以编程方式获取外部SD卡路径

Question

我的平板电脑有内置存储，USB存储，外置SD卡存储。我需要访问外置SD卡。我无法得到正确答案。

Answer 1

您可以通过adb访问SD卡，如：

adb shell cd \$EXTERNAL_STORAGE

或者您可以查看getExternalStorageState()。

Answer 2

如果您有SD卡，可以使用Environment.getExternalStorageDirectory()获取SD卡的根路径。

Answer 3

在onActivityResult中，您将获得数据

Uri selectedImageUri = data.getData();
String path = App.getPath(getActivity(), selectedImageUri);

使用此方法获取文件路径

@TargetApi(19)
@SuppressLint("NewApi")
public static String getPath(final Activity context, final Uri uri) {

    final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

    // DocumentProvider
    if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
        // ExternalStorageProvider
        if (isExternalStorageDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            if ("primary".equalsIgnoreCase(type)) {
                return Environment.getExternalStorageDirectory() + "/"
                        + split[1];
            }

            // TODO handle non-primary volumes
        } else if (isDownloadsDocument(uri)) {

            final String id = DocumentsContract.getDocumentId(uri);
            final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://downloads/public_downloads"),
                    Long.valueOf(id));

            return getDataColumn(context, contentUri, null, null);
        }

        // MediaProvider
        else if (isMediaDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final 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;
            }

            final String selection = "_id=?";
            final String[] selectionArgs = new String[]{split[1]};

            return getDataColumn(context, contentUri, selection,
                    selectionArgs);
        } else if ("content".equalsIgnoreCase(uri.getScheme())) {

            // Return the remote address
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();

            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }
    }
    if (uri == null) {
        // TODO perform some logging or show user feedback
        return null;
    } else {
        // try to retrieve the image from the media store first
        // this will only work for images selected from gallery
        String[] projection = {MediaStore.Images.Media.DATA};
        Cursor cursor = context.managedQuery(uri, projection, null, null, null);
        if (cursor != null) {
            int column_index = cursor
                    .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }
        // this is our fallback here
        return uri.getPath();
    }
}

public static boolean isMediaDocument(Uri uri) {
    return "com.android.providers.media.documents".equals(uri
            .getAuthority());
}

public static boolean isDownloadsDocument(Uri uri) {
    return "com.android.providers.downloads.documents".equals(uri
            .getAuthority());
}

public static boolean isGooglePhotosUri(Uri uri) {
    return "com.google.android.apps.photos.content".equals(uri
            .getAuthority());
}

public static String getDataColumn(Context context, Uri uri,
                                   String selection, String[] selectionArgs) {

    Cursor cursor = null;
    final String column = "_data";
    final String[] projection = {column};

    try {
        cursor = context.getContentResolver().query(uri, projection,
                selection, selectionArgs, null);
        if (cursor != null && cursor.moveToFirst()) {
            final int index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(index);
        }
    } finally {
        if (cursor != null)
            cursor.close();
    }
    return null;
}

public static boolean isExternalStorageDocument(Uri uri) {
    return "com.android.externalstorage.documents".equals(uri
            .getAuthority());
}

Answer 4

试试这种方式

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent" android:layout_height="fill_parent"
 android:orientation="vertical">

 <TextView android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="@string/hello" />

 <EditText android:id="@+id/myInputText"
     android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:ems="10" android:lines="5"
  android:minLines="3" android:gravity="top|left"
  android:inputType="textMultiLine">

  <requestFocus />
 </EditText>

 <Button android:id="@+id/saveInternalStorage"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:text="Save to Internal Storage" />

 <Button android:id="@+id/getInternalStorage"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:text="Display from Internal Storage" />

 <Button android:id="@+id/saveExternalStorage"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:text="Save to External Storage" />

 <Button android:id="@+id/getExternalStorage"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:text="Display from External Storage" />

 <TextView android:id="@+id/responseText"
     android:layout_width="wrap_content"
  android:layout_height="wrap_content" android:padding="5dp"
  android:text=""
  android:textAppearance="?android:attr/textAppearanceMedium" />

</LinearLayout>

AndroidStorageActivity.java

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import android.app.Activity;
import android.content.Context;
import android.content.ContextWrapper;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class AndroidStorageActivity extends Activity implements OnClickListener{

 private String filename = "MySampleFile.txt";
 private String filepath = "MyFileStorage";
 File myInternalFile;
 File myExternalFile;
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);

