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android 實現手電筒功能

1.AndroidManifest.xml 中新增許可權

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

2.程式控制

 // 獲得Camera物件,通過Camera.open()開啟攝像頭。
Camera   camera = Camera.open();
//開啟閃光燈
public static void turnLightOn(Camera mCamera) {
  if (mCamera == null) {
   return;
  }
  Parameters parameters = mCamera.getParameters();
  if (parameters == null) {
   return;
  }
    List<String> flashModes = parameters.getSupportedFlashModes();
    // Check if camera flash exists
    if (flashModes == null) {
       // Use the screen as a flashlight (next best thing)
       return;
    }
    String flashMode = parameters.getFlashMode();
    if (!Parameters.FLASH_MODE_TORCH.equals(flashMode)) {
       // Turn on the flash
       if (flashModes.contains(Parameters.FLASH_MODE_TORCH)) {
           parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
           mCamera.setParameters(parameters);
        } else {
        }
    }
}
//關閉閃光燈
public static void turnLightOff(Camera mCamera) {
  if (mCamera == null) {
    return;
  }
  Parameters parameters = mCamera.getParameters();
  if (parameters == null) {
    return;
  }
  List<String> flashModes = parameters.getSupportedFlashModes();
  String flashMode = parameters.getFlashMode();
  // Check if camera flash exists
  if (flashModes == null) {
    return;
  }
  if (!Parameters.FLASH_MODE_OFF.equals(flashMode)) {
  // Turn off the flash
   if (flashModes.contains(Parameters.FLASH_MODE_OFF)) {
     parameters.setFlashMode(Parameters.FLASH_MODE_OFF);
     mCamera.setParameters(parameters);
   } else {
         Log.e(TAG, "FLASH_MODE_OFF not supported");
      }
    }
}

//退出閃光燈釋放Camear物件
camera.release();