Question

我在Android中的AchartEngine Scatter图表中遇到了一个问题。在将缩放设置为某个级别后平移时，每个点之间的线条会消失。我曾尝试将hardwareAcceleration设置为false，并将setLayerType设置为null和all。但问题仍然存在。

Achartengine版本1.1.0。 Android设备 - Galaxy S4，S3。你能帮帮我吗？

屏幕截图位于http://i.stack.imgur.com/hq5r4.png

Screenshot is pasted down - with no line between chart points 感谢

JRH

Answer 1

经过两天的努力，我能够解决问题。这是由于Float.NaN的一个Path值，同时绘制线。

问题是AbstractChart - ＆gt; drawPath方法。在那个calculateDrawPoints（）方法中返回一个float数组，在一个case中包含Float.NaN。我不知道背后的问题。但我可以用Canvas.drawLine方法克服它。

由于

JRH

Answer 2

因为AbstarctChart ==＆gt; calculateDrawPoints（）方法返回包含Float.NaN

的float数组

因为在计算过程中，有时值返回0，并且在将值除以0之后，我们得到Float.NaN 除以零的任何内容都是未定义的

因此，请使用以下

更新calculateDrawPoints（）方法代码

private static float[] calculateDrawPoints(float p1x, float p1y, float p2x, float p2y,
      int screenHeight, int screenWidth) {
    float drawP1x = 0;
    float drawP1y;
    float drawP2x = 0;
    float drawP2y;

    if (p1y > screenHeight) {
      // Intersection with the top of the screen
      float m = (p2y - p1y) / (p2x - p1x);
      if (m != 0) {
        drawP1x = (screenHeight - p1y + m * p1x) / m;
      } else {
        drawP1x = (screenHeight - p1y + m * p1x);
      }
      drawP1y = screenHeight;

      if (drawP1x < 0) {
        // If Intersection is left of the screen we calculate the intersection
        // with the left border
        drawP1x = 0;
        drawP1y = p1y - m * p1x;
      } else if (drawP1x > screenWidth) {
        // If Intersection is right of the screen we calculate the intersection
        // with the right border
        drawP1x = screenWidth;
        drawP1y = m * screenWidth + p1y - m * p1x;
      }
    } else if (p1y < 0) {
      float n = p2x - p1x;
      float m = 0;
      if (n != 0) {
        m = (p2y - p1y) / n;
      } else {
        m = (p2y - p1y);
      }
      if (m != 0) {
        drawP1x = (-p1y + m * p1x) / m;
      } else {
        drawP1x = (-p1y + m * p1x);
      }
      drawP1y = 0;
      if (drawP1x < 0) {
        drawP1x = 0;
        drawP1y = p1y - m * p1x;
      } else if (drawP1x > screenWidth) {
        drawP1x = screenWidth;
        drawP1y = m * screenWidth + p1y - m * p1x;
      }
    } else {
      // If the point is in the screen use it
      drawP1x = p1x;
      drawP1y = p1y;
    }

    if (p2y > screenHeight) {
      float n = (p2x - p1x);
      float m = 0;
      if (n != 0) {
        m = (p2y - p1y) / n;
      } else {
        m = (p2y - p1y);
      }
      if (m != 0) {
        drawP2x = (screenHeight - p1y + m * p1x) / m;
      } else {
        drawP2x = (screenHeight - p1y + m * p1x);
      }

      drawP2y = screenHeight;
      if (drawP2x < 0) {
        drawP2x = 0;
        drawP2y = p1y - m * p1x;
      } else if (drawP2x > screenWidth) {
        drawP2x = screenWidth;
        drawP2y = m * screenWidth + p1y - m * p1x;
      }
    } else if (p2y < 0) {
      float n = (p2x - p1x);
      float m = 0;
      if (n != 0) {
        m = (p2y - p1y) / n;
      } else {
        m = (p2y - p1y);
      }
      if (m != 0) {
        drawP2x = (-p1y + m * p1x) / m;
      } else {
        drawP2x = (-p1y + m * p1x);
      }
      drawP2y = 0;
      if (drawP2x < 0) {
        drawP2x = 0;
        drawP2y = p1y - m * p1x;
      } else if (drawP2x > screenWidth) {
        drawP2x = screenWidth;
        drawP2y = m * screenWidth + p1y - m * p1x;
      }
    } else {
      // If the point is in the screen use it
      drawP2x = p2x;
      drawP2y = p2y;
    }
    return new float[] { drawP1x, drawP1y, drawP2x, drawP2y };
  }

这将解决您的问题

android中的AchartEngineLine图表 - 行平移时消失

2 个答案: