Question

我正在处理两个不同的图表，一个是RadarChart，用于将“评估”中的所有“类别”的得分与其他“评估”进行比较，另一个是分组的BarChart，允许用户在一个图表中选择“类别”。 “评估”，并将其与其他“评估”进行比较。从Firebase提取数据，并将DatabaseReferences存储在ArrayList中。我的RadarChart使用以下代码并显示以下结果：

        ArrayList<RadarDataSet> dataSets = new ArrayList<>();
        ArrayList<IRadarDataSet> allDataSets = new ArrayList<>();
        for(int i = 0; i < assessmentKeys.size(); i++) {
            final ArrayList<RadarEntry> radarEntries = new ArrayList<>();
            final int trackerIndex = i;
            dataSets.add(trackerIndex, new RadarDataSet(radarEntries, assessmentName.get(i)) );
            mAssessmentCategoryRefs.get(i).addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                    if(dataSnapshot.exists()) {
                        for(DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
                            Category category = postSnapshot.getValue(Category.class);
                            radarEntries.add(new RadarEntry((float)category.getCategoryScore(), category.getNumber() - 1));
                        }
                    }
                }
                @Override
                public void onCancelled(DatabaseError databaseError) {
                }
            });
            Random random = new Random();
            int randomR = random.nextInt(256);
            int randomG = random.nextInt(256);
            int randomB = random.nextInt(256);
            dataSets.get(trackerIndex).setColor(Color.rgb(randomR, randomG, randomB));
            dataSets.get(trackerIndex).setFillColor(Color.rgb(randomR, randomG, randomB));
            dataSets.get(trackerIndex).setDrawFilled(true);
            allDataSets.add(dataSets.get(trackerIndex));
        }

        RadarData data = new RadarData(allDataSets);

由于RadarEntry，BarEntry，BarDataSet，RadarDataSet，IBarDataSet和IRadarDataSet在它们之间共享父类，因此我认为我将能够以与RadarChart相同的方式将数据加载到分组的BarChart中。为了进行概念验证，我使用以下代码在尝试从Firebase中拉出之前验证它是否可以工作：

        final ArrayList<BarDataSet> dataSets = new ArrayList<>();
            ArrayList<IBarDataSet> allDataSets = new ArrayList<>();

            for(int j = 0; j < assessmentKeys.size(); j++ ) {
                final int jTracker = j;
                final ArrayList<BarEntry> entries = new ArrayList<>();
                dataSets.add(j, new BarDataSet(entries, assessmentName.get(j)));
                Log.d("Received_Data", "Getting data for " + assessmentName.get(j));

                for(int k = 0; k < categoryNames.size(); k++) {
                    entries.add(new BarEntry(k, k+1));
                }

                Random random = new Random();
                int randomR = random.nextInt(256);
                int randomG = random.nextInt(256);
                int randomB = random.nextInt(256);
                dataSets.get(j).setColor(Color.rgb(randomR, randomG, randomB));
                allDataSets.add(dataSets.get(j));
            }

这产生了这张图：

当我添加要从Firebase中提取的代码时，RadarChart不会发生奇怪的事情：

            final ArrayList<BarDataSet> dataSets = new ArrayList<>();
            ArrayList<IBarDataSet> allDataSets = new ArrayList<>();

            for(int j = 0; j < assessmentKeys.size(); j++ ) {
                final int jTracker = j;
                final ArrayList<BarEntry> entries = new ArrayList<>();
                dataSets.add(j, new BarDataSet(entries, assessmentName.get(j)));
                Log.d("Received_Data", "Getting data for " + assessmentName.get(j));

                for(int k = 0; k < categoryNames.size(); k++) {
                    final String categoryName = categoryNames.get(k);
                    final int kTracker = k;
                    mAssessmentCategoryRefs.get(jTracker).addListenerForSingleValueEvent(new ValueEventListener() {
                        @Override
                        public void onDataChange(DataSnapshot dataSnapshot) {
                            if(dataSnapshot.exists()) {
                                for(DataSnapshot postSnapShot : dataSnapshot.getChildren()) {
                                    Category category = postSnapShot.getValue(Category.class);
                                    if(categoryName.equals(category.getName())) {
                                        entries.add(new BarEntry(kTracker, (float)category.getCategoryScore()));
                    Log.d(TAG, "Added " + category.getName() + " to entries");
                                    } else {
                    Log.d(TAG, "Skipped " + category.getName());
                    }
                                }
                            }
                        }
                        @Override
                        public void onCancelled(DatabaseError databaseError) {
                        }
                    });
                }

