频闪灯不能正常工作

时间：2014-04-04 06:59:38

标签： java android flashlight

我已经为各种来源的闪光灯编写了代码，但问题是它无法正常工作。这是代码：

StrobeLight.java 

import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.hardware.Camera;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ToggleButton;

 public class StrobeLight extends Activity implements OnClickListener
   {
    Button button;
    Camera cam;
    StrobeRunner runner;
    Thread bw;

    public final Handler mHandler = new Handler();

    public final Runnable mShowToastRunnable = new Runnable() {
        public void run() {
            showMessage();
        }
    };



    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.strobelight); 
        final ToggleButton togglebutton = (ToggleButton) findViewById(R.id.ToggleButton01);

        button=(Button)findViewById(R.id.power);

        runner = StrobeRunner.getInstance();
        runner.controller = this;

        if(runner.isRunning)
        {   

        }
        else
        {
            try
            {

                cam = Camera.open();

                if(cam==null)
                {
                    togglebutton.setEnabled(false);
                    TextView t = (TextView)findViewById(R.id.TextView01);
                    t.setText(R.string.nocamera);
                    return;
                }

                cam.release();
            }
            catch(RuntimeException ex)
            {
                togglebutton.setEnabled(false);
                TextView t = (TextView)findViewById(R.id.TextView01);
                t.setText(R.string.nocamera);
                Toast.makeText(getApplicationContext(), "Error connecting to camera flash.", Toast.LENGTH_LONG).show();
                return;
            }
        } 


        togglebutton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                // Perform action on clicks
                if (togglebutton.isChecked()) {
                    bw = new Thread(runner);
                    bw.start();
                } else {
                    runner.requestStop = true;
                }
            }
        });

        final SeekBar skbar = (SeekBar)findViewById(R.id.SeekBar01);
        skbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress,
                    boolean fromUser) {
                runner.delay=progress;

            }
        });

        final SeekBar skbaroff = (SeekBar)findViewById(R.id.SeekBar02);
        skbaroff.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress,
                    boolean fromUser) {
                runner.delayoff=progress;

            }
        });


    }

    @Override
    protected void onStop() {
        runner.requestStop=true;
        ToggleButton togglebutton = (ToggleButton) findViewById(R.id.ToggleButton01);
        togglebutton.setChecked(false);

        super.onStop();
    }

    public void showMessage()
    {
        String err = runner.errorMessage;
        runner.errorMessage="";
        if(!err.equals(""))
        {
            Context context = getApplicationContext();
            int duration = Toast.LENGTH_SHORT;

            Toast toast = Toast.makeText(context, err, duration);
            toast.show();
        }

        ToggleButton togglebutton = (ToggleButton) findViewById(R.id.ToggleButton01);
        togglebutton.setChecked(false);
    }

StrobeRunner.java 

public class StrobeRunner implements Runnable {

    protected StrobeRunner()
    {

    }

    public static StrobeRunner getInstance()
    {
        return ( instance == null ? instance = new StrobeRunner() : instance );
    }

    private static StrobeRunner instance;


    public volatile boolean requestStop = false;
    public volatile boolean isRunning = false;
    public volatile int delay = 10;
    public volatile int delayoff = 500;
    public volatile StrobeLight controller;
    public volatile String errorMessage = "";

    @Override
    public void run() {
        if(isRunning)
            return;

        requestStop=false;
        isRunning = true;

        Camera cam = Camera.open();

        Camera.Parameters pon = cam.getParameters(), poff = cam.getParameters();

        pon.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
        poff.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);

        while(!requestStop)
        {
            try{
                cam.setParameters(pon);
                Thread.sleep(delay);
                cam.setParameters(poff);
                Thread.sleep(delayoff);
            }
            catch(InterruptedException ex)
            {

            }
            catch(RuntimeException ex)
            {
                requestStop = true;
                errorMessage = "Error setting camera flash status. Your device may be unsupported.";
            }
        }

        cam.release();

        isRunning = false;
        requestStop=false;

        controller.mHandler.post(controller.mShowToastRunnable);
    }

}

StrobeLight.xml（布局） 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/SmugeBlue"
    android:orientation="vertical" >

    <com.google.ads.AdView
        xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
        android:id="@+id/ad"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        ads:adSize="SMART_BANNER"
        ads:adUnitId="a15332ae6427e75" />

    <TableRow
        android:id="@+id/tableRow1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingTop="5dp"
        android:layout_below="@id/ad" >

