java - 当线程完成并调用 dialog.dismiss() 时出现 WindowLeaked 异常；

Question

我有一个选项卡布局应用程序，它需要在启动时立即下载一些文件，因此在我调用 onCreate 方法的 Main.java 文件中:

  myProgressDialog = ProgressDialog.show(Controller.this,
                "Please wait...", "Doing Extreme Calculations...", true);
    downloadFile(NAME_LOCAL, NAME_SERVER, true);

downloadFile 是一个单独的线程，它看起来像这样:

 protected void downloadFile(final String localFilePath, final String remoteFileName, final boolean ASCII) {

            // Fire off a thread to do some work that we shouldn't do directly in the UI thread

            Thread a = new Thread() {
                public void run() {


                    Logger.setLevel(Level.DEBUG); 


                        try{
                            //create client
                            log.info("Creating Client");
                            ftp = new FileTransferClient();
                            log.info("Setting Remote Host");
                            ftp.setRemoteHost(host);
                            ftp.setUserName(username);
                            ftp.setPassword(password);
                            //connect. . .We hope
                            log.info("Connecting to server " + host);
                            ftp.connect();
                            ftp.getAdvancedFTPSettings().setConnectMode(FTPConnectMode.PASV);
                            if(ASCII){
                            ftp.setContentType(FTPTransferType.ASCII);
                            Log.d("ASCII", "USING ASCII");
                            }else if(!ASCII){
                                Log.d("BINARY", "USING BINARY");
                                ftp.setContentType(FTPTransferType.BINARY);

                            }

                            ftp.downloadFile(cache + localFilePath , remoteFileName);

                        }catch (Exception e){
                            e.printStackTrace();

                        }





                    mHandler.post(mUpdateResults);
                    Handler handler=new Handler();
                    handler.post(new Runnable(){public void run(){myProgressDialog.dismiss();}});

                }
            };
            a.start();

        }

在 log cat 中，它开始下载，然后突然完成，它给了我这个:

02-17 17:27:51.175: ERROR/WindowManager(2523): Activity org.IRE.toolbox.Controller has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@46eba2f0 that was originally added here

02-17 17:27:51.175: ERROR/WindowManager(2523): android.view.WindowLeaked: Activity org.IRE.toolbox.Controller has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@46eba2f0 that was originally added here

这是怎么回事？!提前致谢!

Answer 1

发布的代码将在 Thread.run() 中引发异常:

Handler handler=new Handler();

原因是线程还没有调用Looper.prepare。您可能会看到“强制关闭”提示，如果您深入了解日志，您可能会发现类似以下内容:

ERROR/AndroidRuntime(1161): Uncaught handler: thread Thread-9 exiting due to uncaught exception
ERROR/AndroidRuntime(1161): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
ERROR/AndroidRuntime(1161):     at android.os.Handler.<init>(Handler.java:121)