开发环境：
Android studio 3.5.2
Unity3d 2020.3.25f1c1
目录
5，导入Unity3d的 UnityPlayerActivity.java
Android Studio部分
1，创建New Project
创建New Project ,Empty Activity ,package com.example.unity2photo
2，创建新的 Module ，命名test
切换到Project ,New – Module ,Android Library 点Next 。
3，删掉默认创建的多余的 Moudle app
Open Module Settings 选择APP 点 – 号， Yes ,再Delete。
4，导入Unity3d的 classes.jar
Unity3d 安装路径下面对应的位置：
D:\Software\Unity\2020.3.25f1c1\Editor\Data\PlaybackEngines\AndroidPlayer\Variations\mono\Development\Classes
复制class.jar 粘贴到libs目录下面，右键classer.jar - Add As Library
5，导入Unity3d的 UnityPlayerActivity.java
D:\Software\Unity\2020.3.25f1c1\Editor\Data\PlaybackEngines\AndroidPlayer\Source\com\unity3d\player
复制UnityPlayerActivity.java 粘贴到 src – main- java - com.example.test 下面
6，创建MainActivity
右键com.example.test ，New –Activity – Empty Activity
7，Java代码部分
package com.example.test;
import android.Manifest;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.os.Bundle;
import com.unity3d.player.UnityPlayer;
import com.unity3d.player.unity_player.UnityPlayerActivity;
public class MainActivity extends UnityPlayerActivity{
// @Override
// protected void onCreate(Bundle savedInstanceState) {
// super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_main);
// }
// @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// 获取存储权限,不然的话无法获取图片
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE}, 100);
}
}
// unity点击按钮触发这个方法
public void startPhoto() {
Log.d("unity","打开相册");
Intent intent = new Intent(Intent.ACTION_PICK);
intent.setType("image/*");
startActivityForResult(intent, 111); // 第二个参数是请求码
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
switch (requestCode) {
case 111: // 请求码
Log.d("Unity", "相册返回");
UnityPlayer.UnitySendMessage("Main Camera", "message", parseUri(data));
Log.d("unity", parseUri(data));
break;
}
}
}
public String parseUri(Intent data) {
Uri uri = data.getData();
String imagePath;
// 第二个参数是想要获取的数据
Cursor cursor = getContentResolver()
.query(uri, new String[]{MediaStore.Images.ImageColumns.DATA},
null, null, null);
if (cursor == null) {
imagePath = uri.getPath();
} else {
cursor.moveToFirst();
// 获取数据所在的列下标
int index = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
imagePath = cursor.getString(index); // 获取指定列的数据
cursor.close();
}
return imagePath; // 返回图片地址
}
}
8，AndroidMainFest 配置
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.test"
android:versionCode="1"
android:versionName="1.0" >
<application>
<activity android:name="com.example.test.MainActivity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<meta-data
android:name="unityplayer.UnityActivity" android:value="true" />
</activity>
</application>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
</manifest>9，安卓构建aar
10，导入Unity3d
打包构建出test_debug.arr，解压classes.jar 替换 libs的classes.jar ,再压缩成test_debug.arr
Plugins - Android - AndroidMainfest.xml
Plugins - Android - test_debug.arr
Unity3d代码部分
2种方式读取图片
1，UnityWebRequestTexture
2，使用文件流读取图片
void CallAndroid()
{
AndroidJavaClass jc = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
jo = jc.GetStatic<AndroidJavaObject>("currentActivity");
jo.Call("startPhoto");
Debug.Log("点击按钮");
}
public void message(string str)
{
ShowImage(str);
Debug.Log("安卓传来信息:" + str);
//StartCoroutine(LoadTexturePreview("file://" + str));
}
//使用UnityWebRequestTexture读取图片
IEnumerator LoadTexturePreview(string path)
{
UnityWebRequest uwr = UnityWebRequestTexture.GetTexture(path);
yield return uwr.SendWebRequest();
Debug.Log("图片地址:" + path);
if (uwr.isNetworkError || uwr.isHttpError)
{
Debug.Log("错误" + uwr.error);
}
else
{
Texture2D texture = DownloadHandlerTexture.GetContent(uwr);
// 图片显示在按钮上
Sprite sprite = Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height), new Vector2(.5f, .5f));
ImageView.sprite = sprite;
}
}
//使用文件流读取图片
private void ShowImage(string path)
{
FileStream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);
fileStream.Seek(0, SeekOrigin.Begin);
byte[] bye = new byte[fileStream.Length];
fileStream.Read(bye, 0, (int)bye.Length);
fileStream.Close();
fileStream.Dispose();
fileStream = null;
Texture2D texture = new Texture2D(100, 50);
texture.LoadImage(bye);
Sprite sprite = Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height), new Vector2(0.5f, 0.5f));
ImageView.sprite = sprite;
}
最终展示
完整工程源码
Unity3d打开手机相册完整工程实例-Unity3D文档类资源-CSDN下载
包含：Unity3d读取手机相册、unity打开手机相机、保存图片等功能
拓展
打包APK 报错
解决办法：
build.gralde里的classpath 指的是Android Studio的gradle插件版本。
'com.android.tools.build:gradle:3.5.2'
而gradle-wrapper.properties里的 distributionUrl才是指定的gradle版本！
distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip
Gradle是开源的自动化构建工具，而Gradle插件是google开发的在Android Studio中使用Gradle的插件。
参考网址：
Unity与Android的简单交互，Unity打开Android相册并调用（Unity2019以后）_不求甚解20018的博客-CSDN博客_unity打开手机相册
Unity Gradle Build
Intent.ACTION_PICK
Intent.ACTION_PICK - 时光正好, - 博客园
Unity自动打包-Android Studio - build.gradle详解