        <TextView
            android:id="@+id/TextView01"
            android:layout_width="wrap_content"
            android:paddingLeft="5dp"
            android:textColor="@color/Yellow1"
            android:text="@string/speedon" >
        </TextView>
    </TableRow>

    <TableRow
        android:id="@+id/tableRow2"
        android:layout_below="@id/tableRow1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" >

        <SeekBar
            android:id="@+id/SeekBar01"
            android:layout_width="fill_parent"
            android:max="10"
            android:paddingLeft="5dp"
            android:paddingRight="5dp"
            android:progress="1" >
        </SeekBar>
    </TableRow>

    <TableRow
        android:id="@+id/tableRow3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/tableRow2"
        android:paddingTop="5dp" >

        <TextView
            android:id="@+id/TextView03"
            android:layout_width="wrap_content"
            android:paddingLeft="5dp"
            android:textColor="@color/Yellow1"
            android:text="@string/speedoff" >
        </TextView>
    </TableRow>

    <TableRow
        android:id="@+id/tableRow4"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/tableRow3" >

        <SeekBar
            android:id="@+id/SeekBar02"
            android:layout_width="fill_parent"
            android:max="10"
            android:paddingLeft="5dp"
            android:paddingRight="5dp"
            android:progress="1" >
        </SeekBar>
    </TableRow>

    <TableRow
        android:id="@+id/tableRow5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingTop="15dp" 
        android:layout_below="@id/tableRow4">

        <TextView
            android:id="@+id/TextView02"
            android:layout_width="wrap_content"
            android:paddingLeft="5dp"
            android:paddingRight="5dp"
            android:textColor="@color/Yellow1"
            android:text="@string/healthwarning" >
        </TextView>
    </TableRow>

    <TableRow
        android:id="@+id/tableRow6"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingTop="5dp"
        android:layout_below="@id/tableRow5" >

        <TextView
            android:id="@+id/TextViewHW2"
            android:layout_width="wrap_content"
            android:paddingLeft="5dp"
            android:paddingRight="5dp"
            android:textColor="@color/Orange1"
            android:text="@string/healthwarning2" >
        </TextView>
    </TableRow>

    <TableRow
        android:id="@+id/tableRow7"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingTop="5dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true" >

        <ToggleButton
            android:id="@+id/ToggleButton01"
            android:layout_width="wrap_content"
            android:background="@drawable/strobetoggle"
            android:paddingLeft="5dp"
            android:paddingRight="5dp" 
            android:text="">
        </ToggleButton>
    </TableRow>

</RelativeLayout>

现在问题是搜索栏无法正常工作。当我滑动任何搜索栏时，相机开始像一个垂死的灯泡一样闪烁。 我的Manifest文件中有相机权限。

另外，我还有另一个获得手电筒的课程。但是，当我从此活动转移到其他活动时，它会导致应用程序崩溃。

LauncherClass.java 

public class LightsOn extends Activity implements OnKeyListener {
    ImageView button;
    Boolean flashon = true;
    private boolean hasFlash;
    private boolean needOnPause = true;
    Parameters myparas;
    private Camera mycamera;
    int flash = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.lightson);

        hasFlash = getApplicationContext().getPackageManager()
                .hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);


        button = (ImageView) findViewById(R.id.power);
        button.setBackgroundResource(R.drawable.offswitch);
        button.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                if (flashon) {
                    Toast.makeText(LightsOn.this, "Flashlight off..!!",
                            Toast.LENGTH_SHORT).show();
                    button.setBackgroundResource(R.drawable.onswitch);
                    if (mycamera == null || myparas == null) {
                        return;
                    } else {
                        myparas = mycamera.getParameters();
                        myparas.setFlashMode(Parameters.FLASH_MODE_OFF);
                        mycamera.setParameters(myparas);
                        mycamera.stopPreview();
                        flashon = false;
                    }
                } else {
                    Toast.makeText(LightsOn.this, "Flashlight on..!!",
                            Toast.LENGTH_SHORT).show();
                    button.setBackgroundResource(R.drawable.offswitch);
                    if (mycamera == null || myparas == null) {
                        return;
                    } else {
                        myparas = mycamera.getParameters();
                        myparas.setFlashMode(Parameters.FLASH_MODE_TORCH);
                        mycamera.setParameters(myparas);
                        mycamera.startPreview();
                        flashon = true;
                    }
                }
            }
        });
    }

