android - 从 Unity 访问 Android Camera.Parameters

Question

我想从 android 设备获取摄像头的数量，检查是否有一个是背面的，并为该摄像头获取水平和垂直视角 Camera.Parameters.getHorizontalViewAngle() .

我想通过 Unity3D c# 脚本执行此操作，但我的 Java 技能有限。有人可以提供帮助吗？我有这段代码:

using UnityEngine;

#if UNITY_ANDROID
public class CameraParametersAndroid
{
    public static float HorizontalViewAngle { get; protected set; }
    public static float VerticalViewAngle   { get; protected set; }
    public static int   numCameras          { get; protected set; }

    static CameraParametersAndroid()
    {
        AndroidJavaClass unityPlayerClass = new AndroidJavaClass ("com.unity3d.player.UnityPlayer"),
                         cameraClass = new AndroidJavaClass ("android.hardware.Camera"),
                         cameraParametersClass = new AndroidJavaClass ("android.hardware.Camera.Parameters"),
                         cameraInfoClass = new AndroidJavaClass ("android.hardware.Camera.CameraInfo");

        AndroidJavaObject currentActivity = unityPlayerClass.GetStatic<AndroidJavaObject>("currentActivity");
        object[] args = {currentActivity};

        AndroidJavaObject camera = cameraClass.CallStatic<AndroidJavaObject>("getCamera", args);

        if (camera != null)
        {
            AndroidJavaObject cameraParameters = camera.Call<AndroidJavaObject>("getParameters");

            numCameras = camera.Call<int>("getNumberOfCameras");
            HorizontalViewAngle = cameraParameters.Call<float>("getHorizontalViewAngle");
            VerticalViewAngle   = cameraParameters.Call<float>("getVerticalViewAngle");

        }
        else
        {
            Debug.LogError("[CameraParametersAndroid] Camera not available");
        }
    }
}
#endif

但即使是 getNumberOfCameras() 也不是通话有效。

Answer 1

getNumberOfCameras是一个静态方法，所以你需要 CallStatic你的 'cameraClass'

“android.hardware.Camera”中没有“getCamera”方法(或者至少我在文档中找不到它)。您应该改用“Camera.open”，但有一个技巧。 “Camera.open”要求您的应用具有相机权限，除非您使用内置相机功能，否则 Unity 不会生成这些权限。

以下适用于 Android ICS:

using UnityEngine;

#if UNITY_ANDROID
public class CameraParametersAndroid
{
    public static float HorizontalViewAngle { get; protected set; }
    public static float VerticalViewAngle { get; protected set; }
    public static int numCameras { get; protected set; }

    static CameraParametersAndroid()
    {
        AndroidJavaClass cameraClass = new AndroidJavaClass("android.hardware.Camera");

        numCameras = cameraClass.CallStatic<int>("getNumberOfCameras");

        // This is an ugly hack to make Unity
        // generate Camera permisions
        WebCamDevice[] devices = WebCamTexture.devices;

        // Camera.open gets back-facing camera by default
        // you should check for exceptions
        int camID = 0;
        AndroidJavaObject camera = cameraClass.CallStatic<AndroidJavaObject>("open", camID);

        // I'm pretty sure camera will never be null at this point
        // It will either be a valid object or Camera.open would throw an exception
        if (camera != null)
        {
            AndroidJavaObject cameraParameters = camera.Call<AndroidJavaObject>("getParameters");
            HorizontalViewAngle = cameraParameters.Call<float>("getHorizontalViewAngle");
            VerticalViewAngle = cameraParameters.Call<float>("getVerticalViewAngle");

        }
        else
        {
            Debug.LogError("[CameraParametersAndroid] Camera not available");
        }
    }
}
#endif