Android 10 SDK版本29无法在内存根目录创建文件夹？
查阅文档得知android 10添加了沙盒机制
我们应该如何解决这个问题呢？
解决方法
1）直接跳过沙盒特性，沿用以往的做法
在manifest文件的application节点中添加
android:requestLegacyExternalStorage="true"
2）根据新特性，实现Android10的适配
public static String getSDPath(Context context) {
File sdDir = null;
boolean sdCardExist = Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED);// 判断sd卡是否存在
if (sdCardExist) {
if (Build.VERSION.SDK_INT >= 29) {
//Android10之后
sdDir = context.getExternalFilesDir(null);//获取应用所在根目录/Android/data/your.app.name/file/ 也可以根据沙盒机制传入自己想传的参数，存放在指定目录
} else {
sdDir = Environment.getExternalStorageDirectory();// 获取SD卡根目录
}
} else {
sdDir = Environment.getRootDirectory();// 获取跟目录
}
return sdDir.toString();
}
获取指定沙盒文件夹路径请参阅：
//废弃方法
//不再用以下代码获取文件根目录了
Environment.getExternalStorageDirectory();
Environment.getExternalStoragePublicDirectory();
//获取沙盒下的文件目录
//沙盒下的图片文件夹
File filePictures = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
//Environment下的文件夹名称常量
//只需要调用，不需要创建，如果手机中没有对应的文件夹，则系统会自动生成
//以下为源码中的各个文件夹名称描述
/**
* Standard directory in which to place any audio files that should be
* in the regular list of music for the user.
* This may be combined with
* {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS},
* {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_MUSIC = "Music";
/**
* Standard directory in which to place any audio files that should be
* in the list of podcasts that the user can select (not as regular
* music).
* This may be combined with {@link #DIRECTORY_MUSIC},
* {@link #DIRECTORY_NOTIFICATIONS},
* {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_PODCASTS = "Podcasts";
/**
* Standard directory in which to place any audio files that should be
* in the list of ringtones that the user can select (not as regular
* music).
* This may be combined with {@link #DIRECTORY_MUSIC},
* {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS}, and
* {@link #DIRECTORY_ALARMS} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_RINGTONES = "Ringtones";
/**
* Standard directory in which to place any audio files that should be
* in the list of alarms that the user can select (not as regular
* music).
* This may be combined with {@link #DIRECTORY_MUSIC},
* {@link #DIRECTORY_PODCASTS}, {@link #DIRECTORY_NOTIFICATIONS},
* and {@link #DIRECTORY_RINGTONES} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_ALARMS = "Alarms";
/**
* Standard directory in which to place any audio files that should be
* in the list of notifications that the user can select (not as regular
* music).
* This may be combined with {@link #DIRECTORY_MUSIC},
* {@link #DIRECTORY_PODCASTS},
* {@link #DIRECTORY_ALARMS}, and {@link #DIRECTORY_RINGTONES} as a series
* of directories to categories a particular audio file as more than one
* type.
*/
public static String DIRECTORY_NOTIFICATIONS = "Notifications";
/**
* Standard directory in which to place pictures that are available to
* the user. Note that this is primarily a convention for the top-level
* public directory, as the media scanner will find and collect pictures
* in any directory.
*/
public static String DIRECTORY_PICTURES = "Pictures";
/**
* Standard directory in which to place movies that are available to
* the user. Note that this is primarily a convention for the top-level
* public directory, as the media scanner will find and collect movies
* in any directory.
*/
public static String DIRECTORY_MOVIES = "Movies";
/**
* Standard directory in which to place files that have been downloaded by
* the user. Note that this is primarily a convention for the top-level
* public directory, you are free to download files anywhere in your own
* private directories. Also note that though the constant here is
* named DIRECTORY_DOWNLOADS (plural), the actual file name is non-plural for
* backwards compatibility reasons.
*/
public static String DIRECTORY_DOWNLOADS = "Download";
/**
* The traditional location for pictures and videos when mounting the
* device as a camera. Note that this is primarily a convention for the
* top-level public directory, as this convention makes no sense elsewhere.
*/
public static String DIRECTORY_DCIM = "DCIM";
/**
* Standard directory in which to place documents that have been created by
* the user.
*/
public static String DIRECTORY_DOCUMENTS = "Documents";
/**
* Standard directory in which to place screenshots that have been taken by
* the user. Typically used as a secondary directory under
* {@link #DIRECTORY_PICTURES}.
*/
public static String DIRECTORY_SCREENSHOTS = "Screenshots";
/**
* Standard directory in which to place any audio files which are
* audiobooks.
*/
public static String DIRECTORY_AUDIOBOOKS = "Audiobooks";