Unity——Js和Unity互相调用

Unity项目可以打包成WebGl，打包后的项目文件：

Build中是打包后的Js代码；

Index.html是web项目的入口，里面可以调整web的自适应，也可以拿去嵌套；

TemplateData是打包时候选的webGl模板；

web端游戏可能Unity只负责做游戏部分，而官网由另外的团队制作，之间就需要Unity和Js代码之间的相互调用；

Unity调用JavaScript代码

声明一下，这里说的都是Unity和外部JS代码的互相调用，项目内调用有其他方法；

老版本提供一个过时的方法：

1.在WebGL项目中的Index.html中添加要调用的JS方法

function Unity2JavaScript() { alert("UnityToWeb") }

2.Unity中调用

Application.ExternalCall("Unity2JavaScript");

//可以有参数，没有返回值

//Application.ExternalCall("Unity2JavaScript",a,10,"aaaa");

Unity建议使用的方法：

1.在Plugins文件夹中，创建后缀为.jslib的文件，在其中写需要调用的js代码

mergeInto(LibraryManager.library, {

  Hello: function () {

    window.alert("Hello, world!");

  },

  HelloString: function (str) {

    window.alert(Pointer_stringify(str));

  },

  PrintFloatArray: function (array, size) {

    for(var i = 0; i < size; i++)

    console.log(HEAPF32[(array >> 2) + size]);

  },

  AddNumbers: function (x, y) {

    return x + y;

  },

  StringReturnValueFunction: function () {

    var returnStr = "bla";

    var buffer = _malloc(lengthBytesUTF8(returnStr) + 1);

    writeStringToMemory(returnStr, buffer);

    return buffer;

  },

  BindWebGLTexture: function (texture) {

    GLctx.bindTexture(GLctx.TEXTURE_2D, GL.textures[texture]);

  },

});

2.Unity中调用——__Internal.jslib

using UnityEngine;

using System.Runtime.InteropServices;

public class NewBehaviourScript : MonoBehaviour {

    [DllImport("__Internal")]

    private static extern void Hello();

    [DllImport("__Internal")]

    private static extern void HelloString(string str);

    [DllImport("__Internal")]

    private static extern void PrintFloatArray(float[] array, int size);

    [DllImport("__Internal")]

    private static extern int AddNumbers(int x, int y);

    [DllImport("__Internal")]

    private static extern string StringReturnValueFunction();

    [DllImport("__Internal")]

    private static extern void BindWebGLTexture(int texture);

    void Start() {

        Hello();

        HelloString("This is a string.");

        float[] myArray = new float[10];

        PrintFloatArray(myArray, myArray.Length);

        int result = AddNumbers(5, 7);

        Debug.Log(result);

        Debug.Log(StringReturnValueFunction());

        var texture = new Texture2D(0, 0, TextureFormat.ARGB32, false);

        BindWebGLTexture(texture.GetNativeTextureID());

    }

}

JavaScript调用Unity

这里面有巨坑，天坑，人都坑傻了！！！

官方文档中有这几行字

恰好我用的2020版本的Unity；

主要使用这个API——

SendMessage("游戏对象名","方法名","参数"); 这个和参数和lua调用c#差不多了，但是怎么调用这个api就很玄学了；

首先如果你调用这个方法需要在Unity的资源已经加载完成才可以，这个好解决，js加个button；

<button Type="button" onclick="TestSend()">WebToUnity</button>

其次在调用这个方法前需要先实例化UnityInstance变量；

var gameInstance = null;

script.onload = () => {

		gameInstance = createUnityInstance(document.querySelector("#unity-canvas"), {

        	dataUrl: "Build/Test.data",

        	frameworkUrl: "Build/Test.framework.js",

        	codeUrl: "Build/Test.wasm",

        	streamingAssetsUrl: "StreamingAssets",

        	companyName: "DefaultCompany",

       		productName: "UnityToWeb",

        	productVersion: "0.1",

      });

};

//以上的参数都可以在unity的playersetting界面找到；

最后调用时要在then中用lamda表达式

function TestSend() {

	gameInstance.then((unityInstance) => {

		unityInstance.SendMessage("Canvas","OnLogin","dqwreqweraf");

	});

}

完整的index.html

<!DOCTYPE html>

<html lang="en-us">

  <head>

    <meta charset="utf-8">

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">

    <title>Unity WebGL Player | UnityToWeb</title>

    <link rel="shortcut icon" href="TemplateData/favicon.ico">

    <link rel="stylesheet" href="TemplateData/style.css">

  </head>

  <body>

    <div id="unity-container" class="unity-desktop">

	<button Type="button" onclick="TestSend()">WebToUnity</button>

      <canvas id="unity-canvas" width=960 height=600></canvas>

      <div id="unity-loading-bar">

        <div id="unity-logo"></div>

        <div id="unity-progress-bar-empty">

          <div id="unity-progress-bar-full"></div>

        </div>

      </div>

      <div id="unity-mobile-warning">

        WebGL builds are not supported on mobile devices.

      </div>

      <div id="unity-footer">

        <div id="unity-webgl-logo"></div>

        <div id="unity-fullscreen-button"></div>

        <div id="unity-build-title">UnityToWeb</div>

      </div>

    </div>

    <script>

      var buildUrl = "Build";

      var loaderUrl = buildUrl + "/Test.loader.js";

      var config = {

        dataUrl: buildUrl + "/Test.data",

        frameworkUrl: buildUrl + "/Test.framework.js",

        codeUrl: buildUrl + "/Test.wasm",

        streamingAssetsUrl: "StreamingAssets",

        companyName: "DefaultCompany",

        productName: "UnityToWeb",

        productVersion: "0.1",

      };

      var container = document.querySelector("#unity-container");

      var canvas = document.querySelector("#unity-canvas");

      var loadingBar = document.querySelector("#unity-loading-bar");

      var progressBarFull = document.querySelector("#unity-progress-bar-full");

      var fullscreenButton = document.querySelector("#unity-fullscreen-button");

      var mobileWarning = document.querySelector("#unity-mobile-warning");

      // By default Unity keeps WebGL canvas render target size matched with

      // the DOM size of the canvas element (scaled by window.devicePixelRatio)

      // Set this to false if you want to decouple this synchronization from

      // happening inside the engine, and you would instead like to size up

      // the canvas DOM size and WebGL render target sizes yourself.

      // config.matchWebGLToCanvasSize = false;

      if (/iPhone|iPad|iPod|Android/i.test(navigator.userAgent)) {

        container.className = "unity-mobile";

        // Avoid draining fillrate performance on mobile devices,

        // and default/override low DPI mode on mobile browsers.

        config.devicePixelRatio = 1;

        mobileWarning.style.display = "block";

        setTimeout(() => {

          mobileWarning.style.display = "none";

        }, 5000);

      } else {

        canvas.style.width = "960px";

        canvas.style.height = "600px";

      }

      loadingBar.style.display = "block";

      var script = document.createElement("script");

      script.src = loaderUrl;

	  var gameInstance = null;

      script.onload = () => {

		gameInstance = createUnityInstance(document.querySelector("#unity-canvas"), {

         dataUrl: "Build/Test.data",

        frameworkUrl: "Build/Test.framework.js",

        codeUrl: "Build/Test.wasm",

        streamingAssetsUrl: "StreamingAssets",

        companyName: "DefaultCompany",

        productName: "UnityToWeb",

        productVersion: "0.1",

      });

      };

	  function TestSend() {

            gameInstance.then((unityInstance) => {

            unityInstance.SendMessage("Canvas","OnLogin","dqwreqweraf");

            });

          }

      document.body.appendChild(script);

    </script>

  </body>

</html>