iphone - 如何在半圆形图案中绘制点

Question

如何以编程方式在 iPhone 中以半圆形图案绘制点？

Answer 1

我确实使用了下面的代码

    CGContextRef ctx = UIGraphicsGetCurrentContext();

float angle = 0;

float centerX = self.frame.size.width/2;
float centerY = self.frame.size.width/2;

float startX = 0.0;
float startY = 0.0;
for (int i = 0; i < 8 ; i++) {

    startX = centerX +  cos(angle) * (radius + 50) - 5  ;
    startY = centerY +  sin(angle) * (radius + 50 ) - 5;
    CGContextFillEllipseInRect(ctx, CGRectMake(startX,  startY,  5, 5));
    [[UIColor blackColor] setStroke];
    angle-= M_PI/7;
}