二维画图引擎-画圆、半圆、弧线
// // QHCircle.m // 绘图 // #import "QHCircle.h" @implementation QHCircle // Only override drawRect: if you perform custom drawing. // An empty implementation adversely affects performance during animation. /** * 当View第一次显示的时候调用 * * @param rect */ - (void)drawRect:(CGRect)rect { // Drawing code //仅仅会调一次 CGContextRef ctx = UIGraphicsGetCurrentContext(); //2.画1/4圆 CGContextMoveToPoint(ctx, 100, 100); CGContextAddLineToPoint(ctx, 100, 150); CGContextAddArc(ctx, 100, 100, 50, -M_PI_2, M_PI, 1); CGContextClosePath(ctx); [[UIColor redColor]set]; CGContextFillPath(ctx); drawArc(); drawCircle(); } void drawArc() { CGContextRef ctx = UIGraphicsGetCurrentContext(); // 2.画圆弧 // x\y : 圆心 // radius : 半径 // startAngle : 開始角度 // endAngle : 结束角度 // clockwise : 圆弧的伸展方向(0:顺时针, 1:逆时针) CGContextAddArc(ctx, 100, 100, 50, M_PI_2, M_PI, 0); CGContextFillPath(ctx); } void drawCircle() { CGContextRef ctx = UIGraphicsGetCurrentContext(); //画圆 CGContextAddEllipseInRect(ctx, CGRectMake(50, 10, 100, 100)); CGContextSetLineWidth(ctx, 10); CGContextStrokePath(ctx); } @end
时间: 2024-10-15 23:38:58