Android如何打开闪光灯

2024-06-07 14:42| 来源: 网络整理| 查看: 265

Android如何打开闪光灯转载

peihp 2021-07-12 16:30:42

文章标签安卓闪光灯文章分类 Android 移动开发

在android中打开闪光灯的方法有两种，一种是获取硬件服务，通过反射的方式来操作闪光灯。另外一种是获得Camera对象，通过设置Camera的参数来操作闪光灯。一下是一个操作闪光灯的工具类：实现了两种方式操作闪光灯。通过switchFlashlight方法是通过反射的方式操作，通过turnLightOn，turnLightOff方法操作是通过设置Camera来操作闪关灯的。通过反射的方法貌似在4.0以上的版本中都不好用了，建议使用设置摄像头参数的方式来操作。

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 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 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); } } }

赞收藏评论分享举报

上一篇：Android StudioV3.2.1以上版本的两种模式及签名配置、apk打包混淆

下一篇：寒冬已至？四面楚歌的Android工程师该何去何从

【本文地址】

公司简介

联系我们

今日新闻

推荐新闻

专题文章