ARFoundation入门教程U2-AR场景截图截屏

《ARFoundation入门教程U1-android权限申请和配置升级》配置了android权限申请，获取权限后使用代码截屏，AR场景与现实的合照便能以图片的形式保存到手机上，还可以分享给好友。

一、unity的文件保存路径

Unity的几个重要的路径：

• Resources（只读）

• StreamingAssets（只读）

• Application.dataPath（只读）

• Application.persistentDataPath（可读写）

1.重要路径之之Resources

• Resources文件夹下的资源无论使用与否都会被打包

• 资源会被压缩，转化成二进制

• 打包后文件夹下的资源只读

• 无法动态更改，无法做热更新

• 使用Resources.Load加载

2.重要路径之StreamingAssets

• 流数据的缓存目录

• 文件夹下的资源无论使用与否都会被打包

• 资源不会被压缩和加密

• 打包后文件夹下的资源只读，主要存放二进制文件

• 无法做热更新

• WWW类加载（一般用CreateFromFile ，若资源是AssetBundle，依据其打包方式看是否是压缩的来决定）

• 相对路径，具体路径依赖于实际平台

•Application.streamingAssetsPath

3.重要路径之Application.dataPath

• 游戏的数据文件夹的路径（例如在Editor中的Assets）

• 很少用到

• 无法做热更新

4.重要路径之Application.persistentDataPath

• 持久化数据存储目录的路径（沙盒目录，打包之前不存在）

• 文件夹下的资源无论使用与否都会被打包

• 运行时有效，可读写

• 无内容限制，从StreamingAsset中读取二进制文件或从AssetBundle读取文件来写入PersistentDataPath中

• 适合热更新

5.各平台目录路径[1]

IOS:
Application.dataPath:Application/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/xxx.app/Data

Application.streamingAssetsPath:Application/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/xxx.app/Data/Raw

Application.persistentDataPath:Application/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/Documents

Application.temporaryCachePath:Application/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/Library/Caches

android:
Application.dataPath: /data/app/xxx.xxx.xxx.apk

Application.streamingAssetsPath:jar:file:///data/app/xxx.xxx.xxx.apk/!/assets

Application.persistentDataPath:/data/data/xxx.xxx.xxx/files

Application.temporaryCachePath:/data/data/xxx.xxx.xxx/cache

Windows Web Player:
Application.dataPath:file:///D:/MyGame/WebPlayer (即导包后保存的文件夹，html文件所在文件夹)

Application.streamingAssetsPath :

Application.persistentDataPath :

Application.temporaryCachePath :

注意：
1.Application.persistentDataPath才是移动端可用的保存生成文件的地方

2.放到resource中打包后不可以更改了

3.放到Application .dataPath中移动端是没有访问权限的

二、unity的截图方法

1.UnityEngine自带api，全屏截图：

UnityEngine.ScreenCapture.CaptureScreenshot(fileName);//截图并保存截图文件

或

Texture2D tex = UnityEngine.ScreenCapture.CaptureScreenshotAsTexture();//截图返回

2.使用Texture2D截取屏幕内像素

Texture2D tex = new Texture2D((int)rect.width, (int)rect.height, TextureFormat.ARGB32, false);//新建一个Texture2D对象

3.根据相机截图

camera.targetTexture = render;//设置截图相机的targetTexture为render

camera.Render();//手动开启截图相机的渲染

RenderTexture.active = render;//激活RenderTexture

Texture2D tex = new Texture2D((int)rect.width, (int)rect.height, TextureFormat.ARGB32, false);//新建一个Texture2D对象

tex.ReadPixels(rect, 0, 0);//读取像素

tex.Apply();//保存像素信息

三、编写脚本代码

新建CaptureScreenshotMgr.cs脚本，编写截图代码，挂载到ARView对象上：

代码：

using UnityEngine;

using System.Collections;

using System;

using System.IO;

using UnityEngine.UI;



namespace FrameworkDesign.Example

{



    /// <summary>

    /// 截图保存安卓手机相册

    /// </summary>

    public class CaptureScreenshotMgr : MonoBehaviour

    {

        public bool isUi = false;//控制截图内容是否带UI      

        string path = Application.persistentDataPath.Substring(0, Application.persistentDataPath.IndexOf("Android")) + "baidu/";

        private void Update()

        {

        }

        /// <summary>

        /// 保存截屏图片，并且刷新相册 Android

        /// </summary>

        /// <param name="name">若空就按照时间命名</param>

        public void CaptureScreenshot(string fileName)

