意图过滤器类别android.intent.category.default未找到默认活动

Question

         <application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@android:style/Theme.Wallpaper.NoTitleBar.Fullscreen">
    <activity android:name=".MainActivity"
        android:launchMode="singleTask"
        android:stateNotNeeded="true">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.HOME" />
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </activity>
    <activity android:name=".AppListActivity"/>
</application>

这里android.category.default用于将此应用程序作为默认启动器，如谷歌启动器，但在运行此应用程序时，其投掷错误默认活动未找到...我已尝试重新启动并使缓存无效多次。谁能帮我...？

Answer 1

转到“编辑配置”。在“常规”选项卡中，在启动选项下拉列表中，不选择任何内容。现在运行应用程序。

您可以在Windows上使用Control + Shift + A或在Mac上使用Command + Shift + A，然后输入编辑配置以将其打开。

Answer 2

你可以使用它，

package file;

import java.awt.RenderingHints.Key;
import java.io.IOException;
import java.net.URI;
import java.nio.file.FileSystems;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.LinkOption;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.HashMap;
import java.util.Map;



public class file implements Runnable
{
    Path path;
    public void run()
    {
        try(WatchService svc = FileSystems.getDefault().newWatchService()) 
        {
            System.out.println("1");
            Map<WatchKey, Path> keyMap = new HashMap<>();
            System.out.println("2");
            path = Paths.get("C:/test/edit/");
            System.out.println("3");
            file.registerAll(path,svc,keyMap);
            System.out.println("4");
            WatchKey wk = null ;
           while(!Thread.currentThread().isInterrupted())
           {
            do
            {

               try 
                {

                   System.out.println("5");
                    wk = svc.take();
                //  path = keyMap.get(wk.watchable());
                     for(WatchEvent<?> event : wk.pollEvents())
                     {
                         System.out.println("6");
                         WatchEvent.Kind<?> type = event.kind();
                         System.out.println("7");
                         path = (Path) wk.watchable();
                    //   Path object = (Path) event.context();
                    //   System.out.println(object.toAbsolutePath());
                         System.out.println("8");
                         Path child = path.resolve((Path)event.context());
                         System.out.println(child);
                         System.out.println("9");
                         URI fullPath = child.toAbsolutePath().toUri();
                         System.out.println("10");
                         System.out.println(fullPath);
                         Path newFilePath = Paths.get(fullPath);
                           if (Files.isDirectory(newFilePath, LinkOption.NOFOLLOW_LINKS))
                            {
                               System.out.println("11");
                                if(type == StandardWatchEventKinds.ENTRY_CREATE)
                                {
                                    System.out.println("12");
                                    register(newFilePath,keyMap,svc);
                                 //   URI uri = child.toUri();
                                  //  path = Paths.get(uri);
                                }

                             System.out.println("\nThe new folder :"+newFilePath+ "Event :" +type);  
                            }
                           else
                           {
                            System.out.println("\nThe new file :"+child+ "Event :" +type);  
                           }
                     }
                } 
               catch (InterruptedException e) 

                {
                    e.printStackTrace();
                }



            }while(wk.reset());

           }
        } 
        catch (IOException e) 
        {

            e.printStackTrace();
        }
    }
    private static Path register(Path newFilePath, Map<WatchKey, Path> keyMap, WatchService svc) throws IOException 
    {
        System.out.println("a");
        Files.walkFileTree(newFilePath.toAbsolutePath(),new SimpleFileVisitor<Path>()
        {

           public FileVisitResult preVisitDirectory(Path newfilePath, BasicFileAttributes attrs) throws IOException
           {
               System.out.println("b");
               if(attrs.isDirectory())
               {
                   System.out.println("c");
                   keyMap.put(newFilePath.register(svc, StandardWatchEventKinds.ENTRY_CREATE),newFilePath);
                   System.out.println("file path in register method : "+newFilePath);
               }
               System.out.println("d");
               return FileVisitResult.CONTINUE;
           }
        });

return newFilePath;

    }
    private static Path registerAll(Path path,  WatchService svc,Map<WatchKey, Path> keyMap) 
    {

         try {
            Files.walkFileTree(path.toAbsolutePath(),new SimpleFileVisitor<Path>()
                     {

                        public FileVisitResult preVisitDirectory(Path path, BasicFileAttributes attrs) throws IOException
                        {
                            System.out.println("aa");
                            if(attrs.isDirectory())
                            {
                                System.out.println("bb");
                                keyMap.put(path.register(svc, StandardWatchEventKinds.ENTRY_CREATE),path);
                                System.out.println("file path in registerAll method : "+path);
                            }
                            System.out.println("cc");
                            return FileVisitResult.CONTINUE;
                        }
                     });
        } 
        catch (IOException e)
        {
            e.printStackTrace();
        }

      return path;
    }
    public static void main(String args [])
    {
        file f = new file();
        Thread t = new Thread(f);
        t.start();
    }
}

Answer 3

只需在android studio中指定午餐活动即可。为此，请点击run configuration - ＆gt; Edit configurations。

在Launch Options选择Specified Activity，然后选择您的活动。