Question

我正在尝试从服务器下载pdf并按原样显示它。

我尝试了以下代码段，但它给了我错误，如下所示。

我无法理解为什么它会给No Activity found to handle Intent例外。

我是android新手，所以任何帮助都赞赏...

onCreate（）摘录

String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
    File folder = new File(extStorageDirectory, "pdf");
    folder.mkdir();
    File file = new File(folder, "Read.pdf");
    try {
        file.createNewFile();
    } catch (IOException e1) {
        e1.printStackTrace();
    }
    Downloader.DownloadFile(
            "http://www.nmu.ac.in/ejournals/aspx/courselist.pdf", file);

    File file1 = new File(Environment.getExternalStorageDirectory()
            + "/pdf/Read.pdf");
    PackageManager packageManager = getPackageManager();
    Intent testIntent = new Intent(Intent.ACTION_VIEW);
    testIntent.setType("application/pdf");
    @SuppressWarnings({ "rawtypes", "unused" })
    List list = packageManager.queryIntentActivities(testIntent,
            PackageManager.MATCH_DEFAULT_ONLY);
    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_VIEW);
    Uri uri = Uri.fromFile(file1);
    intent.setDataAndType(uri, "application/pdf");
    startActivity(intent);

logcat的

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.pdftest/com.pdftest.PDFFromServerExample}: No Activity found to handle Intent { act=android.intent.action.VIEW dat=file:///mnt/sdcard/pdf/Read.pdf typ=application/pdf }
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
at android.app.ActivityThread.access$2300(ActivityThread.java:125)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.VIEW dat=file:///mnt/sdcard/pdf/Read.pdf typ=application/pdf }
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1408)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
at android.app.Activity.startActivityForResult(Activity.java:2817)
at android.app.Activity.startActivity(Activity.java:2923)
at com.pdftest.PDFFromServerExample.onCreate(PDFFromServerExample.java:44)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)

Answer 1

默认情况下，没有可以处理显示pdf的应用程序，这通常是第三方应用程序。具体而言，您感兴趣的是意图的动作以及如何捕获它并在可能的情况下显示它。

Answer 2

Android不会提供任何读取PDF内容的内置应用程序。所以，在你的情况下，你正在做

typ=application/pdf

但是没有应用程序可以读取或知道这指的是什么。因此，您必须安装PDF阅读器，我可以尝试链接typ=application/pdf并将其传递给该应用程序以阅读PDF。

Answer 3

虽然您尝试阅读pdf，但似乎没有 pdf阅读器。

你唯一需要做的就是安装pdf阅读器，如adobe reader或其他一些东西。这个代码在那之后会正常工作!!!!

你的目的只是查看pdf并且你有互联网连接然后在谷歌文档中打开你的pdf就好了，比如

http://docs.google.com/viewer?url=http://www.nmu.ac.in/ejournals/aspx/courselist.pdf

注意:(嗯..这是查看pdf的替代方法，老实说我不推荐它）

Answer 4

Uri path = Uri.fromFile(dwonload_file_name);
                try {
                    Intent intent = new Intent(Intent.ACTION_VIEW);
                    intent.setDataAndType(path, "application/pdf");
                    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(intent);
                    finish();
                } catch (ActivityNotFoundException e) {
                    Toast.makeText(
                            context,
                            "PDF Reader application is not installed in your device",
                            Toast.LENGTH_SHORT).show();

                }

希望它会有所帮助。 Full Source Code for "How to download file from Server"

从服务器下载pdf并显示它

4 个答案: