Question

更新：I created a repository代码更少，使其更容易理解。

我正在尝试创建一个小部件。我按照这里描述的那样做了：https://stackoverflow.com/a/6093753/2180161

部分工作，但我有一个非常奇怪的错误。我做了一个截屏视频，所以更容易理解我的意思： http://c.maysi.de/c6H9

截图：

正如您所看到的，有一些项目是随机添加的。（RemoteViews已添加到另一个RemoteViews对象中） 当我调整小部件的大小时也会发生同样的情况。

我在日志中打印的内容与预期的一样。没有错误的数据。滚动时也没有新的日志条目。

这是我的代码：

RemoteViewsFactory：

@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public class MyWidgetViewsFactory implements RemoteViewsService.RemoteViewsFactory {
    private static ArrayList<Item> items = new ArrayList<>();
    private static int itemnr = 0;
    private static int subitemnr = 0;
    private int appWidgetId;
    private Context context;

    public MyWidgetViewsFactory(Context context, Intent intent) {
        this.context = context;
        appWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,
                AppWidgetManager.INVALID_APPWIDGET_ID);


        //Some random data to display
        for (int i = 0; i < 10; i++) {
            Item item = new Item(String.valueOf(itemnr++));

            for (int j = 0; j < 3; j++) {
                String[] subitem = {String.valueOf(subitemnr++), String.valueOf(subitemnr++), String.valueOf(subitemnr++)};
                item.addSubitem(subitem);
            }

            items.add(item);
        }
    }

    @Override
    public void onCreate() {
        // no-op
    }

    @Override
    public void onDestroy() {
        // no-op
    }

    @Override
    public int getCount() {
        return items.size();
    }

    @Override
    public RemoteViews getViewAt(int position) {
        Log.d("MyWidgetViewsFactory", "getViewAt(" + position + "):" + items.get(position));
        Item item = items.get(position);

        RemoteViews itemView = new RemoteViews(context.getPackageName(), R.layout.widget_listview_item);

        itemView.setTextViewText(R.id.textView_itemnr, item.getItemNr());

        for (String[] s : item.getSubitems()) {
            Log.d("MyWidgetViewsFactory", "subitem:" + s[0] + "|" + s[1] + "|" + s[2]);
            RemoteViews subitem = new RemoteViews(context.getPackageName(), R.layout.widget_listview_subitem);

            subitem.setTextViewText(R.id.textView_1, s[0]);
            subitem.setTextViewText(R.id.textView_2, s[1]);
            subitem.setTextViewText(R.id.textView_3, s[2]);

            itemView.addView(R.id.linearLayout_item_body, subitem);
        }
        return itemView;
    }

    @Override
    public RemoteViews getLoadingView() {
        return (null);
    }

    @Override
    public int getViewTypeCount() {
        return (1);
    }

    @Override
    public long getItemId(int position) {
        return (position);
    }

    @Override
    public boolean hasStableIds() {
        return (true);
    }

    @Override
    public void onDataSetChanged() {
        // no-op
    }

    class Item {
        private ArrayList<String[]> subitems = new ArrayList<>();
        private String itemnr = "";

        Item(String itemnr) {
            this.itemnr = itemnr;
        }

        Item() {
        }

        public void addSubitem(String[] subitem) {
            this.subitems.add(subitem);
        }

        public ArrayList<String[]> getSubitems() {
            return subitems;
        }

        public String getItemNr() {
            return itemnr;
        }

        public void setItemNr(String itemnr) {
            this.itemnr = itemnr;
        }
    }
}

的AppWidgetProvider

    public class MyWidgetProvider extends AppWidgetProvider {

    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        // There may be multiple widgets active, so update all of them
        Log.d("MyWidgetProvider", "appWidgetIds.lenght:" + appWidgetIds.length);
        for (int appWidgetId : appWidgetIds) {
            Intent svcIntent = new Intent(context, MyWidgetService.class);
            svcIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);

            RemoteViews widget = new RemoteViews(context.getPackageName(), R.layout.widget_root);

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH)
                widget.setRemoteAdapter(R.id.listView_widget, svcIntent);
            else
                widget.setRemoteAdapter(appWidgetId, R.id.listView_widget, svcIntent);

            /*
            Intent clickIntent = new Intent(context, MainActivity.class);
            PendingIntent clickPI = PendingIntent.getActivity(context, 0, clickIntent, PendingIntent.FLAG_UPDATE_CURRENT);
            widget.setPendingIntentTemplate(R.id.listView_widget, clickPI);*/

            appWidgetManager.updateAppWidget(appWidgetId, widget);
        }
    }

    @Override
    public void onEnabled(Context context) {
        // Enter relevant functionality for when the first widget is created
    }

    @Override
    public void onDisabled(Context context) {
        // Enter relevant functionality for when the last widget is disabled
    }
}

RemoteViewsService

@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public class MyWidgetService extends RemoteViewsService {
    @Override
    public RemoteViewsFactory onGetViewFactory(Intent intent) {
        return (new MyWidgetViewsFactory(this.getApplicationContext(), intent));
    }
}

所有其他资源 can you find in the repo at GitHub.

