android:requestLegacyExternalStorage="true"
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"
tools:ignore="ProtectedPermissions"/>
1、创建文件
String fileName = "my.txt";
File fs = new File(Environment.getExternalStorageDirectory() + "/msc/" + fileName);
安卓10内存文件
String downFileDir = context.getFilesDir().getAbsolutePath();
File dest = new File(downFileDir, tempName);
msc可要可不要 或者是"/"
创建图片文件
final File file = File.createTempFile(UUID.randomUUID().toString() + "", ".jpg");
2、删除文件
String ss = "/mnt/sdcard/my.txt";
// String ss = "/storage/emulated/0/Pictures/Screenshots/Screenshot_20190814-141238.jpg";
File file = new File(ss);
if (file.exists()){
file.delete();
/mnt/sdcard/ 等于 /storage/emulated/0/
3、string转为本地txt文件
String fileName = "my.txt";
File fs = new File(Environment.getExternalStorageDirectory()+"/" + fileName);
if (fs.exists()){
fs.delete();
String charset = "UTF-8";
// 写字符换转成字节流
try {
FileOutputStream outputStream = new FileOutputStream(fs);
OutputStreamWriter writer = new OutputStreamWriter(
outputStream, charset);
try {
writer.write("这是要保存的中文字符aaabbbb大范围sdfsdfsf");
} finally {
writer.close();
} catch (IOException e) {
e.printStackTrace();
文件夹不存在时——open failed: ENOENT (No such file or directory)。解决方法----创建文件夹即可
if (fs.exists()){
fs.delete();
}else {
fs.getParentFile().mkdirs();
4、读取本地txt文件，转为string
String fname = "/mnt/sdcard/my.txt";
private String loadTXTFromSDFile(String fname) {
String result=null;
try {
File f=new File(fname);
int length=(int)f.length();
byte[] buff=new byte[length];
FileInputStream fin=new FileInputStream(f);
fin.read(buff);
fin.close();
result=new String(buff,"UTF-8");
}catch (Exception e){
e.printStackTrace();
return result;
5、创建文件夹
// 文件存储
private File updateDir = null;
// 创建文件
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
updateDir = new File(Environment.getExternalStorageDirectory(), "data/cn.dlc.xiaoyao/msc2");
if (!updateDir.exists()) {
updateDir.mkdirs();
LogPlus.i("lgq","bbh-ss-video_savePath--333- ");
6、读取文件夹内容
File sceneFile = new File(Environment.getExternalStorageDirectory(), "data/cn.dlc.xiaoyao/msc1");
LogPlus.i("lgq","bbh-ss-video_savePath--- "+sceneFile.exists());
File[] files = sceneFile.listFiles();
if (null != files) {
for (int i = 0; i < files.length; i++) {
LogPlus.e("lgq文件夹下的文件：" + files[i].getName()+"......"+files[i].getPath()+"..."+getAudioFileVoiceTime(files[i].getPath()));
1、创建文件String fileName = "my.txt";File fs = new File(Environment.getExternalStorageDirectory() + "/msc/" + fileName);msc可要可不要 或者是"/"2、删除文件 String ss = "/mnt/sdcard/my....
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
impor...
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.RandomAccessFile;
public class FileOperati
首先要加入读写sd卡权限，否则创建会没有反应：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="and...
在此之前，需要获得读写存储器的权限，在AndroidManifest.xml添加如下： <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEM
1、创建文件夹
// 获取当前包名的files路径：/data/user/0/com.exa.myapplication/files
val PATH = this.filesDir.absolutePath
// 创建src目录和dst目录
// 【注】需要有PATH目录的权限才能创建子目录
// 若PATH文件夹权限为root权限，则
public static void writeFile(String FileName,String dirsPath,String content) throws IOException {
File dirs = new File(dirsPath);
File file = new File(dirsPath+ "/" + FileName + ".txt");
//如果文件夹不存在就创建文件夹
1.android在sd卡上创建一个txt文件，并且写入内容：
public static boolean saveTxt(String phoneNumber,Context context,String path){
//sd卡检测
String sdStatus = Environment.getExternalStorageState();
...
<!--SD卡读写的权限-->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EX
Android 将图片网址url转化为bitmap，drawable转bitmap，file转bitmap,bitmap转file，Bitmap转String，Uri转Bitmap
28176
m0_56884868:
Android 创建文件，删除文件，加载本地txt文件，string转txt文件，创建文件夹，读取文件夹，open failed: ENOENT
programmer_ada:
Android 图片识别、图像识别
alike914:
Android 申请权限，安卓11、安卓12文件权限，RxPermissions使用，android.permission.WRITE_SETTINGS
福州司马懿:
