Question

嘿家伙有人可以告诉我为什么我不能将此文件保存到外部SD？你能检查我的代码吗？

 public void Download()
  {
      try {
            //this is the file you want to download from the remote server
            String path ="http://mozilla.cdn.leaseweb.com/firefox/releases/4.0.1/win32/en-US/Firefox%20Setup%204.0.1.exe";
            //this is the name of the local file you will create
            String targetFileName;
                boolean eof = false;
            URL u = new URL(path);
            HttpURLConnection c = (HttpURLConnection) u.openConnection();
            c.setRequestMethod("GET");
            c.setDoOutput(true);
            c.connect();

            //String svto = Environment.getExternalStorageState().toString();
            File path1 = Environment.getExternalStoragePublicDirectory(
                    Environment.DIRECTORY_PICTURES);

            path1.mkdirs();
            FileOutputStream f = new FileOutputStream(new File(path1+"/fox.exe"));
                InputStream in = c.getInputStream();
                byte[] buffer = new byte[1024];
                int len1 = 0;
                while ( (len1 = in.read(buffer)) !=  -1 ) {
                f.write(buffer,0, len1);
                         }
            f.close();
            } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            } catch (ProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

  }

Answer 1

如果您在AndroidManifest.xml文件中没有以下权限，则此操作将失败：

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.INTERNET" />

确保将它们放在顶级<manifest>标记中，而不是指定活动的<application>标记。

Answer 2

我之前遇到过类似的问题。事实证明，在调用Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);

之类的代码之前，我必须先在SD卡上手动创建目录。

检查文件资源管理器中是否存在该目录的绝对路径。如果没有，则通过adb shell创建，然后再试一次。这解决了我的问题，但它可能不一定能解决你的问题，试试吧！

Android保存到外部SD卡？

2 个答案: