Android交互示例

从Unity2018开始，Unity支持使用Java源码文件作为插件在Unity工程中使用。在构建Android时会编译这些源码（该功能依赖于Gradle构建系统）

1. 创建Java文件

Assets->Plugins->Android->UnityTools.java 

注意：文件名必须和类名一致

package com.UnityPackage;

import java.io.File;  
import android.os.Environment;  
import android.os.StatFs;

public class UnityTools
{
    public static long GetFreeStorageSpace()
    {
        try
        {
            File file = Environment.getDataDirectory();
            StatFs stat = new StatFs(file.getPath());
            return stat .getAvailableBytes(); //VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN_MR2
        }
        catch (Exception e)
        {
        }
        return -1;
    }
}

2. 创建C#文件

using System;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using UnityEngine;

public class UnityAndroidTools
{
    public static long GetFreeStorageSpace()
    {
        try
        {
            AndroidJavaObject javaObj = new AndroidJavaObject("com.UnityPakcage.UnityTools");
            return javaObj.CallStatic<long>("GetFreeStorageSpace");
        }
        catch(Exception e)
        {
            Debug.LogError(e);
        }
        return -1;
    }
}

 

Unity和Andorid回调的交互

1. Java类

package com.UnityPackage;

import com.arthenica.mobileffmpeg.Config;
import com.arthenica.mobileffmpeg.FFmpeg;
import com.arthenica.mobileffmpeg.ExecuteCallback;
import com.unity3d.player.UnityPlayer;

public class UnityTester
{
    public static long AsyncRun(final String command)
    {
        long executionId = FFmpeg.executeAsync(command, new ExecuteCallback()
        {
            @Override
            public void apply(final long executionId, final int returnCode) {
                UnityPlayer.UnitySendMessage("MainCamera", "RunCallback", String.valueOf(returnCode));
            }
        });

        return executionId;
    }
}

2. C#类

注意：BindTester脚本一定要挂在一个名叫"MainCamera"的GameObject对象上。

using System;
using System.IO;
using System.Text;
using UnityEngine;public class BindTester : MonoBehaviour
{
    public void RunCallback(string errorCode)
    {
        Debug.Log($"异步执行结果：{errorCode}");
    }
}