    private void getCamera() {
        if (mycamera == null) {
            try {
                mycamera = Camera.open();
                myparas = mycamera.getParameters();
            } catch (RuntimeException e) {
                Log.e("Camera Error. Failed to Open. Error: ", e.getMessage());
            }
        }

        if (!hasFlash) {
            AlertDialog.Builder dialog = new AlertDialog.Builder(this);
            dialog.setTitle("Sorry your device doesnt support flash.");
            dialog.setMessage("Press 'OKAY' to exit..");
            dialog.setPositiveButton("Okay.. :( :(",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            finish();
                            moveTaskToBack(true);
                        }
                    });
            dialog.setNegativeButton("More Apps by AKSHAT JAISWAL",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            Toast.makeText(LightsOn.this,
                                    "Account Coming Soon..", Toast.LENGTH_SHORT)
                                    .show();
                            finish();
                            moveTaskToBack(true);
                        }
                    });
            dialog.setNeutralButton("See website for more",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            Toast.makeText(LightsOn.this,
                                    "Website to be Launched Soon..",
                                    Toast.LENGTH_SHORT).show();
                            finish();
                            moveTaskToBack(true);
                        }
                    });

            dialog.show();
        }

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
    }

    @Override
    protected void onPause() {
        try {
            if (!needOnPause) {
                super.onPause();
            }

            else {
                super.onPause();
                Toast.makeText(LightsOn.this, "Flashlight off..!!",Toast.LENGTH_SHORT).show();
                button.setBackgroundResource(R.drawable.onswitch);
                myparas.setFlashMode(Parameters.FLASH_MODE_OFF);
                mycamera.setParameters(myparas);
                mycamera.stopPreview();
                flashon = false;
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    @Override
    protected void onRestart() {
        super.onRestart();
    }

    @Override
    protected void onResume() {
        super.onResume();
        Toast.makeText(LightsOn.this, "Flashlight on..!!", Toast.LENGTH_SHORT)
                .show();
        button.setBackgroundResource(R.drawable.offswitch);
        if (hasFlash)
            myparas = mycamera.getParameters();
        myparas.setFlashMode(Parameters.FLASH_MODE_TORCH);
        mycamera.setParameters(myparas);
        mycamera.startPreview();
        flashon = true;
    }

    @Override
    protected void onStop() {
        super.onStop();
    }

    @Override
    protected void onStart() {
        super.onStart();
        // on starting the app get the camera params
        getCamera();
    }


    @Override
    public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void onBackPressed() {
        // TODO Auto-generated method stub
        super.onBackPressed();

        myparas = mycamera.getParameters();
        myparas.setFlashMode(Parameters.FLASH_MODE_OFF);
        mycamera.setParameters(myparas);
        mycamera.stopPreview();
        flashon = false;

        if (mycamera != null) {
            mycamera.release();
            mycamera = null;
        }
        Log.d("Camera", "Back Pressed");
    }

}

2 个答案:

答案 0 :(得分：2)

您在AndroidManifest.xml使用了以下权限吗？

<uses-permission android:name="android.permission.CAMERA" /> 
<uses-permission android:name="android.permission.FLASHLIGHT" /> 
<uses-permission android:name="android.permission.WAKE_LOCK" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />    

<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-feature android:name="android.hardware.camera.flash" />

此外，您应该记得在使用后释放相机。

  

重要事项：调用release（）以释放相机以供其他应用程序使用。应用程序应立即在onPause（）中释放相机（并在onResume（）中重新打开（））。

如果你使用的是Android SDK 2.1，那么你应该注意火炬模式，这在三星设备上是不受支持的。有关详细信息，请参阅Here。

另请查看here和here

答案 1 :(得分：0)

在应用之间移动时，您的应用崩溃的原因是您的onPause。您没有释放相机，因此导致应用程序在退出活动时崩溃。在您的活动暂停时，只需松开相机即可。 

@Override
protected void onPause() {
    try {
        if (!needOnPause) {
            super.onPause();
        }

        else {
            super.onPause();
            Toast.makeText(LightsOn.this, "Flashlight off..!!",Toast.LENGTH_SHORT).show();
            button.setBackgroundResource(R.drawable.onswitch);
            myparas.setFlashMode(Parameters.FLASH_MODE_OFF);
            mycamera.setParameters(myparas);
            mycamera.stopPreview();
            flashon = false;
            mycamera.release();
        }
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
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