在AndroidManifest中注册相应的权限：
<uses-permission android:name="android.permission.FLASHLIGHT" />
<uses-permission android:name="android.permission.CAMERA"/>
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.autofocus"/>
打开闪光灯关键代码：
Camera camera = Camera.open();
camera.startPreview();
parameter = camera.getParameters();
parameter.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(parameter);
关闭闪关灯关键代码：
parameter = camera.getParameters();
parameter.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(parameter);
public class FlashlightManager {
private static final String TAG = FlashlightManager.class.getSimpleName();
private static final Object iHardwareService;
private static final Method setFlashEnabledMethod;
static {
iHardwareService = getHardwareService();
setFlashEnabledMethod = getSetFlashEnabledMethod(iHardwareService);
if (iHardwareService == null) {
Log.v(TAG, "This device does supports control of a flashlight");
} else {
Log.v(TAG, "This device does not support control of a flashlight");
}
}
private FlashlightManager() {
}
private static Object getHardwareService() {
Class<?> serviceManagerClass = maybeForName("android.os.ServiceManager");
if (serviceManagerClass == null) {
return null;
}
Method getServiceMethod = maybeGetMethod(serviceManagerClass,
"getService", String.class);
if (getServiceMethod == null) {
return null;
}
Object hardwareService = invoke(getServiceMethod, null, "hardware");
if (hardwareService == null) {
return null;
}
Class<?> iHardwareServiceStubClass = maybeForName("android.os.IHardwareService$Stub");
if (iHardwareServiceStubClass == null) {
return null;
}
Method asInterfaceMethod = maybeGetMethod(iHardwareServiceStubClass,
"asInterface", IBinder.class);
if (asInterfaceMethod == null) {
return null;
}
return invoke(asInterfaceMethod, null, hardwareService);
}
private static Method getSetFlashEnabledMethod(Object iHardwareService) {
if (iHardwareService == null) {
return null;
}
Class<?> proxyClass = iHardwareService.getClass();
return maybeGetMethod(proxyClass, "setFlashlightEnabled", boolean.class);
}
private static Class<?> maybeForName(String name) {
try {
return Class.forName(name);
} catch (ClassNotFoundException cnfe) {
// OK
return null;
} catch (Exception re) {
re.printStackTrace();
Log.w(TAG, "Unexpected error while finding class " + name, re);
return null;
}
}
/**
* 通过设置Camera打开闪光灯
* @param mCamera
*/
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();
Log.i(TAG, "Flash mode: " + flashMode);
Log.i(TAG, "Flash modes: " + flashModes);
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 {
}
}
}
/**
* 通过设置Camera关闭闪光灯
* @param mCamera
*/
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;
}
Log.i(TAG, "Flash mode: " + flashMode);
Log.i(TAG, "Flash modes: " + flashModes);
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");
}
}
}
private static Method maybeGetMethod(Class<?> clazz, String name,
Class<?>... argClasses) {
try {
return clazz.getMethod(name, argClasses);
} catch (Exception nsme) {
nsme.printStackTrace();
// OK
return null;
}
}
private static Object invoke(Method method, Object instance, Object... args) {
try {
return method.invoke(instance, args);
} catch (Exception e) {
Log.w(TAG, "Unexpected error while invoking " + method, e);
return null;
}
}
/**
* 通过反射来操作闪光灯
* @param active
*/
public static void switchFlashlight(boolean active) {
setFlashlight(active);
}
static void disableFlashlight() {
setFlashlight(false);
}
private static void setFlashlight(boolean active) {
if (iHardwareService != null) {
invoke(setFlashEnabledMethod, iHardwareService, active);
}
}
}