Android 通用型手电筒代码

前几天这边一个小区断电，黑麻麻的，一只猫闯进寝室，把我吓哭，然后就果断写了个手电筒，下次断电，再来，我要吓死它。

我之前看到很多人都是直接调用闪光灯，其实大部分机型都不支持，我这个是用相机功能来实现的，大部分机型都支持。

MainActivity.class

public class MainActivity extends FragmentActivity {

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

    if (isFlashSupported()) {
      if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction().add(R.id.container, new FlashlightFragment()).commit();
      }
    } else {
      showNoFlashAlert();
    }
  }

  private void showNoFlashAlert() {
    new AlertDialog.Builder(this)
        .setMessage(R.string.device_not_support_msg)
        .setIcon(android.R.drawable.ic_dialog_alert).setTitle(R.string.device_not_support_title)
        .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {

          @Override
          public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
            finish();
          }
        }).create().show();
  }

  private boolean isFlashSupported() {
    PackageManager pm = getPackageManager();
    return pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
  }

  public static class FlashlightFragment extends Fragment implements SurfaceHolder.Callback {

    public FlashlightFragment() { }

    ImageButton btnSwitch;
    ImageView bg;
    private boolean isLighOn = false;

    private Camera camera;
    Camera.Parameters params;

    @Override
    public void onStart() {
      super.onStart();
      SurfaceView preview = (SurfaceView) getView().findViewById(R.id.PREVIEW);
      SurfaceHolder mHolder = preview.getHolder();
      mHolder.addCallback(this);
    }

    @Override
    public void onPause() {
      super.onPause();
      turnOffFlash();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      View view = inflater.inflate(R.layout.fragment_main_activity, container, false);

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

      bg = (ImageView) view.findViewById(R.id.flashlight_bg);

      // displaying button image
      toggleBgImage();

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

        @Override
        public void onClick(View v) {
          if (isLighOn) {
            turnOffFlash();
          } else {
            turnOnFlash();
          }
        }
      });

      return view;
    }

    // Turning On flash
    private void turnOnFlash() {

      if (!isLighOn) {
        if (camera == null || params == null) {
          return;
        }
        params = camera.getParameters();
        params.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
        camera.setParameters(params);
        camera.startPreview();
        isLighOn = true;

        toggleBgImage();
      }

    }

    // Turning Off flash
    private void turnOffFlash() {

      if (isLighOn) {
        if (camera == null || params == null) {
          return;
        }

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

        toggleBgImage();
      }
    }

    private void toggleBgImage() {
      if (isLighOn) {
        bg.setImageResource(R.mipmap.f_on);
      } else {
        bg.setImageResource(R.mipmap.f_off);
      }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
      if (camera != null) {
        camera.stopPreview();
        camera.setPreviewCallback(null);
        camera.release();
        camera = null;
      }
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
      if (camera == null) {
        camera = Camera.open();
        params = camera.getParameters();
        try {
          camera.setPreviewDisplay(holder);
        } catch (IOException e) {
          camera.release();
          camera = null;
        }
      }

      turnOnFlash();
    }

  }

}

fragment_main_activity.xml

<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  >

  <SurfaceView
    android:id="@+id/PREVIEW"
    android:layout_width="1dp"
    android:layout_height="1dp"/>

  <ImageView
    android:id="@+id/flashlight_bg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:src="@mipmap/f_on"
    android:scaleType="centerCrop"
    />

  <ImageButton
    android:id="@+id/flashlight_button"
    android:layout_width="100dp"
    android:layout_height="200dp"
    android:layout_centerInParent="true"
    android:background="@android:color/transparent"
    android:text="fuck"/>

</RelativeLayout>

activity_main.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:id="@+id/container"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       />

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.liujinghuiuncleapp.app.tool.flashlight" >

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

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

  <application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:theme="@style/AppTheme"
    android:label="@string/app_name" >
    <activity
      android:name=".MainActivity"
      android:label="@string/app_name" >
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
  </application>

</manifest>

以上所述就是本文的全部内容了，希望大家能够喜欢。