                Random random = new Random();
                int randomR = random.nextInt(256);
                int randomG = random.nextInt(256);
                int randomB = random.nextInt(256);
                dataSets.get(j).setColor(Color.rgb(randomR, randomG, randomB));
                allDataSets.add(dataSets.get(j));
            }
            BarData data = new BarData(allDataSets);
            mBarChart.setData(data);
            data.notifyDataChanged();
            mBarChart.notifyDataSetChanged();
            mBarChart.invalidate();

即使我的日志显示该数据正确地跳过了与所选名称不匹配的类别，也没有添加该类别的分数，即使我的日志显示该数据也没有。

这是什么原因？起初，我认为这可能是由于从Firebase提取数据的异步特性造成的，但是如果是这种情况，我的RadarChart也会遇到同样的问题。据我所知RadarEntry和BarEntry之间的唯一真正区别是，索引是RadarEntry中的第二个参数，但是BarEntry中的第一个参数。以相同的方式被加载到DataSet中，以相同的方式将DataSet加载到ArrayList<IBarDataSet>中，但是由于某种原因一个起作用，而另一个则不起作用。有人知道这个问题是什么吗？这是MPAndroidChart的显式BarEntry的错误吗？

Answer 1

我找到了解决方法。首先，我必须创建一个在onCreate()中调用的初始化方法：

    private Map<String, Map<String, Float>> assessmentData = new HashMap<>();
    private void initAssessmentData() {
        for(int i = 0; i < assessmentKeys.size(); i++) {
            final Map<String, Float> categoryNameScore = new HashMap<>();
            mAssessmentCategoryRefs.get(i).addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                    if(dataSnapshot.exists()) {
                        for(DataSnapshot postSnapShot : dataSnapshot.getChildren()) {
                            Category category = postSnapShot.getValue(Category.class);
                            categoryNameScore.put(category.getName(), (float) category.getCategoryScore());
                        }
                    }
                }
                @Override
                public void onCancelled(DatabaseError databaseError) {
                }
            });
            assessmentData.put(assessmentKeys.get(i), categoryNameScore);
        }
    }

然后将数据放入图中，我只需要将代码更改为此：

final ArrayList<BarDataSet> dataSets = new ArrayList<>();
            ArrayList<IBarDataSet> allDataSets = new ArrayList<>();
            final BarData data = new BarData(allDataSets);

            for(int j = 0; j < assessmentKeys.size(); j++ ) {
                final int jTracker = j;
                final ArrayList<BarEntry> entries = new ArrayList<>();
                dataSets.add(j, new BarDataSet(entries, assessmentName.get(j)));
                Log.d("Received_Data", "Getting data for " + assessmentName.get(j));


                for(String key : assessmentData.keySet()) {
                    if(key.equals(assessmentKeys.get(j))) {
                        Map<String, Float> categoryData = assessmentData.get(key);
                        for(String key2 : categoryData.keySet()) {
                            if(categoryNames.contains(key2)) {
                                entries.add(new BarEntry(categoryNames.indexOf(key2), categoryData.get(key2)));
                            }
                        }
                    }
                }

                Random random = new Random();
                int randomR = random.nextInt(256);
                int randomG = random.nextInt(256);
                int randomB = random.nextInt(256);
                dataSets.get(j).setColor(Color.rgb(randomR, randomG, randomB));
                allDataSets.add(dataSets.get(j));
                data.notifyDataChanged();
                mBarChart.notifyDataSetChanged();
                mBarChart.invalidate();

异步添加到数据集中时，BarEntry和RadarEntry之间的区别

1 个答案: