Cordova WP8 插件开发

　　前面博客中介绍了Cordova WP8平台上的安装部署，Cordova扩展可以利用WP8本地代码扩展WebApp的功能，调用本地能力需要开发相应的插件，下面以闪光灯作为实例来描述创建一个WP8插件的详细步骤，对于闪光灯实现打开和关闭两个接口函数。

　　

1.  创建插件类

　　创建闪光灯插件类FlashLight需继承BaseCommand，通常我们会在工程目录下创建Plugins目录用于存放插件类。即在Plugins目录下创建FlashLight.cs文件。

　　编写FlashLight.cs文件，添加如下代码：

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 using Windows.Phone.Media.Capture;
 7 using WPCordovaClassLib.Cordova;
 8 using WPCordovaClassLib.Cordova.Commands;
 9 
10 namespace TestCordova.Plugins
11 {
12     class FlashLight : BaseCommand
13     {
14         /// <summary>
15         /// 闪光灯实例
16         /// </summary>
17         protected static AudioVideoCaptureDevice Device { get; set; }
18 
19         /// <summary>
20         /// 打开闪光灯
21         /// </summary>
22         /// <returns></returns>
23         public async Task trunOn(string options)
24         {
25             var sensorLocation = CameraSensorLocation.Back;
26 
27             try
28             {
29                 if (Device == null)
30                 {
31                     //取得 AudioViceoCaptureDevice
32                     Device = await AudioVideoCaptureDevice.OpenAsync(sensorLocation, AudioVideoCaptureDevice.GetAvailableCaptureResolutions(sensorLocation).First());
33                 }
34 
35                 // 打开闪光灯
36                 var supportedCameraModes = AudioVideoCaptureDevice.GetSupportedPropertyValues(sensorLocation, KnownCameraAudioVideoProperties.VideoTorchMode);
37                 if (supportedCameraModes.ToList().Contains((UInt32)VideoTorchMode.On))
38                 {
39                     Device.SetProperty(KnownCameraAudioVideoProperties.VideoTorchMode, VideoTorchMode.On);
40 
41                     // 设定亮度为最大
42                     Device.SetProperty(KnownCameraAudioVideoProperties.VideoTorchPower, AudioVideoCaptureDevice.GetSupportedPropertyRange(sensorLocation, KnownCameraAudioVideoProperties.VideoTorchPower).Max);
43                 }
44 
45                 //返回状态
46                 DispatchCommandResult(new PluginResult(PluginResult.Status.OK, "{data: \"ok\"}"));
47             }
48             catch (Exception ex)
49             {
50                 // 无法控制闪光灯,返回错误状态
51                 DispatchCommandResult(new PluginResult(PluginResult.Status.JSON_EXCEPTION));
52             }
53         }
54 
55         /// <summary>
56         /// 关闭闪光灯
57         /// </summary>
58         public void trunOff(string options)
59         {
60             var sensorLocation = CameraSensorLocation.Back;
61 
62             try
63             {
64                 var supportedCameraModes = AudioVideoCaptureDevice
65                     .GetSupportedPropertyValues(sensorLocation, KnownCameraAudioVideoProperties.VideoTorchMode);
66                 // 关闭闪光灯
67                 if (Device != null && supportedCameraModes.ToList().Contains((UInt32)VideoTorchMode.Off))
68                 {
69                     Device.SetProperty(KnownCameraAudioVideoProperties.VideoTorchMode, VideoTorchMode.Off);
70                 }
71 
72                 //返回状态
73                 DispatchCommandResult(new PluginResult(PluginResult.Status.OK, "{data: \"ok\"}"));
74             }
75             catch (Exception ex)
76             {
77                 // 无法控制闪光灯,返回错误状态
78                 System.Diagnostics.Debug.WriteLine(ex);
79                 DispatchCommandResult(new PluginResult(PluginResult.Status.JSON_EXCEPTION));
80             }
81         }
82     }
83 }

FlashLight