CGFloat x1,y1;
x1=0;y1=0;
int l = self.frame.size.width;//直径
int r = l/2;
if (point.x<r && point.y<r){
x1 = point.x - r;
y1 = r - point.y;}
if (point.x>r && point.y<r){
x1 = point.x - r;
y1 = r - point.y; }
if (point.x<r && point.y>r) {
x1 = point.x-r;
y1 = r - point.y;}
if (point.x>r&& point.y>r) {
x1 = point.x - r;
y1 = r - point.y;}
if (x1*x1+y1*y1<r*r){
return YES;
}else{
return NO;
}
