android - 如何在 Android 中的 Thread 中使用 toast 消息

Question

当我在 Thread 类的 run 方法中使用 Toast 时，我遇到了一些问题。

我的错误日志

09-16 11:42:38.140: E/AndroidRuntime(1446): in writeCrashedAppName, pkgName :com.monday.worker_android
09-16 11:59:17.920: E/AndroidRuntime(2144): FATAL EXCEPTION: AsyncTask #1
09-16 11:59:17.920: E/AndroidRuntime(2144): java.lang.RuntimeException: An error occured while executing doInBackground()
09-16 11:59:17.920: E/AndroidRuntime(2144):     at android.os.AsyncTask$3.done(AsyncTask.java:200)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at java.util.concurrent.FutureTask.run(FutureTask.java:138)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at java.lang.Thread.run(Thread.java:1019)
09-16 11:59:17.920: E/AndroidRuntime(2144): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
09-16 11:59:17.920: E/AndroidRuntime(2144):     at android.os.Handler.<init>(Handler.java:121)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at android.widget.Toast.<init>(Toast.java:75)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at android.widget.Toast.makeText(Toast.java:244)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at com.monday.worker_android.SwipePage$2.doInBackground(SwipePage.java:142)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at com.monday.worker_android.SwipePage$2.doInBackground(SwipePage.java:1)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at android.os.AsyncTask$2.call(AsyncTask.java:185)
09-16 11:59:17.920: E/AndroidRuntime(2144):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)

但是当我忽略 Toast 时它工作正常。但我想使用它。请帮忙。

Answer 1

通过从您的线程调用 Activity 的 runOnUiThread 方法:

activity.runOnUiThread(new Runnable() {
    public void run() {
        Toast.makeText(activity, "Toast message inside Thread", Toast.LENGTH_LONG).show();
    }
});