Question

我从我的android日志中收到此错误，我已经查看了其他有这种问题的线程，但我仍然无法修复自己的问题

基本上，我想通过回调机制

从服务类更新我的UI

//this method is inside the fragment class
public void updateProgress(int progress){
    switch(progress){
        case Constants.ProgressUIPostUser.PD_VALIDATE_USER:
            pdPostUserLoading = ProgressDialog.show(getActivity(), "Registration", "Validating user...", true, false);
            break;
        case Constants.ProgressUIPostUser.PD_POSTING_DATA:
            pdPostUserLoading = ProgressDialog.show(getActivity(), "Registration", "Posting data...", true, false);
            break;
        case Constants.ProgressUIPostUser.PD_OPEN_CONNECTION:
            pdPostUserLoading = ProgressDialog.show(getActivity(), "Registration", "Open connection...", true, false);
            break;
        case Constants.ProgressUIPostUser.PD_OBTAINING_RESPONSE:
            pdPostUserLoading = ProgressDialog.show(getActivity(), "Registration", "Obtaining Response...", true, false);
            break;
        case Constants.ProgressUIPostUser.PD_DISMISS:
            if(pdPostUserLoading != null)
                pdPostUserLoading.dismiss();
            break;


    }
}

然后我从处理器类（从服务类调用）

调用此语句

callback.updateProgress(Constants.ProgressUIPostUser.PD_OPEN_CONNECTION);

来自服务类

public interface Callback {
    void updateProgress(int progress);
}

class Task implements  Runnable{
    public void run(){
        PostNewUserProcessor processor  = new PostNewUserProcessor(mCallback);
        boolean valid = processor.postUser(newUser);

        if(valid){
            //Todo
        }
        else{
            //TODO
        }
    }

public void postUser(Bundle data){

        //Retrieve data from the intent
    newUser = data.getParcelable(Constants.NEW_USER);

    new Thread(new Task());
}

记录错误

07-18 18:52:44.994    8942-9612/? E/AndroidRuntime﹕ FATAL EXCEPTION: Thread-1137
    java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
            at android.os.Handler.<init>(Handler.java:197)
            at android.os.Handler.<init>(Handler.java:111)
            at android.app.Dialog.<init>(Dialog.java:108)
            at android.app.AlertDialog.<init>(AlertDialog.java:114)
            at android.app.AlertDialog.<init>(AlertDialog.java:98)
            at android.app.ProgressDialog.<init>(ProgressDialog.java:77)
            at android.app.ProgressDialog.show(ProgressDialog.java:110)
            at android.app.ProgressDialog.show(ProgressDialog.java:104)
            at com.robertlimantoproject.bookreviewapp.activity.RegistrationPageFragment.updateProgress(RegistrationPageFragment.java:354)
            at com.robertlimantoproject.bookreviewapp.processor.PostNewUserProcessor.postUser(PostNewUserProcessor.java:81)
            at com.robertlimantoproject.bookreviewapp.service.PostNewUserService$Task.run(PostNewUserService.java:61)
            at com.robertlimantoproject.bookreviewapp.utils.Util$1.run(Util.java:36)

Answer 1

您正在从非UI线程调用PostNewUserProcessor processor = new PostNewUserProcessor(mCallback);。

但是应该在UI线程中显示一个对话框。喜欢这个..

 case Constants.ProgressUIPostUser.PD_VALIDATE_USER:
           getActivity().runOnUiThread(new Runnable() {

            @Override
            public void run() {
                pdPostUserLoading = ProgressDialog.show(getActivity(), "Registration", "Validating user...", true, false);

            }
        });
            break;

Answer 2

添加

Looper.prepare();

在你的线程内作为第一个语句。

阅读以下内容，了解有关Looper线程的更多信息：

http://www.oracle.com/technetwork/java/javaee/downloads/index.html

Answer 3

如错误所示，您忘记在线程中添加looper.prepare。
看看这里：
Can't create handler inside thread which has not called Looper.prepare()和
Can't create handler inside thread that has not called Looper.prepare() in android。
接下来，为了实现你想要的东西，请看这里：
Can't see ProgressDialog while AsyncTask run in background
教程：
http://www.41post.com/4588/programming/android-coding-a-loading-screen-part-1

无法在线程内创建处理程序 - Android

3 个答案: