android - 打开保存在android中临时文件夹中的pdf

Question

我在一个 Android 应用程序中工作，我想将我的 PDF 保存在一个临时文件夹中，我成功保存了它。但是我无法检索 PDF 并在 adobe reader 中查看它。它说“找不到文件或文件夹”。

请查看我的代码。

    private final String TEMP_FILE_NAME = "wpta_temp_file1.pdf";
    private File tempFile=null;


    //Method to download the pdf and save to temp folder
    public void downloadHTTP(String imageURL) {

            DefaultHttpClient httpclient = new DefaultHttpClient();
            try {

                long startTime = System.currentTimeMillis();
                httpclient.getCredentialsProvider().setCredentials(
                        new AuthScope(null, -1),
                        new UsernamePasswordCredentials("username",
                                "password"));

                HttpGet httpget = new HttpGet(imageURL);

                System.out.println("executing request" + httpget.getRequestLine());
                HttpResponse response = httpclient.execute(httpget);
                HttpEntity entity = response.getEntity();

                if (entity != null) {

                    InputStream is = entity.getContent();
                    BufferedInputStream bis = new BufferedInputStream(is);

                    ByteArrayBuffer baf = new ByteArrayBuffer(50);
                    int current = 0;
                    while ((current = bis.read()) != -1) {
                        baf.append((byte) current);
                    }

                    /** Getting Cache Directory */
                    //File cDir = getBaseContext().getCacheDir();
                       File cDir= getExternalFilesDir(null);

                    /** Getting a reference to temporary file, if created earlier */
                    tempFile = new File(cDir.getPath() + "/" + TEMP_FILE_NAME);

                    FileOutputStream fos = new FileOutputStream(tempFile);
                    fos.write(baf.toByteArray());
                    fos.close();
                    Log.d("ImageManager",
                            "download ready in"
                                    + ((System.currentTimeMillis() - startTime) / 1000)
                                    + " sec");
                }

                // EntityUtils.consume(entity);
            } catch (IOException e) {
                Log.d("ImageManager", "Error: " + e);

            } finally {
                // When HttpClient instance is no longer needed,
                // shut down the connection manager to ensure
                // immediate deallocation of all system resources
                httpclient.getConnectionManager().shutdown();
            }
        }

        //Open the pdf saved in the temp folder
        public void showPdf() {

                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setDataAndType(Uri.fromFile(tempFile), "application/pdf");
                intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
                startActivity(intent);

            } catch (Exception e) {
                // No application to view, ask to download one
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setTitle("No Application Found");
                builder.setMessage("Download one from Android Market?");
                builder.setPositiveButton("Yes, Please",
                        new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Intent marketIntent = new Intent(Intent.ACTION_VIEW);
                                marketIntent.setData(Uri
                                        .parse("market://details?id=com.adobe.reader"));
                                startActivity(marketIntent);
                            }
                        });
                builder.setNegativeButton("No, Thanks", null);
                builder.create().show();
            }
        }

Answer 1

getCachedir() 为您的应用提供一个私有(private)目录。其他应用程序无权访问。最好使用 getExternalFilesDir()。