如何使 UI 即使点击加载按钮也能响应

Question

任何人都可以帮助我如何使列表视图即使单击加载也能响应 button.I 我正在尝试使用下面的代码，但是在加载过程中它崩溃了，如果我尝试单击列表视图应用程序崩溃了。

protected void onPreExecute() {

        super.onPreExecute();




        new Thread() {
            public void run() {
                while (i++ < 1000) {

                    try {
                        runOnUiThread(new Runnable() {


                            @Override
                            public void run() {

                                imgvw.setOnClickListener(new OnClickListener() {

                                    @Override
                                    public void onClick(View v) {
                                        // TODO Auto-generated method stub
                                        // new Thread();

                                        v.setVisibility(View.INVISIBLE);
                                        View progressBar12 = findViewById(R.id.progressBar12);
                                        progressBar12.setVisibility(View.VISIBLE);
                                        Toast.makeText(getApplicationContext(), "Background Fetch",0).show();                               
                                        imgvw.refreshDrawableState();
                                        isrefresh = true;
                                        try {
                                            new InqLis();
                                        } catch (Exception e) {
                                            System.out.println("Errors are:"+e);
                                        }



                            }   
                        });
                            }


                        });

                        Thread.sleep(300);

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

                }

                manojAdapter.notifyDataSetChanged();
                manojAdapter.notifyDataSetInvalidated();
            }


        }.start();



    View progressBar12 = findViewById(R.id.progressBar12);
       progressBar12.setVisibility(View.GONE);
        imgvw.setVisibility(View.VISIBLE);



    }

02-18 21:17:33.382: E/InputEventReceiver(26835): Exception dispatching input event.
02-18 21:17:33.383: E/MessageQueue-JNI(26835): Exception in MessageQueue callback: handleReceiveCallback
02-18 21:17:33.436: E/MessageQueue-JNI(26835): java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. Make sure your adapter calls notifyDataSetChanged() when its content changes. [in ListView(16908298, class com.handmark.pulltorefresh.library.PullToRefreshExpandableListView$InternalExpandableListViewSDK9) with Adapter(class android.widget.ExpandableListConnector)]
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.widget.ListView.layoutChildren(ListView.java:1555)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.widget.AbsListView.onTouchUp(AbsListView.java:3617)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.widget.AbsListView.onTouchEvent(AbsListView.java:3429)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.View.dispatchTouchEvent(View.java:7736)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2212)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1945)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2218)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2068)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1515)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.app.Activity.dispatchTouchEvent(Activity.java:2466)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2016)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.View.dispatchPointerEvent(View.java:7916)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4030)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3909)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3459)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3509)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3478)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3585)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3486)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3642)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3459)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3509)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3478)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3486)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3459)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5727)
02-18 21:17:33.436: E/MessageQueue-JNI(26835):  at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:56

Answer 1

首先，您似乎正在使用 asyncTask。

我会查看 android 开发人员文档以正确使用：AsyncTask

一个asyctask有3个主要部分：

onPreExecute- 在 UI 线程上运行
doInBackground- 在后台线程上运行
onPostExecute- 在 UI 线程上运行

所以：在 onPreExecute 中显示加载对话框在 doInBackground 做你的主要工作在 onPostExecute 中隐藏加载对话框并用结果

更新你的 UI

此过程将为您提供响应迅速且线程安全的解决方案。（并且您不必使用可运行或睡眠线程）

其次：

你的错误是： The content of the adapter has changed but ListView did not receive a notification.

这很可能是由于线程休眠时间过长造成的。这会导致在未调用 notifyDataSetChanged() 的情况下更改适配器的内容。

结论：最可靠的解决方案是使用 AsyncTask 的 doInBackground 方法进行后台工作。

下面是一个正确使用 AsyncTask 的例子：

    private static class ExampleAsync extends AsyncTask<Void, Void, ArrayList<ExampleObject>> {
    private GenericRecycler adapter;

    public ExampleAsync(GenericRecycler theAdapter){
        this.adapter = theAdapter;
    } 

    @Override //runs on main UI Thread
    protected void onPreExecute() {
        super.onPreExecute();
        //make any UI changes here to display while loading
    }



    // runs in a seperate thread
    @Override
    protected ArrayList<ExampleObject> doInBackground(Void... params) {

        ArrayList<ExampleObject> exampleList = new ArrayList<ExampleObject>(10);

        //waiting instead of doing work
        //this is where you should do an http request and create a list of data
        synchronized (this){
            try {
                wait(10000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        return exampleList;
    }

    //this runs on main ui thread
    @Override
    protected void onPostExecute(ArrayList<ExampleObject> objects){

        adapter.setData(objects);

        //any time that data in adapter is changed, notifydatasetchanged() must be called
        adapter.notifyDataSetChanged();

    }
}

如何使 UI 即使点击加载按钮也能响应

How to make UI responsive even clicking loading button

android

json

android-listview