android - 我打开失败 : EACCES (Permission denied) error when I try write data to SD card in Android 5. 1，为什么？

Question

我需要保存一些数据到SD卡，我已经添加了权限 到AndroidManifest.xml文件，在Android 4.12 mobile上测试可以得到正确的结果。

但我在 Android 5.1 移动设备上测试它时出现 open failed: EACCES (Permission denied) 错误，为什么？

顺便说一句，我已经阅读了文章 Android 6.0 open failed: EACCES (Permission denied)和 Exception 'open failed: EACCES (Permission denied)' on Android , 但现在我的手机是三星 Android 5.1

代码

 private void ActionUploadFiles(Map<String, String> files,IHTTPSession session,String uploadFolder){

        try{
            Set<String> keys = files.keySet();

            for (String key:keys) {
                String location = files.get(key);
                File source = new File(location);

                String filename= session.getParms().get(key);
                filename=FilenameUtils.getName(filename);

                File target = new File(uploadFolder,filename);

                FileUtils.copyFile(source,target);
            }
        }
        catch (Exception e) {
            Utility.LogError("Upload Error: "+ e.getMessage());
        }
    }

AndroidManifest.xml

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

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <uses-permission android:name="com.android.vending.BILLING" />

build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.3"

    defaultConfig {      
        multiDexEnabled true

        applicationId "info.dodata.wifi"
        minSdkVersion 16
        targetSdkVersion 23
        versionCode 4
        versionName "1.04"
        archivesBaseName = "WiFiFileTransfer-V" + versionName
    }

    productFlavors {
        free {
            applicationId "info.dodata.wifi"
        }

        pro {
            applicationId "info.dodata.wifi.pro"
        }
    }


    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            buildConfigField "boolean", "IsDebugMode", "false"
        }

        debug {
            buildConfigField "boolean", "IsDebugMode", "true"
        }
    }

}

Answer 1

您缺少从 Android Lollipop 引入的运行时权限。您可以做的是启用权限。为此，请转到

设置 -> 应用程序 -> YOUR_APP -> 权限

并启用权限，然后进行测试。

要添加运行时权限，您可以在onCreate()中询问。

String[] permission ={Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE};

if(ContextCompat.checkSelfPermission(EditDisplayPicture.this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED
 && ContextCompat.checkSelfPermission(EditDisplayPicture.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {

    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        ActivityCompat.requestPermissions(YourActivity.this, permission, 1);
    }
} else proceedFurther();

然后像这样监听权限接受或拒绝，

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        proceedFurther();
    } else {
        Toast.makeText(YourActivity.this, "You need to give permission in order to proceed further.", Toast.LENGTH_SHORT).show();
    }
}