ios 贝塞尔画图

CGContextRef context = UIGraphicsGetCurrentContext();

//写文字

CGContextSetRGBFillColor(context, 1, 0, 0, 1.0);//设置填充颜色

UIFont *font = [UIFont boldSystemFontOfSize:15.0];

//    NSString *str = @"圆";

//    [str drawInRect:<#(CGRect)#> withAttributes:<#(NSDictionary *)#>];

//边框圆

CGContextSetRGBStrokeColor(context, 1, 1, 1, 1.0);//画笔颜色

CGContextSetLineWidth(context, 1.0);//线的宽度

CGContextAddArc(context, 50, 100, 20, 0, 2*M_PI, 0);

CGContextDrawPath(context, kCGPathStroke);//绘制路径

//填充圆

CGContextAddArc(context, 120, 100, 25, 2*M_PI, 0, 0);//添加一个圆

CGContextDrawPath(context, kCGPathFill);//绘制填充

//填充圆 有边框

CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);

CGContextSetLineWidth(context, 3.0);

CGContextAddArc(context, 200, 100, 30, 0, 2*M_PI, 0);

//kCGPathFill填充非零绕数规则,kCGPathEOFill表示用奇偶规则,kCGPathStroke路径,kCGPathFillStroke路径填充,kCGPathEOFillStroke表示描线，不是填充

CGContextDrawPath(context, kCGPathFillStroke);

//画线

CGPoint aPoints[2];

aPoints[0] = CGPointMake(0, 0);

aPoints[1] = CGPointMake(self.frame.size.width, self.frame.size.height);

CGContextAddLines(context, aPoints, 2);

CGContextDrawPath(context, kCGPathStroke);

//画弧

CGContextSetRGBStrokeColor(context, 1, 1, 0.5, 1.0);

CGContextMoveToPoint(context, 50, 200);

CGContextAddArcToPoint(context, 58, 180, 66, 200, 10);

CGContextStrokePath(context);

//画矩形

CGContextStrokeRect(context, CGRectMake(50, 250, 50, 50));

CGContextFillRect(context, CGRectMake(110, 250, 50, 50));

//矩形 并填充颜色

CGContextSetLineWidth(context, 2.0);

CGContextSetFillColorWithColor(context, [UIColor greenColor].CGColor);

CGContextAddRect(context, CGRectMake(200, 250, 50, 50));

CGContextDrawPath(context, kCGPathFillStroke);

//第一种填充方式

CAGradientLayer *gradient1 = [CAGradientLayer layer];

gradient1.frame = CGRectMake(50, 320, 60, 30);

gradient1.colors = [NSArray arrayWithObjects:(id)[UIColor whiteColor].CGColor,(id)[UIColor grayColor].CGColor,(id)[UIColor blackColor].CGColor,(id)[UIColor yellowColor].CGColor,(id)[UIColor blueColor].CGColor,(id)[UIColor redColor].CGColor,(id)[UIColor greenColor].CGColor,(id)[UIColor orangeColor].CGColor,(id)[UIColor brownColor].CGColor, nil];

[self.layer insertSublayer:gradient1 atIndex:0];

//第二种填充方式

CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();

CGFloat colors[] =

{

1,1,1, 1.00,

1,1,0, 1.00,

1,0,1, 1.00,

0,1,1, 1.00,

0,0,1, 1.00,

1,0,0, 1.00,

0,1,0, 1.00,

0,0,0, 1.00,

};

CGGradientRef gradient = CGGradientCreateWithColorComponents(rgb, colors, nil, sizeof(colors)/(sizeof(colors[0])*4));

CGColorSpaceRelease(rgb);

CGContextSaveGState(context);

CGContextMoveToPoint(context, 150, 320);

CGContextAddLineToPoint(context, 170, 320);

CGContextAddLineToPoint(context, 170, 350);

CGContextAddLineToPoint(context, 150, 350);

CGContextClip(context);

CGContextDrawLinearGradient(context, gradient, CGPointMake(100, 320), CGPointMake(130, 350), kCGGradientDrawsAfterEndLocation);

CGContextRestoreGState(context);