Android 对5.0+的外置SD卡删除操作

来源：互联网发布：安卓助手for mac 编辑：程序博客网时间：2024/06/05 19:31

#在4.4以上中，谷歌对其已经做了权限限制，为了规范SD卡操作!在推出后，引起业界一片吐槽，迫于压力，google推出了一种全新的方式去操作SD卡:Android SAF

注:
一定要进行版本判断
一定要进行版本判断
一定要进行版本判断

private static int DOCUMENT_TREE_REQUEST = 1; Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE); activity.startActivityForResult(intent, DOCUMENT_TREE_REQUEST);

通过上面意图会进入到:
http://jingyan.baidu.com/article/91f5db1b3fc3981c7f05e3f1.html(这时es文件管理器的操作方式，其实都一样)

选择SD卡后,会调用

public static String ACTION_OPEN_DOCUMENT_TREE_URL = "ACTION_OPEN_DOCUMENT_TREE";    @TargetApi(Build.VERSION_CODES.KITKAT)    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        SharedPreferences lee = getApplicationContext().getSharedPreferences("xxx", 0);        if (requestCode == 1) {                String p = lee.getString("URI", null);                Uri oldUri = null;                if (p != null) oldUri = Uri.parse(p);                Uri treeUri = null;                if (resultCode == Activity.RESULT_OK) {                    // Get Uri from Storage Access Framework.                    treeUri = data.getData();                    // Persist URI - this is required for verification of writability.                    if (treeUri != null) lee.edit().putString(ACTION_OPEN_DOCUMENT_TREE_URL, treeUri.toString()).commit();                }                // If not confirmed SAF, or if still not writable, then revert settings.                if (resultCode != Activity.RESULT_OK) {               /* DialogUtil.displayError(getActivity(), R.string.message_dialog_cannot_write_to_folder_saf, false,                        currentFolder);||!FileUtil.isWritableNormalOrSaf(currentFolder)*/                    if (treeUri != null) lee.edit().putString(ACTION_OPEN_DOCUMENT_TREE_URL, oldUri.toString()).commit();                    return;                }                // After confirmation, update stored value of folder.                // Persist access permissions.                final int takeFlags = data.getFlags()                        & (Intent.FLAG_GRANT_READ_URI_PERMISSION                        | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);                getContentResolver().takePersistableUriPermission(treeUri, takeFlags);                Toast.makeText(getApplicationContext(),getApplicationContext().getString(R.string.success_get_premiss_tips),Toast.LENGTH_SHORT).show();        }    }

注意上面的 SharedPreferences lee = getApplicationContext().getSharedPreferences(“xxx”, 0); 会将URI保存到SharedPreferences中，
然后在需要删除外置SD卡时我们需要获取一个DocumentFile对象

  public  DocumentFile getDocumentFile(final File file, final boolean isDirectory,Context context) {        String baseFolder = getExtSdCardFolder(file,context);        boolean originalDirectory=false;        if (baseFolder == null) {            return null;        }        String relativePath = null;        try {            String fullPath = file.getCanonicalPath();            if(!baseFolder.equals(fullPath))                relativePath = fullPath.substring(baseFolder.length() + 1);            else originalDirectory=true;        }        catch (IOException e) {            return null;        }        catch (Exception f){            originalDirectory=true;            //continue        }        //此处更换你的SharedPreferences        SharedPreferences lee = context.getSharedPreferences("xxx", 0);        String uri = lee.getString(ACTION_OPEN_DOCUMENT_TREE_URL,null);        Uri parse = Uri.parse(uri);        // start with root of SD card and then parse through document tree.        DocumentFile document = DocumentFile.fromTreeUri(context, parse);        if(originalDirectory)return document;        String[] parts = relativePath.split("\\/");        for (int i = 0; i < parts.length; i++) {            DocumentFile nextDocument = document.findFile(parts[i]);            if (nextDocument == null) {                if ((i < parts.length - 1) || isDirectory) {                    if( document.createDirectory(parts[i])==null){                        return null;                    }                    nextDocument = document.createDirectory(parts[i]);                }                else {                    nextDocument = document.createFile("image", parts[i]);                }            }            document = nextDocument;        }        return document;    } @TargetApi(Build.VERSION_CODES.KITKAT)    public static String getExtSdCardFolder(final File file,Context context) {        String[] extSdPaths = getExtSdCardPaths(context);        try {            for (int i = 0; i < extSdPaths.length; i++) {                if (file.getCanonicalPath().startsWith(extSdPaths[i])) {                    return extSdPaths[i];                }            }        }        catch (IOException e) {            return null;        }        return null;    }    @TargetApi(Build.VERSION_CODES.KITKAT)    public static String[] getExtSdCardPaths(Context context) {        List<String> paths = new ArrayList<String>();        for (File file : context.getExternalFilesDirs("external")) {            if (file != null && !file.equals(context.getExternalFilesDir("external"))) {                int index = file.getAbsolutePath().lastIndexOf("/Android/data");                if (index < 0) {                    Log.w("AmazeFileUtils", "Unexpected external file dir: " + file.getAbsolutePath());                }                else {                    String path = file.getAbsolutePath().substring(0, index);                    try {                        path = new File(path).getCanonicalPath();                    }                    catch (IOException e) {                        // Keep non-canonical path.                    }                    paths.add(path);                }            }        }        if(paths.isEmpty())paths.add("/storage/sdcard1");        return paths.toArray(new String[0]);    }

拿到DocumentFile对象后进行删除操作:

@TargetApi(Build.VERSION_CODES.LOLLIPOP)    public boolean delect(FileInfo f) {        DocumentFile documentFile = getDocumentFile(new File(f.filePath), f.IsDir, mContext);        if(documentFile!=null) {            documentFile.delete();        }else {            //当更换SD卡后，uri值会发生变化，拿到的DocumentFile会为null，而此处在进行一次上面操作既可        }        return true;    }

剩下的创建复制剪贴和File一样，只将换成documentFile既可!

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