参考：uni-app 手电打开和关闭_逆境中徘徊的博客-CSDN博客_uniapp打开闪光灯

可直接查看原文章

js文件    flashlight.js

 
// 打开闪光灯
export const  onTorch=()=>{
	try{
		var os = plus.os.name;
		if('iOS' == os){
			var device = plus.ios.invoke('AVCaptureDevice', 'defaultDeviceWithMediaType:', 'vide');
			plus.ios.invoke(device, 'lockForConfiguration:', null);
			plus.ios.invoke(device, 'setTorchMode:', 1);
			plus.ios.invoke(device, 'setFlashMode:', 1);
			plus.ios.invoke(device, 'unlockForConfiguration');
		}else{
			var main = plus.android.runtimeMainActivity();
			var camera = main.getSystemService('camera');
			var ids = plus.android.invoke(camera, 'getCameraIdList');
			for (var i = 0; i < ids.length; i++) {
				var c = plus.android.invoke(camera, 'getCameraCharacteristics', ids[i]);
				var available = plus.android.invoke(c, 'get', plus.android.getAttribute(c, 'FLASH_INFO_AVAILABLE'));
				var facing = plus.android.invoke(c, 'get', plus.android.getAttribute(c, 'LENS_FACING'));
				if(null!=available&&available&&null!=facing&&1==facing){
					plus.android.invoke(camera, 'setTorchMode', ids[i], true);
				}
			}
		}
	}catch(e){
		console.error('error @onTorch!!');
	}
}
 

//关闭闪光灯
export const offTorch=()=>{
	try{
		var os = plus.os.name;
		if('iOS' == os){
			var device = plus.ios.invoke('AVCaptureDevice', 'defaultDeviceWithMediaType:', 'vide');
			plus.ios.invoke(device, 'lockForConfiguration:', null);
			plus.ios.invoke(device, 'setTorchMode:', 0);
			plus.ios.invoke(device, 'setFlashMode:', 0);
			plus.ios.invoke(device, 'unlockForConfiguration');
		}else{
			var main = plus.android.runtimeMainActivity();
			var camera = main.getSystemService('camera');
			var ids = plus.android.invoke(camera, 'getCameraIdList');
			for (var i = 0; i < ids.length; i++) {
				var c = plus.android.invoke(camera, 'getCameraCharacteristics', ids[i]);
				var available = plus.android.invoke(c, 'get', plus.android.getAttribute(c, 'FLASH_INFO_AVAILABLE'));
				var facing = plus.android.invoke(c, 'get', plus.android.getAttribute(c, 'LENS_FACING'));
				if(null!=available&&available&&null!=facing&&1==facing){
					plus.android.invoke(camera, 'setTorchMode', ids[i], false);
				}
			}
		}
	}catch(e){
		console.error('error @offTorch!!');
	}
}

引用 

<script>
import {offTorch,onTorch} from "./flashlight.js"

函数内使用(){
    if(true){
	    console.log('打开手电筒');
	    onTorch();
    }else{
	    console.log('关闭手电筒');
	    offTorch()
    }
}
</script>