如何在Android 4.1.2上的外部存储公共目录文档中保存文件 [英] How to save files in External Storage Public Directory DOCUMENTS on Android 4.1.2

问题描述

我想在我的Android 4.1.2智能手机上将文件保存在documents目录中.

i want to save a file on my Android 4.1.2 smartphone in the documents directory.

此代码段:

File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS),"test.txt");

引发此异常:

E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NoSuchFieldError: android.os.Environment.DIRECTORY_DOCUMENTS

这是可行的:

File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS),"test.txt"); 

但是我想将文件保存在我的文档目录中，而不是下载中.我已阅读过DIRECTORY_DOCUMENTS，仅在Android 4.4及更高版本中可用.但是我的智能手机上还有一个文档目录.因此，没有解决方案将其保存在文档中吗?

But i want to save my file in my documents directory, not in downloads. Ive read DIRECTORY_DOCUMENTS is only available in Android 4.4 and higher. But there is also a documents direcotry on my smartphone. So, is there no solution to save it in documents?

寻求答案

鹅卵石

推荐答案

您无法访问DIRECTORY_DOCUMENTS，因为它在Android 4.1.2中不存在.这意味着，尽管您的外部存储中有一个Documents目录，但DIRECTORY_DOCUMENTS并不指向该目录(因为它不存在).要解决此问题，必须创建目录(如果不存在)并手动获取该文件夹的路径.

You are not able to access DIRECTORY_DOCUMENTS becuase it is not there in Android 4.1.2. Which means, though there is a Documents directory in your external storage, it is not pointed to by DIRECTORY_DOCUMENTS (since it is non-existent). To solve this, you have to create the directory if it is not present and get the path to that folder manually.

File docsFolder = new File(Environment.getExternalStorageDirectory() + "/Documents");
boolean isPresent = true;
if (!docsFolder.exists()) {
    isPresent = docsFolder.mkdir();
}
if (isPresent) {
    File file = new File(docsFolder.getAbsolutePath(),"test.txt"); 
} else {
    // Failure
}

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