问题
Following is the code which I used for opening Torch and closing it. But when I close it, it crashes. LogCat says " Runtime Exception : Fail to connect to camera service "!
+ hasFlash is not getting any value and is throwing Nullpointer exception. (I'm using it to check if the flash is present or not.)
What am I doing Wrong?
boolean hasFlash = this.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
if(hasFlash==true)
{
if(s.equalsIgnoreCase("FlashLight On") || s.equalsIgnoreCase("Flash Light On"))
{
Camera cam = Camera.open();
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
cam.setParameters(p);
return "Turning on";
}
if(s.equalsIgnoreCase("FlashLight Off") || s.equalsIgnoreCase("Flash Light Off"))
{
Camera cam = Camera.open();
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_OFF);
cam.setParameters(p);
cam.stopPreview();
cam.release();
return "Turning off";
}
}
else
{
return "Flash Not Available";
}
回答1:
Change
Camera cam = Camera.open();
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_OFF);
cam.setParameters(p);
cam.stopPreview();
cam.release();
return "Turning off";
to
cam.stopPreview();
cam.release();
return "Turning off";
I ran into a lot of these issues building an open source flashlight for Android which may help you with further questions.
Flashlight by Joe github
来源：https://stackoverflow.com/questions/23401891/flashlight-torch-is-opening-but-not-closing