                        课程
                    
                        /移动开发
                        
                            /Android
                        
                        /Android图案解锁

角度计算有问题

计算角度这个没有讲真的有好大问题

qq_箭在弦上_0

2015-06-10

源自：Android图案解锁 4-1

关注问题我要回答

1470

操作

收起

3 回答

学习123456
2015-06-11

/**
   * 获取角度
   * @param a
   * @param b
   * @return 角度
   */
   public float getDegress(Point a,Point b){
       float ax=a.x;
       float ay=a.y;
       float bx=b.x;
       float by=b.y;
       float degress=0;
       if(bx==ax){
           if(by>ay){
               degress=90;
           }else if(by<ay){
               degress=270;
           }
       }else if(by==ay){
           if(bx>ax){
               degress=0;
           }else if(bx<ax){
               degress=180;
           }
       }else if(bx>ax){//-90~90
           if(by>ay){ //-90~0
               degress=WithPoint(Math.abs(ax-bx),Math.abs(ay-by));
           }else if(by<ay){//0~90
               degress=-WithPoint(Math.abs(ax-bx),Math.abs(ay-by));
           }
       }else if(bx<ax){//90~270
           if(by>ay){//180~270
               degress=-WithPoint(Math.abs(ax-bx),Math.abs(ay-by))+180;
           }else if(by<ay){//90~180
               degress=WithPoint(Math.abs(ax-bx),Math.abs(ay-by))+180;
           }
       }
       return degress;
   }
   //求角度
   public float WithPoint(float x,float y){
       float dushu=Math.round(Math.atan(y/x)/Math.PI*180);
       return dushu;
   }

0 回复有任何疑惑可以回复我~

收起回答

qq_箭在弦上_0 提问者

非常感谢！

2015-08-07 回复有任何疑惑可以回复我~

MMC
2016-06-08

/**
* 获取角度
* @param a
* @param b
* @return 角度
* */

public float getDegrees(Point a,Point b){
float aX = a.x;
float aY = a.y;
float bX = b.x;
float bY = b.y;
float tan;
float degrees = 0;
if (aX == bX){ //90度或270度
if(bY > aY){ //在y轴下边
degrees = 90;
} else if(bY < aY){
degrees = 270;
}
}else if(aY == bY){ // 0 度或180度
if (aX>bX){
degrees = 180;
}else if(aX<bX){
degrees = 0 ;
}
}else {
tan=(b.y-a.y)/(b.x-a.x);
degrees= (float) ((float)Math.atan(tan)/Math.PI*180);
if (a.y<b.y&&a.x>b.x){
degrees=180+degrees; //270°-360°
}

if (a.x>b.x&&a.y > b.y) { //180°-270°
degrees=180+degrees;
}

}
return degrees;
}