        {

                  

            string name = fileName + GetCurTime() + ".jpg";



#if UNITY_STANDALONE_WIN      //PC平台

       // 编辑器下

       // string path = Application.persistentDataPath + "/" + _name;      

        string path = Application.dataPath + "/" + _name;

        ScreenCapture.CaptureScreenshot(path, 0);

        Debug.Log("图片保存地址" + path);



#elif UNITY_ANDROID     //安卓平台

            //Android版本

            if (isUi)

            {

                StartCoroutine(CutImage1(name));

            }

            else

            {

                StartCoroutine(CutImage(name));

            }

#endif

        }

        //截屏并保存///不带UI；根据相机截图

        IEnumerator CutImage(string name)

        {

            RenderTexture rt = new RenderTexture(Screen.width, Screen.height, 0);//创建一个RenderTexture对象

            yield return new WaitForEndOfFrame();

            Camera.main.targetTexture = rt;//设置截图相机的targetTexture为render

            Camera.main.Render();//手动开启截图相机的渲染

            RenderTexture.active = rt;//激活RenderTexture



            Texture2D tex = new Texture2D(Screen.width, Screen.height, TextureFormat.RGB24, true);// 新建一个Texture2D对象



            tex.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0, true);//读像素

            tex.Apply();//保存像素信息



            Camera.main.targetTexture = null;//重置截图相机的targetTexture

            RenderTexture.active = null;//关闭RenderTexture的激活状态

            Destroy(rt);//删除RenderTexture对象



            yield return tex;

            byte[] byt = tex.EncodeToPNG();

          

            SavePic(name, byt);

        }

        private void SavePic(string name, byte[] byt)

        {

            //string path = Application.persistentDataPath.Substring(0, Application.persistentDataPath.IndexOf("Android")) + "baidu/";

            string pathName = path + name;

            Logger.Log("SavePic:" + pathName);

            try

            {

                //安卓平台抛出UnauthorizedAccessException错误

                CreateFileInPersistentData(pathName);

                File.WriteAllBytes(pathName, byt);

               // Logger.Log("WriteAllBytes:" + pathName);

            }

            catch (Exception e)

            {

                Logger.Log("CreateFileInPersistentData-Exception:" + e.ToString());

            }

            AndroidJavaClass jc = new AndroidJavaClass("com.unity3d.player.MainActivity");

            AndroidJavaObject jo = jc.CallStatic<AndroidJavaObject>("GetInstance");//MainActivity实例

            string[] paths = new string[1];

            paths[0] = path;

            ScanFile(paths);

        }

        public void CreateFileInPersistentData(string pathName)

        {

            string path = pathName;

            if (File.Exists(path))

            {

                return;//存在该文件

            }

            else

            {

                //文件不存在

                FileStream fs = new FileStream(path, FileMode.Create);

                fs.Close();

            }

        }

        //截图并保存带UI；使用Texture2D截取屏幕内像素

        IEnumerator CutImage1(string name)

        {

            yield return new WaitForEndOfFrame();//等到帧结束

            //图片大小 

            Texture2D tex = new Texture2D(Screen.width, Screen.height, TextureFormat.RGB24, true);// 新建一个Texture2D对象

            yield return new WaitForEndOfFrame();



            tex.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0, true);//读像素

            tex.Apply();//保存像素信息



            yield return tex;

            byte[] byt = tex.EncodeToPNG();

         

            SavePic(name, byt);

        }

        //刷新图片，显示到相册中

        void ScanFile(string[] path)

        {

            //Logger.Log("ScanFile:" + path[0]);

            using (AndroidJavaClass PlayerActivity = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))

            {

                AndroidJavaObject playerActivity = PlayerActivity.GetStatic<AndroidJavaObject>("currentActivity");//当前Activity-MainActivity

                using (AndroidJavaObject Conn = new AndroidJavaObject("android.media.MediaScannerConnection", playerActivity, null))

                {

                    //Logger.Log("ScanFile:CallStatic" );

                    Conn.CallStatic("scanFile", playerActivity, path, null, null);//调用MediaScannerConnection的scanFile

                }

            }



        }

        /// <summary>

        /// 获取当前年月日时分秒，如20181001444

        /// </summary>

        /// <returns></returns>

        string GetCurTime()

        {

            return DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString()

                + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString();

        }







    }



}

三、android打包运行

如未配置，参看《ARFoundation从零开始3-arfoundation项目》。

安装运行，截图保存在手机sd卡。

四、常见问题

五、参考资料

[1]：https://blog.csdn.net/c651088720/article/details/94621145