Android SAF DocumentFile-检查路径是否存在，而不在每个文件夹级别创建每个DocumentFile

如果您想检查“/folder/subfolder/subsubfolder/test/test.txt”文件是否存在，请执行以下操作：

DocumentFile sdCard = ...; // i have already retrieved the sd card root with the users help via SAF

String path = "<SD CARD>/folder/subfolder/subsubfolder/test/test.txt";
List<String> pathParts = Arrays.asList(path.split("/"));
DocumentFile doc = sdCard;
// go through all folders, starting at sd card, to check, if the desired file exists
for (int i = 1; i < pathParts.size(); i++)
{
    DocumentFile nextDoc = doc.findFile(pathParts.get(i));
    if (nextDoc != null)
        doc = nextDoc;
    else
    {
        doc = null;
        break;
    }
}

if (doc == null)
{
    // file does not exist
}
else
{
    // file does exist
}

DocumentFile sdCard=…；//我已经通过SAF在用户帮助下检索了sd卡根目录
字符串路径=“/folder/subfolder/subsubfolder/test/test.txt”；
List pathParts=Arrays.asList（path.split（“/”）；
DocumentFile doc=sdCard；
//检查所有文件夹，从sd卡开始，检查所需文件是否存在
对于（int i=1；i

这是非常缓慢的，有没有更快的方法至少可以检查sd卡上是否存在文件？我不想创建每个

文档文件

只是为了检查路径是否存在

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    Uri uri = data.getData();
    DocumentFile pickedDir = DocumentFile.fromTreeUri(MainActivity.this, uri);
    String id = DocumentsContract.getTreeDocumentId(uri); 

    /* id is :  "primary:namefolder" if user select a "namefolder" from internal storage. 
     or CABB-5641 if user select external storage,
    */

    id = id + "/folder/subfolder/subsubfolder/test/test.txt";  // your path,  you must to ensure is consistent with that chosen by the user,

    Uri childrenUri = DocumentsContract.buildDocumentUriUsingTree(uri,id);
    DocumentFile chhildfile = DocumentFile.fromSingleUri(MainActivity.this,childrenUri);

    if(chhildfile != null && chhildfile.exists()){
        Log.d("laporan file", "file ini ada");
    }
}

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我不是专家，我不知道这是否适用于大多数android，但我已经在android emulator和华硕Zenfone 5中进行了尝试，希望这将有助于

如果您有解决方案的话？没有比我问题中发布的更好的解决方案了……谢谢！我在这上面花了8个小时！SAF真是一团糟！