Logcat输出：

08-08 02:11:10.858  32427-32444/? D/MyWidgetViewsFactory﹕ getViewAt(0):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@3e7179c9
08-08 02:11:10.860  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:0|1|2
08-08 02:11:10.864  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:3|4|5
08-08 02:11:10.866  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:6|7|8
08-08 02:11:10.927  32427-32443/? D/MyWidgetViewsFactory﹕ getViewAt(0):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@3e7179c9
08-08 02:11:10.927  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:0|1|2
08-08 02:11:10.927  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:3|4|5
08-08 02:11:10.927  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:6|7|8
08-08 02:11:10.931  32427-32443/? D/MyWidgetViewsFactory﹕ getViewAt(1):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@23e248ce
08-08 02:11:10.931  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:9|10|11
08-08 02:11:10.931  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:12|13|14
08-08 02:11:10.931  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:15|16|17
08-08 02:11:10.933  32427-32443/? D/MyWidgetViewsFactory﹕ getViewAt(2):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@16dbf3ef
08-08 02:11:10.933  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:18|19|20
08-08 02:11:10.933  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:21|22|23
08-08 02:11:10.933  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:24|25|26
08-08 02:11:10.936  32427-32443/? D/MyWidgetViewsFactory﹕ getViewAt(3):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@19d3defc
08-08 02:11:10.936  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:27|28|29
08-08 02:11:10.936  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:30|31|32
08-08 02:11:10.936  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:33|34|35
08-08 02:11:10.938  32427-32443/? D/MyWidgetViewsFactory﹕ getViewAt(4):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@ee985
08-08 02:11:10.938  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:36|37|38
08-08 02:11:10.938  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:39|40|41
08-08 02:11:10.938  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:42|43|44
08-08 02:11:10.941  32427-32443/? D/MyWidgetViewsFactory﹕ getViewAt(8):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@335e23da
08-08 02:11:10.941  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:72|73|74
08-08 02:11:10.941  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:75|76|77
08-08 02:11:10.941  32427-32443/? D/MyWidgetViewsFactory﹕ subitem:78|79|80
08-08 02:11:10.943  32427-32447/? D/MyWidgetViewsFactory﹕ getViewAt(9):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@229de00b
08-08 02:11:10.943  32427-32447/? D/MyWidgetViewsFactory﹕ subitem:81|82|83
08-08 02:11:10.943  32427-32447/? D/MyWidgetViewsFactory﹕ subitem:84|85|86
08-08 02:11:10.943  32427-32447/? D/MyWidgetViewsFactory﹕ subitem:87|88|89
08-08 02:11:10.945  32427-32444/? D/MyWidgetViewsFactory﹕ getViewAt(5):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@2afdeee8
08-08 02:11:10.945  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:45|46|47
08-08 02:11:10.945  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:48|49|50
08-08 02:11:10.945  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:51|52|53
08-08 02:11:10.948  32427-32444/? D/MyWidgetViewsFactory﹕ getViewAt(7):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@1c599901
08-08 02:11:10.948  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:63|64|65
08-08 02:11:10.948  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:66|67|68
08-08 02:11:10.948  32427-32444/? D/MyWidgetViewsFactory﹕ subitem:69|70|71
08-08 02:11:10.951  32427-32447/? D/MyWidgetViewsFactory﹕ getViewAt(6):de.mayerhofersimon.listviewproblem.MyWidgetViewsFactory$Item@368aa3a6
08-08 02:11:10.951  32427-32447/? D/MyWidgetViewsFactory﹕ subitem:54|55|56
08-08 02:11:10.951  32427-32447/? D/MyWidgetViewsFactory﹕ subitem:57|58|59
08-08 02:11:10.951  32427-32447/? D/MyWidgetViewsFactory﹕ subitem:60|61|62

因此数据传递正确。它只是没有得到正确显示...

BTW：它应该是这样的：http://c.maysi.de/cB8K

可能是，问题是因为嵌套的远程视图？因为所有外部远程视图都显示正确...

Answer 1

您对ListView回收问题背后的想法是正确的。你需要了解事情在地面上的运作方式。

MVC模式

Android图形适用于MVC模式，即模型视图和控制器模式。 Model是您的数据，在您的情况下是数据库，View是您的布局或图形部分，例如ListView或RecyclerView或RemoteView。控制器在数据更新，父视图或ViewGroup之后更改视图，RemoteViewsService.RemoteViewsFactory是控制器。我建议通过谷歌搜索MVC模型进一步阅读。

如何实施模式？

每次数据更改时，控制器都应更新视图。通过覆盖getViewAt(int position)，Android框架可让您通过数据在给定位置显示您的视图。控制器调用getViewAt(int position)以获取ListView或RecyclerView中给定位置的视图。 ListView或RecyclerView仅在屏幕上呈现可见行。例如，如果ListView中有100个项目，并且屏幕上只显示7个项目，则会调用getItemAt（int）7次。每次滚动时，都会为可见行调用getItemAt（int）。 ListView和RemoteView可以自由地回收/重用getItemAt（int position）返回的先前传递的View。它确保应用程序的图形部分消耗的内存有限

为什么会出现奇怪的行为？

首先，屏幕上每个可见的东西都是View，例如TextView，ImageView和ListView等。如果没有，它就无法在屏幕上显示。 RemoteView不是视图。使用RemoteView（View + Data）传递要显示的布局和数据。

这里我指的是您的截屏视频以获取解释。

1）初始化：您的案例中的ListView，最初会根据屏幕上的可见空间创建6行，如果{{1}则调用getViewAt(int position)返回1.我请求检查List适配器的getCount（）的返回值   2）向下滚动：getCount()没有任何反应并呈现新行。
  3）你向上滚动：再次调用getPositionAt（int position）并传回RemoteView。现在可以看到两行。我请求检查getCount（）返回值。它应该是2，如果不是原因可以通过ListView缓存行。
  4）向下滚动：ListView没有任何反应，并且渲染了新的行。
  5）你向上滚动：参考3. getCount（）应为3，依此类推。

你应该做什么？

根据您的实现，您只创建了一次RemoteView并尝试在ListView重用相同的视图，可能是为了节省布局通胀时间。
要解决此问题，每次调用getItemAt(int)时，必须提供新鲜 RemoteView。

getItemAt(int)

Answer 2

我自己找到了答案。

要解决在滚动和调整大小时奇怪添加视图的问题，您必须在添加了子视图的布局上调用func TokenProcessing(w http.ResponseWriter, r *http.Request) { token := r.URL.Query().Get("token") // dynamically generated from parsed URL // code to do something with said token }：

removeAllViews

并且未显示视图的问题是由于颜色：添加后

@Override
    public RemoteViews getViewAt(int position) {
        ...
        RemoteViews itemView = new RemoteViews(context.getPackageName(), R.layout.widget_listview_item);
        itemView.removeAllViews(R.id.linearLayout_item_body);
        ...
        return itemView;
    }

显示所有视图：

Answer 3

您的问题似乎在：

if(stundenContainer[j]!=null)
    Log.d("VplanWidgetViewsFactory", "stundenContainer["+j+"]:" + stundenContainer[j].toString());
else
    Log.d("VplanWidgetViewsFactory", "stundenContainer[" + j + "]:null");

if (stundenContainer[j] == null) {
    //Freistunde
    Log.d("VplanWidgetViewsFactory", "Freistunde");
    // HERE -----
    stunden.add(new RemoteViews(context.getPackageName(), R.layout.fragment_stunde_widget));
    faecher.add(new RemoteViews(context.getPackageName(), R.layout.fragment_fach));
    stunden.get(stunden.size() - 1).setTextViewText(R.id.textView_lesson_nr, "" + (j + 1) + ".");
 } else if (!stundenContainer[j].get(0).getSubject().equals("ignore")) {
     Log.d("VplanWidgetViewsFactory", "stundenContainer[j].get(0).getSubject(): " + stundenContainer[j].get(0).getSubject());
     // HERE -----
     stunden.add(new RemoteViews(context.getPackageName(), R.layout.fragment_stunde_widget));

您要将它添加两次..，但仅当第一项未被忽略时，它才会显示为随机。

stunden.add(new RemoteViews(context.getPackageName(), R.layout.fragment_stunde_widget));

小部件中的ListView在滚动和调整大小时添加随机项（嵌套的远程视图）

3 个答案: