEnd="@+id/cameraPreview" />
</RelativeLayout>