Xcode Quartz 2D 绘图

//绘图  继承与UIView

- (void)drawRect:(CGRect)rect

{

    //绘制图片

    [self drawImage];

    //绘制文本

    [self drawText];

    //绘制线

    [self drawLine];

    

    //矩形

    [self drawRecttang];

    [self drawArc];

    

}

//弧线

-(void)drawArc{

    //得到上下文

    CGContextRef ref = UIGraphicsGetCurrentContext();

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

    CGContextMoveToPoint(ref, 150, 150);

    //参数   圆心  半径  顺时针逆时针

    //饼型图自定义

    //所占的比例可以自定义

    CGContextAddArc(ref, 150, 150, 100, 0, 100*M_PI /180, 0);

    CGContextFillPath(ref);

    

    CGContextSetFillColorWithColor(ref, [UIColor blueColor].CGColor);

    CGContextMoveToPoint(ref, 150, 150);

    CGContextAddArc(ref, 150, 150, 100, 100*M_PI /180, 260*M_PI /180, 0);

    CGContextFillPath(ref);

    

    CGContextSetFillColorWithColor(ref, [UIColor yellowColor].CGColor);

    CGContextMoveToPoint(ref, 150, 150);

    CGContextAddArc(ref, 150, 150,100 , 260*M_PI /180, 360*M_PI /180, 0);

    CGContextFillPath(ref);

    

    //抛物线

    CGContextMoveToPoint(ref, 50, 200);

    CGContextAddQuadCurveToPoint(ref, 100, 400, 150, 200);

    CGContextStrokePath(ref);

    //Core Graphics/OpenGL ES  绘图系统

}

//矩形

-(void)drawRecttang{

    

//得到上下文

    CGContextRef ref = UIGraphicsGetCurrentContext();

    //<#CGFloat blur#> 最后一个参数代表的是阴影的羽化程度

    //CGContextSetShadow(ref, CGSizeMake(30, 30), 20);

    CGContextSetShadowWithColor(ref, CGSizeMake(30, 30), 20, [UIColor yellowColor].CGColor);

    

    //填充颜色

    CGContextSetFillColorWithColor(ref, [UIColor magentaColor].CGColor);

    //矩形

    CGContextAddRect(ref, CGRectMake(50, 50, 200, 200));

    CGContextAddEllipseInRect(ref, CGRectMake(50, 50, 200, 200));

    

    //只是划线  不能与填充前后执行  执行完前面的之后  命令就停止绘图

    //CGContextStrokePath(ref);

    

    //填充

    //CGContextFillPath(ref);

    

    //同时划线填充

    CGContextDrawPath(ref, kCGPathFillStroke);

}

//线

-(void)drawLine{

    //得到上下文

    CGContextRef ref = UIGraphicsGetCurrentContext();

    //线的颜色

    CGContextSetStrokeColorWithColor(ref, [UIColor magentaColor].CGColor);

    //线宽

    CGContextSetLineWidth(ref, 10);

    //相交时角的样式

    CGContextSetLineJoin(ref, kCGLineJoinRound);

    //画虚线 10 是起始位置

    CGFloat lengths[] = {20,20};//实线 虚线 20  10

    CGContextSetLineDash(ref, 10  , lengths, 2);

    //虚线的地方是圆角

    CGContextSetLineCap(ref, kCGLineCapRound);

    //移动起点  画笔的起点

    CGContextMoveToPoint(ref, 50, 50);

    //添加一条线

    CGContextAddLineToPoint(ref, 250, 50);

    CGContextAddLineToPoint(ref, 150, 250);

    //CGContextAddLineToPoint(ref, 50, 50);

    //封闭图形

    CGContextClosePath(ref);

    //开始划线

    CGContextStrokePath(ref);

    

    

}

//文本

-(void)drawText{

    NSString * str = @"西门吹雪大战叶孤城，陆小凤，花满楼，司空摘星，木道人。";

    [str drawInRect:self.bounds withAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:30.0],NSForegroundColorAttributeName:[UIColor blueColor]}];

}

//图片

-(void)drawImage{

    UIImage * image1 = [UIImage imageNamed:@"5"];

    [image1 drawInRect:self.bounds];

    

    UIImage * image2 = [UIImage imageNamed:@"32_16"];

    //叠加效果

    /*

     kCGBlendModeNormal,

     kCGBlendModeMultiply,

     kCGBlendModeScreen,

     kCGBlendModeOverlay,

     kCGBlendModeDarken,

     kCGBlendModeLighten,

     kCGBlendModeColorDodge,

     kCGBlendModeColorBurn,

     kCGBlendModeSoftLight,

     kCGBlendModeHardLight,

     kCGBlendModeDifference,

     kCGBlendModeExclusion,

     kCGBlendModeHue,

     kCGBlendModeSaturation,

     kCGBlendModeColor,

     kCGBlendModeLuminosity,

     */

    [image2 drawAtPoint:CGPointMake(0, 0) blendMode:kCGBlendModeExclusion alpha:0.5];

}