如何列出我的android设备中的所有pdf文件

我找到了关于如何获取所有图像的代码

有人能告诉我如何在内部存储和外部存储中只获取.pdf文件吗？

final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
    final String orderBy = MediaStore.Images.Media._ID;
    //Stores all the images from the gallery in Cursor
    Cursor cursor = getContentResolver().query(
            MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null,
            null, orderBy);
    //Total number of images
    int count = cursor.getCount();

    //Create an array to store path to all the images
    String[] arrPath = new String[count];

    for (int i = 0; i < count; i++) {
        cursor.moveToPosition(i);
        int dataColumnIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
        //Store the path of the image
        arrPath[i]= cursor.getString(dataColumnIndex);
        Log.i("PATH", arrPath[i]);
    } 

final String[]columns={MediaStore.Images.Media.DATA，MediaStore.Images.Media.\u ID}；
最终字符串orderBy=MediaStore.Images.Media.\u ID；
//将库中的所有图像存储在光标中
Cursor Cursor=getContentResolver（）.query(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI，列，null，
null，orderBy）；
//图像总数
int count=cursor.getCount（）；
//创建一个数组来存储所有图像的路径
字符串[]arrPath=新字符串[计数]；
for（int i=0；i

可能的解决方案是转到每个文件夹，检查.pdf是否存在。如果存在，您可以对该文件执行任何操作

public void Search_Dir(File dir) {
  String pdfPattern = ".pdf";

File FileList[] = dir.listFiles();

if (FileList != null) {
    for (int i = 0; i < FileList.length; i++) {

        if (FileList[i].isDirectory()) {
            Search_Dir(FileList[i]);
        } else {
          if (FileList[i].getName().endsWith(pdfPattern)){
                              //here you have that file.

          }
        }
    }
  }    
}

您可以尝试以下方法： 1.）

private ListView-mListView；
私有ArrayList mAttachmentList=新ArrayList（）；
private ArrayList fileList=new ArrayList（）；
mListView=（ListView）findViewById（R.id.listAttachments）；
File dir=新文件（Environment.getExternalStorageDirectory（）.getAbsolutePath（））；
获取文件（dir）；
setAdapter（）；

(二)

public ArrayList getfile（文件目录）{
文件listFile[]=dir.listFiles（）；
if（listFile！=null&&listFile.length>0）{
for（int i=0；i

(三)

private void setAdapter（）
{
AttachmentAdapter itemsAdapter=新的AttachmentAdapter（AttachmentFileList.this）；
ArrayList=新建ArrayList（）；
itemsAdapter.setData（mAttachmentList）；
mListView.setAdapter（itemsAdapter）；
}

您应该能够通过Android系统列出所有这些文件，而无需手动查看设备的所有文件夹

例如：

String selection = "_data LIKE '%.pdf'"
try (Cursor cursor = getApplicationContext().getContentResolver().query(MediaStore.Files.getContentUri("external"), null, selection, null, "_id DESC")) {
    if (cursor== null || cursor.getCount() <= 0 || !cursor.moveToFirst()) {
        // this means error, or simply no results found
        return;
    }
    do {
        // your logic goes here
    } while (cursor.moveToNext());
}

String selection=“\u类似于“%.pdf”的数据”
try（Cursor Cursor=getApplicationContext（）.getContentResolver（）.query（MediaStore.Files.getContentUri（“外部”），null，selection，null，“\u id DESC”））{
if（cursor==null | | cursor.getCount（）如果使用Kotlin，我认为这是最简洁的方法

val ROOT_DIR = Environment.getExternalStorageDirectory().absolutePath
val ANDROID_DIR = File("$ROOT_DIR/Android")
val DATA_DIR = File("$ROOT_DIR/data")
File(ROOT_DIR).walk()
               // befor entering this dir check if
               .onEnter{ !it.isHidden // it is not hidden
                         && it != ANDROID_DIR // it is not Android directory
                         && it != DATA_DIR // it is not data directory
                && !File(it, ".nomedia").exists() //there is no .nomedia file inside
               }.filter { it.extension == "pdf" }
               .toList()

您可以对java8流或RxJava执行类似的操作，您可以使用以下内容列出
PDF
文档（这不会列出设备上未知的PDF）

如果您想要的不仅仅是
PDF
文件，如
DocX
，您可以稍微更改
where
子句以满足您的需要：

String whereClause = MediaStore.Files.FileColumns.MIME_TYPE + " IN ('" + mimeType + "')"
          + " OR " + MediaStore.Files.FileColumns.MIME_TYPE + " LIKE 'application/vnd%'"

然后循环遍历光标以检索文档：

int idCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns._ID);
int mimeCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.MIME_TYPE);
int addedCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATE_ADDED);
int modifiedCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATE_MODIFIED);
int nameCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DISPLAY_NAME);
int titleCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.TITLE);
int sizeCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.SIZE);

if (cursor.moveToFirst()) {
    do {
        Uri fileUri = Uri.withAppendedPath(MediaStore.Files.getContentUri("external"), cursor.getString(idCol));
        String mimeType = cursor.getString(mimeCol);
        long dateAdded = cursor.getLong(addedCol);
        long dateModified = cursor.getLong(modifiedCol);
        // ...
    } while (cursor.moveToNext());
}

您是否尝试过解决此问题？如果尝试过，请在问题中包含您的代码和研究，以显示哪些内容对您不起作用。如果没有，您应该先尝试自己解决，然后将代码和研究发布在此处。这也使您的问题更容易让其他人回答！可能存在重复的问题
String selection = "_data LIKE '%.pdf'"
try (Cursor cursor = getApplicationContext().getContentResolver().query(MediaStore.Files.getContentUri("external"), null, selection, null, "_id DESC")) {
    if (cursor== null || cursor.getCount() <= 0 || !cursor.moveToFirst()) {
        // this means error, or simply no results found
        return;
    }
    do {
        // your logic goes here
    } while (cursor.moveToNext());
}

val ROOT_DIR = Environment.getExternalStorageDirectory().absolutePath
val ANDROID_DIR = File("$ROOT_DIR/Android")
val DATA_DIR = File("$ROOT_DIR/data")
File(ROOT_DIR).walk()
               // befor entering this dir check if
               .onEnter{ !it.isHidden // it is not hidden
                         && it != ANDROID_DIR // it is not Android directory
                         && it != DATA_DIR // it is not data directory
                && !File(it, ".nomedia").exists() //there is no .nomedia file inside
               }.filter { it.extension == "pdf" }
               .toList()

// Use android.provider.MediaStore

String[] projection = {
    MediaStore.Files.FileColumns._ID,
    MediaStore.Files.FileColumns.MIME_TYPE,
    MediaStore.Files.FileColumns.DATE_ADDED,
    MediaStore.Files.FileColumns.DATE_MODIFIED,
    MediaStore.Files.FileColumns.DISPLAY_NAME,
    MediaStore.Files.FileColumns.TITLE,
    MediaStore.Files.FileColumns.SIZE,
};

String mimeType = "application/pdf";

String whereClause = MediaStore.Files.FileColumns.MIME_TYPE + " IN ('" + mimeType + "')";
String orderBy = MediaStore.Files.FileColumns.SIZE + " DESC";
Cursor cursor = getContentResolver().query(MediaStore.Files.getContentUri("external"),
                                           projection,
                                           whereClause,
                                           null,
                                           orderBy);

String whereClause = MediaStore.Files.FileColumns.MIME_TYPE + " IN ('" + mimeType + "')"
          + " OR " + MediaStore.Files.FileColumns.MIME_TYPE + " LIKE 'application/vnd%'"

int idCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns._ID);
int mimeCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.MIME_TYPE);
int addedCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATE_ADDED);
int modifiedCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATE_MODIFIED);
int nameCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DISPLAY_NAME);
int titleCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.TITLE);
int sizeCol = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.SIZE);

if (cursor.moveToFirst()) {
    do {
        Uri fileUri = Uri.withAppendedPath(MediaStore.Files.getContentUri("external"), cursor.getString(idCol));
        String mimeType = cursor.getString(mimeCol);
        long dateAdded = cursor.getLong(addedCol);
        long dateModified = cursor.getLong(modifiedCol);
        // ...
    } while (cursor.moveToNext());
}