在使用Xamarin Forms的Android 10.0(Q)应用程序中,我已在清单中正确设置了
<?xml version="1.0" encoding="utf-8"?>
<manifest **** />
<application *** ></application>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
</manifest>
我具有通过代码授予的权限
var permission = ActivityCompat.CheckSelfPermission(MainActivity.Instance, Manifest.Permission.WriteExternalStorage);
if (permission != Permission.Granted)
{
ActivityCompat.RequestPermissions(
MainActivity.Instance,
new[]
{
Manifest.Permission.WriteExternalStorage,
Manifest.Permission.ReadExternalStorage
}, 1);
}
然而,当我尝试在我的文档或图片文件夹中创建文件时,出现权限被拒绝错误:Java.IO.FileNotFoundException:'/storage/emulated/0/Documents/file.txt:打开失败:权限被拒绝)'我想念什么?
var folder= Android.OS.Environment.GetExternalStoragePublicDirectory(Android.OS.Environment.DirectoryDocuments);
folder.Mkdirs();
var filePath = Path.Combine(folder.AbsolutePath, filename);
// I get a permissions error here
using (var stream = new Java.IO.FileOutputStream(filePath))
{
await stream.WriteAsync(data).ConfigureAwait(false);
}
在您的应用与范围存储完全兼容之前,您可以根据应用的目标SDK级别或requestLegacyExternalStorage
清单属性暂时选择退出:
Google在Android Q:外部存储的过滤视图中具有一项新功能。快速解决方案是在AndroidManifest.xml文件中添加以下代码:
<manifest ... >
<!-- This attribute is "false" by default on apps targeting
Android 10 or higher. -->
<application android:requestLegacyExternalStorage="true" ... >
...
</application>
</manifest>