Android 连接到摄影机时出错：0

我刚刚开始学习android编程，并尝试编写一个手电筒应用程序，eclipse中没有错误，只是在我的setButton行上有一个关于不推荐代码的警告

每当我尝试运行应用程序时，LogCat都会说连接到摄像头时出错：0

我添加了摄像头的权限，并且没有运行需要摄像头的应用程序，所以我不知道发生了什么，我的代码中是否存在我没有看到的问题

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ImageButton;

public class MainActivity extends Activity {

    ImageButton btnSwitch;

    private Camera camera;
    private boolean isFlashOn;
    private boolean hasFlash;
    Parameters params;
    MediaPlayer mp;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // flash switch button
        btnSwitch = (ImageButton) findViewById(R.id.btnSwitch);

        /*
         * First check if device is supporting flashlight or not
         */
        hasFlash = getApplicationContext().getPackageManager()
                .hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);

        if (!hasFlash) {
            // device doesn't support flash
            // Show alert message and close the application
            AlertDialog alert = new AlertDialog.Builder(MainActivity.this)
                .create();
        alert.setTitle("Error");
        alert.setMessage("Sorry, your device doesn't support flash light!");
        alert.setButton("OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                // closing the application
                finish();
            }
        });
        alert.show();
        return;
    }

    // get the camera
    getCamera();

    // displaying button image
    toggleButtonImage();

    /*
     * Switch button click event to toggle flash on/off
     */
    btnSwitch.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            if (isFlashOn) {
                // turn off flash
                turnOffFlash();
            } else {
                // turn on flash
                turnOnFlash();
            }
        }
    });
}

/*
 * Get the camera
 */
private void getCamera() {
    if (camera == null) {
        try {
            camera = Camera.open();
            params = camera.getParameters();
        } catch (RuntimeException e) {
            Log.e("Camera Error. Failed to Open. Error: ", e.getMessage());
        }
    }
}

/*
 * Turning On flash
 */
private void turnOnFlash() {
    if (!isFlashOn) {
        if (camera == null || params == null) {
            return;
        }
        // play sound
        playSound();

        params = camera.getParameters();
        params.setFlashMode(Parameters.FLASH_MODE_TORCH);
        camera.setParameters(params);
        camera.startPreview();
        isFlashOn = true;

        // changing button/switch image
        toggleButtonImage();
    }

}

/*
 * Turning Off flash
 */
private void turnOffFlash() {
    if (isFlashOn) {
        if (camera == null || params == null) {
            return;
        }
        // play sound
        playSound();

        params = camera.getParameters();
        params.setFlashMode(Parameters.FLASH_MODE_OFF);
        camera.setParameters(params);
        camera.stopPreview();
        isFlashOn = false;

        // changing button/switch image
        toggleButtonImage();
    }
}

/*
 * Playing sound
 * will play button toggle sound on flash on / off
 * */
private void playSound(){
    if(isFlashOn){
        mp = MediaPlayer.create(MainActivity.this, R.raw.light_switch_off);
    }else{
        mp = MediaPlayer.create(MainActivity.this, R.raw.light_switch_on);
    }
    mp.setOnCompletionListener(new OnCompletionListener() {

        @Override
        public void onCompletion(MediaPlayer mp) {
            // TODO Auto-generated method stub
            mp.release();
        }
    }); 
    mp.start();
}

/*
 * Toggle switch button images
 * changing image states to on / off
 * */
private void toggleButtonImage(){
    if(isFlashOn){
        btnSwitch.setImageResource(R.drawable.btn_switch_on);
    }else{
        btnSwitch.setImageResource(R.drawable.btn_switch_off);
    }
}

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

@Override
protected void onPause() {
    super.onPause();

    // on pause turn off the flash
    turnOffFlash();
}

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

    @Override
    protected void onResume() {
        super.onResume();

        // on resume turn on the flash
        if(hasFlash)
            turnOnFlash();
    }

    @Override
    protected void onStart() {
        super.onStart();

        // on starting the app get the camera params
        getCamera();
    }

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

        // on stop release the camera
        if (camera != null) {
            camera.release();
        camera = null;
        }
    }

}

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有一个我不知道的权限问题

：编辑：

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我使用的环境没有设置我使用gui中的菜单添加的权限，它没有添加我想要的相机权限，我必须手动添加它们，这样当它们不在时我就认为它们在那里了

尝试调用camera.open0；取而代之，看看会发生什么。对此有任何解决方案，请用您的答案更新，以使其有帮助。解决您的问题不会让其他人解决他们的问题。如果你有自己的问题的解决办法，就一定要回答。