Java Android MP图表highlightValue不工作,引发ArrayIndexOutOfBoundsException
我正在玩Android lib来绘制很棒的图表 我试图突出显示图表上的值,但它没有将突出显示放置到正确的位置,或者抛出ArrayIndexOutOfBoundsException 我为它做了一个小的虚拟项目。当用户单击“下一步”按钮时,突出显示应向正方向移动。Java Android MP图表highlightValue不工作,引发ArrayIndexOutOfBoundsException,java,android,kotlin,mpandroidchart,combinedchart,Java,Android,Kotlin,Mpandroidchart,Combinedchart,我正在玩Android lib来绘制很棒的图表 我试图突出显示图表上的值,但它没有将突出显示放置到正确的位置,或者抛出ArrayIndexOutOfBoundsException 我为它做了一个小的虚拟项目。当用户单击“下一步”按钮时,突出显示应向正方向移动。 public class MainActivity extends AppCompatActivity implements View.OnClickListener { final int DATA_MAX_COUNT =
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
final int DATA_MAX_COUNT = 30;
List<MyData> list = new ArrayList<>(); ///<Dummy data stored in here
List<Entry> entries = new ArrayList<>(); ///<Entries for MP Chart
int highlightIndex = 0; ///<Chart's data index to be highlighted
CombinedChart combinedChart; ///<I use combined chart because there will be more data sets added later on
Button prevBtn; ///<Button for highlight control
Button nextBtn; ///<Button for highlight control
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
combinedChart = (CombinedChart) findViewById(R.id.chart);
prevBtn = (Button) findViewById(R.id.prev_btn);
prevBtn.setOnClickListener(this);
nextBtn = (Button) findViewById(R.id.next_btn);
nextBtn.setOnClickListener(this);
generateData();
drawChart();
}
@Override
public void onClick(View v) {
//Clicking buttons should move the highlighted value
if (v.equals(prevBtn)) {
if (highlightIndex > 0) {
highlightIndex--;
}
} else if (v.equals(nextBtn)) {
if (highlightIndex + 1 < DATA_MAX_COUNT) {
highlightIndex++;
}
}
//Does not work, throws exception
//combinedChart.highlightValue(new Highlight(highlightIndex, 0, 0));
//Does not work, throws exception
//combinedChart.highlightValue(highlightIndex, 0, false);
//Exception
// java.lang.ArrayIndexOutOfBoundsException: length=10; index=-1
// at com.github.mikephil.charting.data.CombinedData.getDataByIndex(CombinedData.java:152)
// at com.github.mikephil.charting.data.CombinedData.getEntryForHighlight(CombinedData.java:183)
// at com.github.mikephil.charting.charts.Chart.highlightValue(Chart.java:635)
// at com.github.mikephil.charting.charts.Chart.highlightValue(Chart.java:613)
//Works, but highlights value on chart with like x=0 and y= 190, wtf?
combinedChart.highlightValue(combinedChart.getHighlighter().getHighlight(highlightIndex, 0));
}
//Generating random data to a list
public void generateData() {
for (int i = 0; i < DATA_MAX_COUNT; i++) {
MyData myData = new MyData(new Random().nextInt(100) + 100);
list.add(myData);
}
}
//Simple func for adding data to entries and drawing chart
private void drawChart() {
CombinedData combinedData = new CombinedData();
for (int i = 0; i < list.size(); i++) {
MyData myData = list.get(i);
entries.add(new Entry(i, myData.getValue(), myData));
}
LineDataSet lineDataSet = new LineDataSet(entries, "My data list");
lineDataSet.setHighLightColor(Color.RED);
lineDataSet.setHighlightLineWidth(3);
LineData lineData = new LineData();
lineData.addDataSet(lineDataSet);
combinedData.setData(lineData);
combinedChart.setData(combinedData);
combinedChart.invalidate();
}
//Dummy data class
public static class MyData {
private int value;
public MyData(int value) {
this.value = value;
}
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
}
}
以下是解决方案:
Highlight high = new Highlight(highlightIndex, 0, 0);
high.setDataIndex(0);
combinedChart.highlightValue(high, false);
您需要添加high.setDataIndex(0)代码>行
解释:
在高亮显示中
构造函数的第一个参数是X值,即增加或减少的值。第二个是要选择的图的索引。因为只有一个,所以在那里指定0。您还应该第二次指定它high.setDataIndex(0)代码>(否则将被视为-1,bug!),您的代码将正常工作:
以下是解决方案:
Highlight high = new Highlight(highlightIndex, 0, 0);
high.setDataIndex(0);
combinedChart.highlightValue(high, false);
您需要添加high.setDataIndex(0)代码>行
解释:
在高亮显示中
构造函数的第一个参数是X值,即增加或减少的值。第二个是要选择的图的索引。因为只有一个,所以在那里指定0。您还应该第二次指定它high.setDataIndex(0)代码>(否则将被视为-1,bug!),您的代码将正常工作: