相关疑难解决方法(0)

在Lollipop中,下载功能在我的应用程序中运行良好,但是当我升级到Marshmallow时,我的应用程序崩溃并在我尝试从互联网下载到SD卡时出现此错误:

Neither user  nor current process has android.permission.WRITE_EXTERNAL_STORAGE

它抱怨这行代码:

DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
manager.enqueue(request);

我在应用程序外的清单中拥有权限:

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

我清理并重建了项目,但它仍然崩溃.

如何从Android中的给定网址下载并保存图像？

我想将图像从URL保存到SD卡(以备将来使用),然后从SD卡加载该图像,将其用作Google地图的可绘制叠加层.

这是函数的保存部分:

//SAVE TO FILE

String filepath = Environment.getExternalStorageDirectory().getAbsolutePath(); 
String extraPath = "/Map-"+RowNumber+"-"+ColNumber+".png";
filepath += extraPath;

FileOutputStream fos = null;
fos = new FileOutputStream(filepath); 

bmImg.compress(CompressFormat.PNG, 75, fos);

//LOAD IMAGE FROM FILE
Drawable d = Drawable.createFromPath(filepath);
return d;

图像以succuessfully的形式保存到SD卡,但在到达createFromPath()线路时失败.我不明白为什么它会保存到那个目的地但不加载它....

我正在制作使用DownloadManager的Android应用程序.我想将文件下载到我制作的文件夹中.但是这些来源不起作用.并发生IllegalstateException.我能做什么？？

urlToDownload = Uri.parse(URL);
List<String> pathSegments = urlToDownload.getPathSegments();
request = new DownloadManager.Request(urlToDownload);
request.setTitle(Titlename);
request.setDescription("MCPE STORE");
request.setDestinationInExternalPublicDir(
                   Environment.getExternalStorageDirectory().getAbsolutePath() + 
                   "/MCPE STORE", pathSegments.get(pathSegments.size()-1));

Environment.getExternalStoragePublicDirectory(
                   Environment.getExternalStorageDirectory().getAbsolutePath() + 
                   "/MCPE STORE").mkdir();
latestId = downloadManager.enqueue(request);

我得到了这个例外:

10-24 17:08:19.711: E/AndroidRuntime(1379): FATAL EXCEPTION: main
10-24 17:08:19.711: E/AndroidRuntime(1379): java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.campusfqm.cfqm/br.com.campusfqm.cfqm.DownloadManagerActivity}: java.lang.IllegalStateException: Unable to create directory: /mnt/sdcard/Download
10-24 17:08:19.711: E/AndroidRuntime(1379):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1736)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1752)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at android.app.ActivityThread.access$1500(ActivityThread.java:123)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:993)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at android.os.Handler.dispatchMessage(Handler.java:99)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at android.os.Looper.loop(Looper.java:126)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at android.app.ActivityThread.main(ActivityThread.java:3997)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at java.lang.reflect.Method.invokeNative(Native Method)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at java.lang.reflect.Method.invoke(Method.java:491)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
10-24 17:08:19.711: E/AndroidRuntime(1379):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
10-24 17:08:19.711: …

我在我的应用程序中面临两个问题.

1-我正在使用Android DownloadManager下载在线文件,但它将所有文件下载到系统Download目录,使用说明目录

request.setDestinationInExternalPublicDir(Environment.DIRECTORY_PICTURES, "fileName");

现在我想将文件下载到我自己的目录中说"新建文件夹".如何实施呢？请在这方面帮助我,我会非常感激.

2-如何检查SD卡是否可用？

我想在我的代码中使用按钮保存URL中的图像我已经创建了目标文件夹,但我尝试了各种代码来保存图片但是什么都不起作用:

public class B_X extends Activity {   
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.bx);

        Button buttonSetWallpaper = (Button)findViewById(R.id.bSetWall);
        buttonSetWallpaper.setOnClickListener(new Button.OnClickListener(){

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                File folder = new File(Environment.getExternalStorageDirectory() + "/PerfectAss/");
                boolean success = false;
                if (!folder.exists()) {
                    success = folder.mkdirs();
                }

                if (!success) {
            } else {
            }

                 Toast.makeText(getApplicationContext(), "The image has been saved", Toast.LENGTH_LONG).show();
                    URL url = new URL ("http://bitsparrow.altervista.org/wp-content/uploads/2013/04/5.jpg");
                    InputStream input = url.openStream();
                     try …

我正在使用 Android 从服务器下载视频DownloadManager。我想自己给每个视频起一个名字。默认情况下视频的名称为 downloadfile-6.bin。

String servicestring = Context.DOWNLOAD_SERVICE;
DownloadManager downloadmanager;
downloadmanager = (DownloadManager) getSystemService(servicestring);
Uri uri = Uri.parse(links.get(0));
DownloadManager.Request request = new DownloadManager.Request(uri);
Long reference = downloadmanager.enqueue(request);

建议将不胜感激。