为什么 GraphView 不能绘制这些点？如果第二个点的 x 值小于第一个点

Question

如果第二个点的 x 值小于第一个点，android 的 GraphView 无法绘制这些点。

<com.jjoe64.graphview.GraphView
    android:id="@+id/GPH_graph"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    style="@style/STL_Graph"/>


DataPoint[] DP_Array = new DataPoint[]{new DataPoint( 0, 0), new DataPoint(-10,10)};
LineH1 = new LineGraphSeries<>(DP_Array);
LineH1.setColor(getResources().getColor(R.color.black));
GPH_graph.addSeries(LineH1);

我想把这些点画成这张图

Answer 1

我用下面的代码解决了这个问题：

List<LineGraphSeries<DataPoint>> Series;

Series = SetSeries(DP_Array);

for (int i = 0; i < Series.size(); i++)
{

    GPH_graph.addSeries(Series.get(i));    
    
}

List<LineGraphSeries<DataPoint>> SetSeries(DataPoint[] AllData)
    {

        List<LineGraphSeries<DataPoint>> LineGraphSeriesList = new ArrayList<> ();
        DataPoint[] DP;

        boolean bol_Forward = true;
        int NumForward = 0;
        int NumBackward = 0;

        for(int i = 1;i < AllData.length;i++)
        {

            if(AllData[i].getX() >= AllData[i-1].getX())
            {

                NumForward++;
                bol_Forward = true;

            }
            else
            {

                NumBackward++;
                bol_Forward = false;

            }

            if(NumBackward>0 & NumForward>0)
            {

                if(bol_Forward == false)
                {

                    DP = new DataPoint[NumForward + 1];
                    for (int A = 0;A < NumForward + 1;A++)
                    {

                        DP[NumForward - A] = new DataPoint(AllData[i - 1 - A].getX(),AllData[i - 1 - A].getY());

                    }

                    LineGraphSeriesList.add(new LineGraphSeries<>(DP));
                    NumForward = 0;

                }
                else
                {

                    DP = new DataPoint[NumBackward + 1];
                    for (int A = 0;A < NumBackward + 1;A++)
                    {

                        DP[A] = new DataPoint(AllData[i - 1 - A].getX(),AllData[i - 1 - A].getY());

                    }

                    LineGraphSeriesList.add(new LineGraphSeries<>(DP));
                    NumBackward = 0;

                }

                Num++;

            }

        }

        return LineGraphSeriesList;

    }

为什么 GraphView 不能绘制这些点？如果第二个点的 x 值小于第一个点

Why can not GraphView plot these points? If the second point has a x value less than first point

android

android-graphview