PS:Android10读取权限发生了变化,即使应用权限里有读写权限可能也无法进行读写,主要是
需要 android:requestLegacyExternalStorage="true"
//AndroidManifest.xml中
<application
android:requestLegacyExternalStorage="true"
/application>
读写文件需要在AndroidManifest.xml中增加权限
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
动态申请权限如下:
package com.example.myapplication;
import static android.content.pm.PackageManager.PERMISSION_GRANTED;
import androidx.appcompat.app.AppCompatActivity;
import android.Manifest;
import android.content.Intent;
import android.os.Bundle;
import android.os.Environment;
import android.provider.Settings;
import android.util.Log;
import com.unity3d.player.UnityPlayerActivity;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class MainActivity extends UnityPlayerActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main);
}
//动态申请权限
public boolean requestPermission() {
boolean isGranted = true;
if (android.os.Build.VERSION.SDK_INT >= 23) {
if (this.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PERMISSION_GRANTED) {
//如果没有写sd卡权限
isGranted = false;
}
if (!isGranted) {
this.requestPermissions(
new String[]{
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.WRITE_EXTERNAL_STORAGE
},
200);
}
}
return isGranted;
}
//创建文件-测试方法
public void CreatFile()
{
//Environment.getExternalStoragePublicDirectory("").toString() //"/storage/emulated/0"
String filePath = "/storage/emulated/0/Android/text33.txt";
File file = new File(filePath);
try {
if(!file.exists())
file.createNewFile();
FileOutputStream fos1 = new FileOutputStream(filePath);
String content="测试33";
fos1.write(content.getBytes());
fos1.flush();
fos1.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myapplication">
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:supportsRtl="true"
android:requestLegacyExternalStorage="true"
>
<activity
android:name="com.example.myapplication.MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
如果不太懂UnityPlayerActivity或打包aar请参考我的文章
Unity里调用如下:
//创建文件
string filepath = "/storage/emulated/0/Android/text33.txt";
button2.onClick.AddListener(() =>
{
AndroidJavaClass ajc = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
AndroidJavaObject jcontext = ajc.GetStatic<AndroidJavaObject>("currentActivity");
jcontext.Call("CreatFile", filepath);
});
//请求权限
button4.onClick.AddListener(() =>
{
AndroidJavaClass ajc = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
AndroidJavaObject jcontext = ajc.GetStatic<AndroidJavaObject>("currentActivity");
bool result= jcontext.Call<bool>("checkPermission");
Debug.LogError("请求权限:"+ result);
});
//读取文件
byte[] byt=File.ReadAllBytes(filepath);
String str=File.ReadAllText(filepath);
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附:Unity2019开始可以直接从Unity里请求权限,调用方式如下。亲测可用
using UnityEngine.Android;
Permission.RequestUserPermission("android.permission.WRITE_EXTERNAL_STORAGE");
AndroidManifest.xml里也需要声明一下权限清单
参考文章:
1. https://blog.csdn.net/msn465780/article/details/119057483 android 关于requestLegacyExternalStorage的使用
2. https://blog.csdn.net/u012539700/article/details/114930137?Android R(11)文件读写适配