拷贝被人的drawRect绘图分类用途，用法很全。留着、供用时参考
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
/*NO.1画一条线
CGContextSetRGBStrokeColor(context, 0.5, 0.5, 0.5, 0.5);//线条颜色
CGContextMoveToPoint(context, 20, 20);
CGContextAddLineToPoint(context, 200,20);
CGContextStrokePath(context);
*/
/*NO.2写文字
CGContextSetLineWidth(context, 1.0);
CGContextSetRGBFillColor (context, 0.5, 0.5, 0.5, 0.5);
UIFont *font = [UIFont boldSystemFontOfSize:18.0];
[@"公司：北京中软科技股份有限公司 部门：ERP事业部 姓名：McLiang" drawInRect:CGRectMake(20, 40, 280, 300) withFont:font];
*/
/*NO.3画一个正方形图形 没有边框
CGContextSetRGBFillColor(context, 0, 0.25, 0, 0.5);
CGContextFillRect(context, CGRectMake(2, 2, 270, 270));
CGContextStrokePath(context);
*/
/*NO.4画正方形边框
CGContextSetRGBStrokeColor(context, 0.5, 0.5, 0.5, 0.5);//线条颜色
CGContextSetLineWidth(context, 2.0);
CGContextAddRect(context, CGRectMake(2, 2, 270, 270));
CGContextStrokePath(context);
*/
/*NO.5画方形背景颜色
CGContextTranslateCTM(context, 0.0f, self.bounds.size.height);
CGContextScaleCTM(context, 1.0f, -1.0f);
UIGraphicsPushContext(context);
CGContextSetLineWidth(context,320);
CGContextSetRGBStrokeColor(context, 250.0/255, 250.0/255, 210.0/255, 1.0);
CGContextStrokeRect(context, CGRectMake(0, 0, 320, 460));
UIGraphicsPopContext();
*/
/*NO.6椭圆
CGRect aRect= CGRectMake(80, 80, 160, 100);
CGContextSetRGBStrokeColor(context, 0.6, 0.9, 0, 1.0);
CGContextSetLineWidth(context, 3.0);
CGContextAddEllipseInRect(context, aRect); //椭圆
CGContextDrawPath(context, kCGPathStroke);
*/
/*NO.7
CGContextBeginPath(context);
CGContextSetRGBStrokeColor(context, 0, 0, 1, 1);
CGContextMoveToPoint(context, 100, 100);
CGContextAddArcToPoint(context, 50, 100, 50, 150, 50);
CGContextStrokePath(context);
*/
/*NO.8渐变
CGContextClip(context);
CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();
CGFloat colors[] =
{
204.0 / 255.0, 224.0 / 255.0, 244.0 / 255.0, 1.00,
29.0 / 255.0, 156.0 / 255.0, 215.0 / 255.0, 1.00,
0.0 / 255.0, 50.0 / 255.0, 126.0 / 255.0, 1.00,
};
CGGradientRef gradient = CGGradientCreateWithColorComponents
(rgb, colors, NULL, sizeof(colors)/(sizeof(colors[0])*4));
CGColorSpaceRelease(rgb);
CGContextDrawLinearGradient(context, gradient,CGPointMake
(0.0,0.0) ,CGPointMake(0.0,self.frame.size.height),
kCGGradientDrawsBeforeStartLocation);
*/
/* NO.9四条线画一个正方形
//画线
UIColor *aColor = [UIColor colorWithRed:0 green:1.0 blue:0 alpha:0];
CGContextSetRGBStrokeColor(context, 1.0, 0, 0, 1.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
CGContextSetLineWidth(context, 4.0);
CGPoint aPoints[5];
aPoints[0] =CGPointMake(60, 60);
aPoints[1] =CGPointMake(260, 60);
aPoints[2] =CGPointMake(260, 300);
aPoints[3] =CGPointMake(60, 300);
aPoints[4] =CGPointMake(60, 60);
CGContextAddLines(context, aPoints, 5);
CGContextDrawPath(context, kCGPathStroke); //开始画线
*/
/* NO.10
UIColor *aColor = [UIColor colorWithRed:0 green:1.0 blue:0 alpha:0];
CGContextSetRGBStrokeColor(context, 1.0, 0, 0, 1.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
//椭圆
CGRect aRect= CGRectMake(80, 80, 160, 100);
CGContextSetRGBStrokeColor(context, 0.6, 0.9, 0, 1.0);
CGContextSetLineWidth(context, 3.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
CGContextAddRect(context, rect); //矩形
CGContextAddEllipseInRect(context, aRect); //椭圆
CGContextDrawPath(context, kCGPathStroke);
*/
/* NO.11
画一个实心的圆
CGContextFillEllipseInRect(context, CGRectMake(95, 95, 100.0, 100));
*/
/*NO.12
画一个菱形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 150, 150);
CGContextAddLineToPoint(context, 100, 200);
CGContextAddLineToPoint(context, 50, 150);
CGContextAddLineToPoint(context, 100, 100);
CGContextStrokePath(context);
*/
/*NO.13 画矩形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddRect(context, rectangle);
CGContextStrokePath(context);
*/
/*椭圆
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddEllipseInRect(context, rectangle);
CGContextStrokePath(context);
*/
/*用红色填充了一段路径:
CGContextMoveToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 150, 150);
CGContextAddLineToPoint(context, 100, 200);
CGContextAddLineToPoint(context, 50, 150);
CGContextAddLineToPoint(context, 100, 100);
CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
CGContextFillPath(context);
*/
/*填充一个蓝色边的红色矩形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddRect(context, rectangle);
CGContextStrokePath(context);
CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
CGContextFillRect(context, rectangle);
*/
/*画弧
//弧线的是通过指定两个切点，还有角度，调用CGContextAddArcToPoint()绘制
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 100, 100);
CGContextAddArcToPoint(context, 100,200, 300,200, 100);
CGContextStrokePath(context);
*/
/*
绘制贝兹曲线
//贝兹曲线是通过移动一个起始点，然后通过两个控制点,还有一个中止点，调用CGContextAddCurveToPoint() 函数绘制
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 10, 10);
CGContextAddCurveToPoint(context, 0, 50, 300, 250, 300, 400);
CGContextStrokePath(context);
*/
/*绘制二次贝兹曲线
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 10, 200);
CGContextAddQuadCurveToPoint(context, 150, 10, 300, 200);
CGContextStrokePath(context);
*/
/*绘制虚线
CGContextSetLineWidth(context, 5.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGFloat dashArray[] = {2,6,4,2};
CGContextSetLineDash(context, 3, dashArray, 4);//跳过3个再画虚线，所以刚开始有6-（3-2）=5个虚点
CGContextMoveToPoint(context, 10, 200);
CGContextAddQuadCurveToPoint(context, 150, 10, 300, 200);
CGContextStrokePath(context);
*/
/*绘制图片
NSString* imagePath = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage* myImageObj = [[UIImage alloc] initWithContentsOfFile:imagePath];
//[myImageObj drawAtPoint:CGPointMake(0, 0)];
[myImageObj drawInRect:CGRectMake(0, 0, 320, 480)];
NSString *s = @"我的小狗";
[s drawAtPoint:CGPointMake(100, 0) withFont:[UIFont systemFontOfSize:34.0]];
*/
/*
NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);
*/
/*NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGContextRotateCTM(context, M_PI);
CGContextTranslateCTM(context, -img.size.width, -img.size.height);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);*/
/*
NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGAffineTransform myAffine = CGAffineTransformMakeRotation(M_PI);
myAffine = CGAffineTransformTranslate(myAffine, -img.size.width, -img.size.height);
CGContextConcatCTM(context, myAffine);
CGContextRotateCTM(context, M_PI);
CGContextTranslateCTM(context, -img.size.width, -img.size.height);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);
*/
}