Unity读取Android外部文件的实现_Android

最近近到个小需求,需要读android件夹中的图片.在这里做一个记录.
首先读写部分,这里以图片为例子:

一读写部分

写入部分:需要注意的是因为只有这个地址支持外部读写,所以这里用到的地址都以 :application.persistentdatapath为地址起始.

private texture2d __capturecamera()
    {
        rendertexture rt = m_renget;
        rendertexture.active = rt;
        texture2d screenshot = new texture2d(256, 256, textureformat.rgb24, false);
        screenshot.readpixels(new rect(0, 0, 256, 256), 0, 0);
        screenshot.apply();
        byte[] bytes = screenshot.encodetopng();
        string filename = application.persistentdatapath + "/house1.jpg";
        system.io.file.writeallbytes(filename, bytes);
        return screenshot;
    }

读取部分:为了方便测试这里使用了inputfiled组件为了方便随时调整地址:

	private void __on3()
    {
   		 input.text = application.persistentdatapath;
        string path = "file:///" + input.text;
        startcoroutine(loadimage(path, bb));
    }
    private void bb(object obj)
    {
        texture2d tex = obj as texture2d;
        rw.texture = tex;
    }
    public ienumerator loadimage(string path, action<object> callback)
    {

        debug.log("读取地址:"+path);
        using (www www = new www(path))
        {
            yield return www;
            if (www.error != null)
            {
                if (callback != null)
                {
                    //加载失败将加载本地默认图片
                    //callback(resources.load(assetpathconfig.default_image) as texture2d);
                    //debug.log("失败");
                    debug.log("失败");
                }
            }
            else
            {
                if (www.isdone)
                {
                    if (callback != null)
                    {
                        debug.log("成功");
                        callback(www.texture);
                    }
                }
            }
        }
    }

二权限申请

权限获取分为三个部分
版本设置需要将android调整到较高版本(不一定)

在这里插入图片描述

外部读写设置然后是将project setting > othersettings > write permission 设置为 extemal(sdcard)
使用可以方位指定文件夹外的文件

在这里插入图片描述

权限配置然后勾选project setting > publishing settings > build > custom main manifest
此时将在自动在plugins 下生成android/androidmanifest文件

在些可添加额外的权限

在这里插入图片描述

<?xml version="1.0" encoding="utf-8"?>
<manifest
    xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.unity3d.player"
    xmlns:tools="http://schemas.android.com/tools">

  <uses-permission android:name="android.permission.write_external_storage" />
  <uses-permission android:name="android.permission.read_external_storage" />
  
    <application>
        <activity android:name="com.unity3d.player.unityplayeractivity"
                  android:theme="@style/unitythemeselector">
            <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>
</manifest>

申请权限只需要在游戏开始调用requestpermissions方法即可完成权限申请

//申请多个权限
    private void requestpermissions()
    {
        if (m_stringbuilder == null)
        {
            m_stringbuilder = new stringbuilder();
        }
        else
        {
            m_stringbuilder.clear();
        }
        m_isgetallpermission = false;

        //申请回调
        m_permissioncallbacks = new permissioncallbacks();
        m_permissioncallbacks.permissiondenied += onpermissiondenied;
        m_permissioncallbacks.permissiongranted += onpermissiongranted;
        m_permissioncallbacks.permissiondeniedanddontaskagain += onpermissiondeniedanddontaskagain;

        //申请权限组
        string[] permissions =
        {
            permission.externalstorageread,
            permission.externalstoragewrite,
            // 添加其他权限
        };

        //执行申请多个权限
        permission.requestuserpermissions(permissions, m_permissioncallbacks);

    }

    //申请权限被拒绝
    private void onpermissiondenied(string permission)
    {
        debug.log($"onpermissiondenied:{permission}");
    }

    //申请权限成功
    /// <param name="permission"></param>
    private void onpermissiongranted(string permission)
    {
        debug.log($"onpermissiongranted:{permission}");
        //检查权限是否全部通过
        if (permission.hasuserauthorizedpermission(permission.externalstorageread) &&
            permission.hasuserauthorizedpermission(permission.externalstoragewrite))
        {
            //防止多次回调
            if (!m_isgetallpermission)
            {
                m_isgetallpermission = true;
                //在这里处理权限通过的逻辑
                //do something
                debug.log("权限申请全部通过");
            }
        }
    }

    //申请权限被拒绝,且不再询问
    private void onpermissiondeniedanddontaskagain(string permission)
    {
        debug.log ($"onpermissiondeniedanddontaskagain:{permission}");
    }