如何以半圆形图案绘制圆点

时间:2013-08-19 10:21:12

标签: iphone ios objective-c drawrect cgcontext

如何以编程方式在iphone中以半圆形图案绘制圆点?

2 个答案:

答案 0 :(得分:2)

我使用了以下代码

    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;
}

答案 1 :(得分:1)

您可以这样使用Quartz 2D: -

- (void)drawRect:(CGRect)rect {
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetLineWidth(context, 20.0);
    CGContextSetStrokeColorWithColor(context, 
       [UIColor blueColor].CGColor);
    CGFloat dashArray[] = {2,6,4,2};
    CGContextSetLineDash(context, 3, dashArray, 4);
    CGContextMoveToPoint(context, 10, 200);
    CGContextAddQuadCurveToPoint(context, 150, 10, 300, 200);
    CGContextStrokePath(context);
}

请查看以下所有图纸示例: -

http://www.techotopia.com/index.php/An_iOS_5_iPhone_Graphics_Drawing_Tutorial_using_Quartz_2D