diff --git a/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/ExplorerConfig.java b/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/ExplorerConfig.java
index e0a432c7..7bf6469d 100644
--- a/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/ExplorerConfig.java
+++ b/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/ExplorerConfig.java
@@ -41,7 +41,7 @@ public class ExplorerConfig implements Serializable {
     private File rootDir;
     private boolean loadAsync;
     private String[] allowExtensions = null;
-    private int explorerMode = ExplorerMode.DIRECTORY;
+    private int explorerMode = ExplorerMode.FILE;
     private boolean showHomeDir = true;
     private boolean showUpDir = true;
     private boolean showHideDir = true;
diff --git a/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/adapter/FileAdapter.java b/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/adapter/FileAdapter.java
index 2f51039b..e0986ef7 100644
--- a/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/adapter/FileAdapter.java
+++ b/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/adapter/FileAdapter.java
@@ -268,7 +268,7 @@ private List<FileEntity> loadDataSync(File dir) {
      * 列出指定目录下的所有子目录
      */
     private List<File> listFiles(File startDir, FileFilter fileFilter) {
-        DialogLog.print(String.format("list dir %s", startDir));
+        DialogLog.print(String.format("list dir %s by filter %s", startDir, fileFilter.getClass().getName()));
         if (!startDir.isDirectory()) {
             return new ArrayList<>();
         }
diff --git a/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/filter/SimpleFilter.java b/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/filter/SimpleFilter.java
index 72da6e3b..de6aefb1 100644
--- a/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/filter/SimpleFilter.java
+++ b/FilePicker/src/main/java/com/github/gzuliyujiang/filepicker/filter/SimpleFilter.java
@@ -13,8 +13,12 @@
 
 package com.github.gzuliyujiang.filepicker.filter;
 
+import android.text.TextUtils;
+
 import androidx.annotation.Nullable;
 
+import com.github.gzuliyujiang.dialog.DialogLog;
+
 import java.io.File;
 import java.io.FileFilter;
 import java.util.Arrays;
@@ -35,33 +39,51 @@ public SimpleFilter(boolean isOnlyDir, @Nullable String[] allowExtensions) {
     @Override
     public boolean accept(File pathname) {
         if (pathname == null) {
+            DialogLog.print("Filter>>>pathname is null");
             return false;
         }
+        if (pathname.isDirectory()) {
+            DialogLog.print("Filter>>>pathname is directory: " + pathname);
+            return true;
+        }
         if (isOnlyDir && pathname.isFile()) {
+            DialogLog.print("Filter>>>except directory but is file: " + pathname);
             return false;
         }
         if (allowExtensions == null || allowExtensions.length == 0) {
+            DialogLog.print("Filter>>>allow extensions is empty: " + pathname);
             return true;
         }
         //返回当前目录所有以某些扩展名结尾的文件
         String extension = getExtension(pathname.getPath());
-        return Arrays.toString(allowExtensions).contains(extension);
+        DialogLog.print("Filter>>>extension of " + pathname + ": " + extension);
+        boolean contains = false;
+        for (String allowExtension : allowExtensions) {
+            if (TextUtils.isEmpty(allowExtension) || allowExtension.contains(extension)) {
+                contains = true;
+                break;
+            }
+        }
+        DialogLog.print("Filter>>>allow extensions is " + Arrays.toString(allowExtensions) + ", contains: " + contains);
+        return contains;
     }
 
     private String getExtension(String path) {
         if (path == null) {
             return "";
         }
+        String ext = "";
         int slashPos = path.lastIndexOf(File.separator);
         if (slashPos != -1) {
             path = path.substring(slashPos);
         }
         int dotPos = path.lastIndexOf('.');
-        if (0 <= dotPos) {
-            return path.substring(dotPos + 1);
+        if (dotPos != -1) {
+            ext = path.substring(dotPos + 1);
         } else {
-            return "";
+            ext = path;
         }
+        return ext;
     }
 
 }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 0b50c2b9..5c60f93c 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -15,6 +15,11 @@
     xmlns:tools="http://schemas.android.com/tools"
     package="com.github.gzuliyujiang.fallback">
 
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+    <uses-permission
+        android:name="android.permission.MANAGE_EXTERNAL_STORAGE"
+        tools:ignore="ScopedStorage" />
+
     <application
         android:name=".DemoApp"
         android:allowBackup="false"
diff --git a/app/src/main/java/com/github/gzuliyujiang/fallback/activity/FileExplorerFragment.java b/app/src/main/java/com/github/gzuliyujiang/fallback/activity/FileExplorerFragment.java
index 87c03d57..c72bf370 100644
--- a/app/src/main/java/com/github/gzuliyujiang/fallback/activity/FileExplorerFragment.java
+++ b/app/src/main/java/com/github/gzuliyujiang/fallback/activity/FileExplorerFragment.java
@@ -61,6 +61,7 @@ public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup c
     @Override
     public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
+        FileExplorer fileExplorer = view.findViewById(R.id.fileExplorer);
         ExplorerConfig config = new ExplorerConfig(requireContext());
         config.setRootDir(new File("sdcard"));
         config.setLoadAsync(true);
@@ -68,7 +69,7 @@ public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceStat
         config.setShowHomeDir(false);
         config.setShowUpDir(false);
         config.setShowHideDir(false);
-        FileExplorer fileExplorer = view.findViewById(R.id.fileExplorer);
+        //config.setAllowExtensions(new String[]{".txt", ".jpg"});
         fileExplorer.load(config);
     }
 
diff --git a/app/src/main/java/com/github/gzuliyujiang/fallback/activity/FilePickerActivity.java b/app/src/main/java/com/github/gzuliyujiang/fallback/activity/FilePickerActivity.java
index 175d794a..845fc4a8 100644
--- a/app/src/main/java/com/github/gzuliyujiang/fallback/activity/FilePickerActivity.java
+++ b/app/src/main/java/com/github/gzuliyujiang/fallback/activity/FilePickerActivity.java
@@ -13,8 +13,12 @@
 
 package com.github.gzuliyujiang.fallback.activity;
 
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
+import android.provider.Settings;
 import android.view.View;
 import android.widget.Toast;
 
@@ -42,6 +46,7 @@ public class FilePickerActivity extends BackAbleActivity implements OnFilePicked
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_picker_file);
+        FileExplorer fileExplorer = findViewById(R.id.file_picker_explorer);
         ExplorerConfig config = new ExplorerConfig(this);
         config.setRootDir(Environment.getExternalStorageDirectory());
         config.setLoadAsync(true);
@@ -49,7 +54,7 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
         config.setShowHomeDir(true);
         config.setShowUpDir(true);
         config.setShowHideDir(true);
-        FileExplorer fileExplorer = findViewById(R.id.file_picker_explorer);
+        config.setAllowExtensions(new String[]{".txt", ".jpg"});
         fileExplorer.load(config);
     }
 
@@ -58,6 +63,19 @@ public void onFilePicked(@NonNull File file) {
         Toast.makeText(getApplicationContext(), file.getAbsolutePath(), Toast.LENGTH_SHORT).show();
     }
 
+    public void onPermission(View view) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            if (Environment.isExternalStorageManager()) {
+                Toast.makeText(getApplicationContext(), "isExternalStorageManager==true", Toast.LENGTH_SHORT).show();
+            } else {
+                Intent intent = new Intent(Settings.ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION);
+                intent.setData(Uri.parse("package:" + getApplicationContext().getPackageName()));
+                startActivity(intent);
+            }
+        }
+        Toast.makeText(getApplicationContext(), "当前系统版本不支持", Toast.LENGTH_SHORT).show();
+    }
+
     public void onFilePick(View view) {
         ExplorerConfig config = new ExplorerConfig(this);
         config.setRootDir(getExternalFilesDir(null));
diff --git a/app/src/main/res/layout/activity_picker_file.xml b/app/src/main/res/layout/activity_picker_file.xml
index 6c2ff76b..43279897 100644
--- a/app/src/main/res/layout/activity_picker_file.xml
+++ b/app/src/main/res/layout/activity_picker_file.xml
@@ -24,6 +24,12 @@
 
         <include layout="@layout/layout_title_bar" />
 
+        <Button
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:onClick="onPermission"
+            android:text="所有文件访问权限" />
+
         <Button
             android:layout_width="match_parent"
             android:layout_height="wrap_content"