企业网站推广策划书,吉安网站制作,vs2010做网站前台,做淘宝站外推广网站Android Q升级了文件系统#xff0c;访问文件不仅仅是说动态权限了#xff0c;有各种限制。权限什么的就不赘述了#xff0c;下面介绍一下在10以上的系统中访问文件。 
首先是打开文件管理器 /*** 打开文件管理器 存储卡和外接U盘都可以访问*/public void openFileManager()…Android Q升级了文件系统访问文件不仅仅是说动态权限了有各种限制。权限什么的就不赘述了下面介绍一下在10以上的系统中访问文件。 
首先是打开文件管理器 /*** 打开文件管理器 存储卡和外接U盘都可以访问*/public void openFileManager() {Intent intent  new Intent(Intent.ACTION_OPEN_DOCUMENT);intent.addCategory(Intent.CATEGORY_OPENABLE);intent.setType(text/*);startActivityForResult(intent, REQUEST_CODE_FILE);} 
这个setType可以根据自己的需要设置MIME类型设置要访问什么类型的文件。具体MIME可以参考MIME类型-CSDN博客 
然后会打开文件管理器这里面可以访问手机存储的文件或者外插U盘内的文件就根据自己需求选择文件就可以了。 选中的文件会在onActivityResult中返回 
Overrideprotected void onActivityResult(int requestCode, int resultCode, Nullable Intent data) {super.onActivityResult(requestCode, resultCode, data);if (resultCode  RESULT_OK  requestCode  REQUEST_CODE_FILE){//拿到需要解析的文件Uri uri  data.getData();String filePath FileHelper.getFileAbsolutePath(this,uri);if (!TextUtils.isEmpty(filePath)){parseFile  new File(filePath);binding.tvFileName.setText(parseFile.getName());readFile();}}} 
这里关键的一点就是把拿到的uri转换成filePath了转换成路径之后就可以读文件根据需求进行操作了。这个FileHelper转自Android打开系统文件管理器并获取选中文件的路径适配Android10及以上无法获取路径_intent.settype获取文件-CSDN博客 
package com.......utils;import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.os.FileUtils;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.provider.OpenableColumns;import androidx.annotation.RequiresApi;import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;/*** * Description:通过uri获取本地文件的绝对路径* p* */
public class FileHelper {/*** 根据Uri获取文件绝对路径解决Android4.4以上版本Uri转换** param context* param imageUri*/public static String getFileAbsolutePath(Context context, Uri imageUri) {if (context  null || imageUri  null) {return null;}if (android.os.Build.VERSION.SDK_INT  android.os.Build.VERSION_CODES.KITKAT) {return getRealFilePath(context, imageUri);}if (android.os.Build.VERSION.SDK_INT  android.os.Build.VERSION_CODES.KITKAT  android.os.Build.VERSION.SDK_INT  Build.VERSION_CODES.Q  DocumentsContract.isDocumentUri(context, imageUri)) {if (isExternalStorageDocument(imageUri)) {String docId  DocumentsContract.getDocumentId(imageUri);String[] split  docId.split(:);String type  split[0];if (primary.equalsIgnoreCase(type)) {return Environment.getExternalStorageDirectory()  /  split[1];}} else if (isDownloadsDocument(imageUri)) {String id  DocumentsContract.getDocumentId(imageUri);Uri contentUri  ContentUris.withAppendedId(Uri.parse(content://downloads/public_downloads), Long.valueOf(id));return getDataColumn(context, contentUri, null, null);} else if (isMediaDocument(imageUri)) {String docId  DocumentsContract.getDocumentId(imageUri);String[] split  docId.split(:);String type  split[0];Uri contentUri  null;if (image.equals(type)) {contentUri  MediaStore.Images.Media.EXTERNAL_CONTENT_URI;} else if (video.equals(type)) {contentUri  MediaStore.Video.Media.EXTERNAL_CONTENT_URI;} else if (audio.equals(type)) {contentUri  MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;}String selection  MediaStore.Images.Media._ID  ?;String[] selectionArgs  new String[]{split[1]};return getDataColumn(context, contentUri, selection, selectionArgs);}} // MediaStore (and general)if (android.os.Build.VERSION.SDK_INT  Build.VERSION_CODES.Q){return uriToFileApiQ(context,imageUri);}else if (content.equalsIgnoreCase(imageUri.getScheme())) {// Return the remote addressif (isGooglePhotosUri(imageUri)) {return imageUri.getLastPathSegment();}return getDataColumn(context, imageUri, null, null);}// Fileelse if (file.equalsIgnoreCase(imageUri.getScheme())) {return imageUri.getPath();}return null;}//此方法 只能用于4.4以下的版本private static String getRealFilePath(final Context context, final Uri uri) {if (null  uri) {return null;}final String scheme  uri.getScheme();String data  null;if (scheme  null) {data  uri.getPath();} else if (ContentResolver.SCHEME_FILE.equals(scheme)) {data  uri.getPath();} else if (ContentResolver.SCHEME_CONTENT.equals(scheme)) {String[] projection  {MediaStore.Images.ImageColumns.DATA};Cursor cursor  context.getContentResolver().query(uri, projection, null, null, null);//            Cursor cursor  context.getContentResolver().query(uri, new String[]{MediaStore.Images.ImageColumns.DATA}, null, null, null);if (null ! cursor) {if (cursor.moveToFirst()) {int index  cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);if (index  -1) {data  cursor.getString(index);}}cursor.close();}}return data;}/*** param uri The Uri to check.* return Whether the Uri authority is ExternalStorageProvider.*/private static boolean isExternalStorageDocument(Uri uri) {return com.android.externalstorage.documents.equals(uri.getAuthority());}/*** param uri The Uri to check.* return Whether the Uri authority is DownloadsProvider.*/private static boolean isDownloadsDocument(Uri uri) {return com.android.providers.downloads.documents.equals(uri.getAuthority());}private static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {Cursor cursor  null;String column  MediaStore.Images.Media.DATA;String[] projection  {column};try {cursor  context.getContentResolver().query(uri, projection, selection, selectionArgs, null);if (cursor ! null  cursor.moveToFirst()) {int index  cursor.getColumnIndexOrThrow(column);return cursor.getString(index);}} finally {if (cursor ! null) {cursor.close();}}return null;}/*** param uri The Uri to check.* return Whether the Uri authority is MediaProvider.*/private static boolean isMediaDocument(Uri uri) {return com.android.providers.media.documents.equals(uri.getAuthority());}/*** param uri The Uri to check.* return Whether the Uri authority is Google Photos.*/private static boolean isGooglePhotosUri(Uri uri) {return com.google.android.apps.photos.content.equals(uri.getAuthority());}/*** Android 10 以上适配 另一种写法* param context* param uri* return*/public static String getFileFromContentUri(Context context, Uri uri) {if (uri  null) {return null;}String filePath;String[] filePathColumn  {MediaStore.MediaColumns.DATA, MediaStore.MediaColumns.DISPLAY_NAME};ContentResolver contentResolver  context.getContentResolver();Cursor cursor  contentResolver.query(uri, filePathColumn, null,null, null);if (cursor ! null) {cursor.moveToFirst();try {filePath  cursor.getString(cursor.getColumnIndex(filePathColumn[0]));return filePath;} catch (Exception e) {} finally {cursor.close();}}return ;}/*** Android 10 以上适配* param context* param uri* return*/RequiresApi(api  Build.VERSION_CODES.Q)private static String uriToFileApiQ(Context context, Uri uri) {File file  null;//android10以上转换if (uri.getScheme().equals(ContentResolver.SCHEME_FILE)) {file  new File(uri.getPath());} else if (uri.getScheme().equals(ContentResolver.SCHEME_CONTENT)) {//把文件复制到沙盒目录ContentResolver contentResolver  context.getContentResolver();Cursor cursor  contentResolver.query(uri, null, null, null, null);if (cursor.moveToFirst()) {String displayName  cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));try {InputStream is  contentResolver.openInputStream(uri);File cache  new File(context.getExternalCacheDir().getAbsolutePath(), Math.round((Math.random()  1) * 1000)  displayName);FileOutputStream fos  new FileOutputStream(cache);FileUtils.copy(is, fos);file  cache;fos.close();is.close();} catch (IOException e) {e.printStackTrace();}}}return file.getAbsolutePath();}
}