Question

我正在开发一款用于提高驾驶速度的应用。我需要根据速度和时间（秒）绘制图形等线条。时间值是x轴，速度值是y轴。我尝试了随机值，它的工作原理。但是，如果我为更新的值绘制它，它不起作用。试着帮助我。提前谢谢！

class MyView extends View {


Paint paint = new Paint();
Path path = new Path();
 float[] x=new float[30];
 float[] y=new float[30];
 int i=0;

public MyView(Context context) {
    super(context);

while(i<10)
   {
    x[i]= seconds; 
    y[i]= Speed;

    y[i]=(float) (0.262*y[i]); // this is for drawing my y-axis to certain range

    System.out.println("Current seconds:"+x[i]);
    System.out.println("Current speed:"+y[i]);

    seconds+= 60;  //   update for every 60 seconds
    i++;

    }
}
public void onDraw (Canvas canvas) {


       path.moveTo(x[0],y[0]);

    for (int i = 1; i < 10; i++) {

               path.lineTo(x[i],y[i]);

       }
        paint.setStyle(Style.STROKE);
        paint.setStrokeWidth(3);
        paint.setColor(0xFFFF5050);
        paint.setAntiAlias(true);
        System.out.println("Height:"+relativelayout5.getHeight());
        canvas.translate(0,relativelayout5.getHeight());   // reset where 0,0 is located
        canvas.scale(1,-1);
        canvas.drawPath(path, paint);
       paint.setShadowLayer(0, 0, 0, 0); 
       paint.setStrokeJoin(Paint.Join.ROUND);
     }  

}

i在MainActivity中使此视图无效。

在android中动态绘制更新值的行

0 个答案: