SongList Code in the imageNot able to understand what actually the error is and why it is caused.Error shown shown below.
图像中的SongList代码无法理解错误实际是什么以及导致错误的原因。错误如下所示。
W/System.err: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
W/System.err: at android.os.Handler.<init>(Handler.java:200)
W/System.err: at android.os.Handler.<init>(Handler.java:114)
W/System.err: at android.app.Activity.<init>(Activity.java:754)
W/System.err: at android.app.ListActivity.<init>(ListActivity.java:175)
W/System.err: at com.example.vipul.finalproject.PlayListActivity.<init>(PlayListActivity.java:0)
W/System.err: at com.example.vipul.finalproject.SongList.scanSongs(SongList.java:296)
W/System.err: at com.example.vipul.finalproject.activities.ActivityMenuMain$ScanSongs.doInBackground(ActivityMenuMain.java:299)
W/System.err: at com.example.vipul.finalproject.activities.ActivityMenuMain$ScanSongs.doInBackground(ActivityMenuMain.java:289)
W/System.err: at android.os.AsyncTask$2.call(AsyncTask.java:295)
W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
W/System.err: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
W/System.err: at java.lang.Thread.run(Thread.java:818)
2 个解决方案
#1
-1
The best explanation on why you need a looper on one thread to save instructions and another thread to execute them. In a multi thread application task may come while executing other task.
最好的解释为什么你需要一个线程上的looper来保存指令和另一个线程来执行它们。在多线程应用程序中,任务可能在执行其他任务时出现。
#2
2
See this article to understand the whole Looper/Handler relationship.
请参阅此文章以了解整个Looper / Handler关系。
Long story short, your Thread#run() method must follow a structure like so:
简而言之,你的Thread#run()方法必须遵循这样的结构:
new Thread(new Runnable() {
@Override
public void run() {
Looper.prepare();
mHandler = new Handler();
Looper.loop();
}
}).start();
#1
-1
The best explanation on why you need a looper on one thread to save instructions and another thread to execute them. In a multi thread application task may come while executing other task.
最好的解释为什么你需要一个线程上的looper来保存指令和另一个线程来执行它们。在多线程应用程序中,任务可能在执行其他任务时出现。
#2
2
See this article to understand the whole Looper/Handler relationship.
请参阅此文章以了解整个Looper / Handler关系。
Long story short, your Thread#run() method must follow a structure like so:
简而言之,你的Thread#run()方法必须遵循这样的结构:
new Thread(new Runnable() {
@Override
public void run() {
Looper.prepare();
mHandler = new Handler();
Looper.loop();
}
}).start();