  ContextWrapper contextWrapper = new ContextWrapper(getApplicationContext());
  File directory = contextWrapper.getDir(filepath, Context.MODE_PRIVATE);
  myInternalFile = new File(directory , filename);

  Button saveToInternalStorage = 
   (Button) findViewById(R.id.saveInternalStorage);
  saveToInternalStorage.setOnClickListener(this);

  Button readFromInternalStorage = 
   (Button) findViewById(R.id.getInternalStorage);
  readFromInternalStorage.setOnClickListener(this);

  Button saveToExternalStorage = 
   (Button) findViewById(R.id.saveExternalStorage);
  saveToExternalStorage.setOnClickListener(this);

  Button readFromExternalStorage = 
   (Button) findViewById(R.id.getExternalStorage);
  readFromExternalStorage.setOnClickListener(this);

  //check if external storage is available and not read only  
  if (!isExternalStorageAvailable() || isExternalStorageReadOnly()) {  
   saveToExternalStorage.setEnabled(false);
  } 
  else {
   myExternalFile = new File(getExternalFilesDir(filepath), filename);
  }

 }

 public void onClick(View v) {

  EditText myInputText = (EditText) findViewById(R.id.myInputText);
  TextView responseText = (TextView) findViewById(R.id.responseText);
  String myData = "";

  switch (v.getId()) {
  case R.id.saveInternalStorage:
   try {
    FileOutputStream fos = new FileOutputStream(myInternalFile);
    fos.write(myInputText.getText().toString().getBytes());
    fos.close();
   } catch (IOException e) {
    e.printStackTrace();
   }
   myInputText.setText("");
   responseText
   .setText("MySampleFile.txt saved to Internal Storage...");
   break;

  case R.id.getInternalStorage:
   try {
    FileInputStream fis = new FileInputStream(myInternalFile);
    DataInputStream in = new DataInputStream(fis);
    BufferedReader br = 
     new BufferedReader(new InputStreamReader(in));
    String strLine;
    while ((strLine = br.readLine()) != null) {
     myData = myData + strLine;
    }
    in.close();
   } catch (IOException e) {
    e.printStackTrace();
   }
   myInputText.setText(myData);
   responseText
   .setText("MySampleFile.txt data retrieved from Internal Storage...");
   break;

  case R.id.saveExternalStorage:
   try {
    FileOutputStream fos = new FileOutputStream(myExternalFile);
    fos.write(myInputText.getText().toString().getBytes());
    fos.close();
   } catch (IOException e) {
    e.printStackTrace();
   }
   myInputText.setText("");
   responseText
   .setText("MySampleFile.txt saved to External Storage...");
   break;

  case R.id.getExternalStorage:
   try {
    FileInputStream fis = new FileInputStream(myExternalFile);
    DataInputStream in = new DataInputStream(fis);
    BufferedReader br = 
     new BufferedReader(new InputStreamReader(in));
    String strLine;
    while ((strLine = br.readLine()) != null) {
     myData = myData + strLine;
    }
    in.close();
   } catch (IOException e) {
    e.printStackTrace();
   }
   myInputText.setText(myData);
   responseText
   .setText("MySampleFile.txt data retrieved from Internal Storage...");
   break;


  }
 }

 private static boolean isExternalStorageReadOnly() {  
  String extStorageState = Environment.getExternalStorageState();  
  if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(extStorageState)) {  
   return true;  
  }  
  return false;  
 }  

 private static boolean isExternalStorageAvailable() {  
  String extStorageState = Environment.getExternalStorageState();  
  if (Environment.MEDIA_MOUNTED.equals(extStorageState)) {  
   return true;  
  }  
  return false;  
 }  

}

你会得到像这样的输出

Answer 5

很容易获得内部和外部SD卡路径的路径。 为此，我们只需要使用反射mehtod，而无需生根或签署应用程序。 在清单中添加以下权限。

uses-permission android：name =＆＃34; android.permission.MOUNT_UNMOUNT_FILESYSTEMS＆＃34;

代码：

final class surfaceControlClass = Class.forName（＆＃34; android.os.storage.StorageManager＆＃34;）;

方法method1 = surfaceControlClass.getMethod（＆＃34; getVolumePaths＆＃34;）

method1.setAccessible（真）;

final Object object = context.getSystemService（Context.STORAGE_SERVICE）;

String [] volumes = method1.invoke（object）