5、画图
（1）画线
//绘图代码写在drawRect里，view加载完成，需要显示的时候调用
//1、获取图形上下文 2、创建路径 3、把图形放入上下文 4、渲染上下文
//drawRect的rect是绘制View的bounds
//重绘
[self setNeedsDisplay];
set = setStroke(描边) + setFill(填充)
//方法一：最原始的方法
//1、获取图形上下文,CG,CoreGraphics,有关图形的框架，开发mac也可以用
CGContextRef ctx = UIGraphicsGetCurrentContext();
//2、创建路径
CGMutablePathRef path = CGPathCreateMutable();
//设置起始点
CGPathMoveToPoint(path, NULL, 50, 50);
//画线到某一点
CGPathAddLineToPoint(path, NULL, 200, 200);
//3、把图形放入上下文
CGContextAddPath(ctx, path);
//4、渲染上下文
CGContextStrokePath(ctx);
//绘图的第二种方法
- (void)drawLine2 {
CGContextRef ctx = UIGraphicsGetCurrentContext();
//设置起始点
CGContextMoveToPoint(ctx, 50, 50);
//画线并设置终点
CGContextAddLineToPoint(ctx, 200, 200);
//渲染上下文
CGContextStrokePath(ctx);
}
//第三种方法
- (void)drawLine3 {
//贝塞尔线,UIKit
//创建路径
UIBezierPath * path = [UIBezierPath bezierPath];
//设置起点
[path moveToPoint:CGPointMake(50, 50)];
//画线并设置终点
[path addLineToPoint:CGPointMake(200, 200)];
//绘制路径
[path stroke];
}
//属性
- (void)drawCtxState {
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextMoveToPoint(ctx, 50, 50);
CGContextAddLineToPoint(ctx, 100, 50);
// CGContextMoveToPoint(ctx, 80, 60);
//默认下一根线的起点就是上一根线的终点
CGContextAddLineToPoint(ctx, 100, 200);
//设置线宽度
CGContextSetLineWidth(ctx, 5);
//设置连接样式
CGContextSetLineJoin(ctx, kCGLineJoinRound);
//设置顶角样式
CGContextSetLineCap(ctx, kCGLineCapRound);
//设置线的颜色
[[UIColor redColor] setStroke];
CGContextStrokePath(ctx);
}
//画曲线
- (void)drawRect:(CGRect)rect {
// Drawing code
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextMoveToPoint(ctx, 50, 50);
//画曲线 arg1 上下文 arg2,3 控制点x,y arg4,5 终点x,y
CGContextAddQuadCurveToPoint(ctx, 100, 100, 250, 50);
CGContextStrokePath(ctx);
}
（2）画图形
//画矩形
UIBezierPath * path = [UIBezierPath bezierPathWithRect:CGRectMake(20, 20, 200, 200)];
//画圆角矩形
UIBezierPath * path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(20, 20, 200, 200) cornerRadius:100];
//画圆弧
//Center 圆弧中心
//radius 圆弧半径
//startAngle 起始角度
//endAngle 结束角度
//clockwise YES 顺时针 NO 逆时针
CGPoint center = CGPointMake(125, 125);
UIBezierPath * path = [UIBezierPath bezierPathWithArcCenter:center radius:100 startAngle:0 endAngle:M_PI_2 clockwise:NO];
[path addLineToPoint:center];
//封闭路径
[path closePath];
[path stroke];
//要使用setFill，路径一定是封闭的
[[UIColor greenColor] setFill];
[path fill];
//画椭圆
UIBezierPath * path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(20, 50, 200, 100)];
[path stroke];
}
6、绘制图片和文字
（1）绘制图片
- (void)drawPicture {
//图片裁剪，超出部分全部剪掉
UIRectClip(CGRectMake(0, 0, 50, 50));
UIImage * image = [UIImage imageNamed:@"01"];
//根据rect拉伸图片
[image drawInRect:CGRectMake(0, 0, 100, 100)];
[image drawInRect:rect];
//显示原图片尺寸
[image drawAtPoint:CGPointZero];
//平铺绘图
[image drawAsPatternInRect:rect];
}
（2）绘制文字
- (void)drawRect:(CGRect)rect {
// Drawing code
NSString * string = @"hgfdagskjhdcadkhdkjlashkdklhahgfdagskjhdcad";
NSShadow * shadow = [[NSShadow alloc] init];
shadow.shadowColor = [UIColor yellowColor];
shadow.shadowOffset = CGSizeMake(5, 5);
//模糊度
shadow.shadowBlurRadius = 3;
NSDictionary * dict = @{NSFontAttributeName:[UIFont systemFontOfSize:30],
NSForegroundColorAttributeName:[UIColor redColor],
NSStrokeColorAttributeName:[UIColor blueColor],
NSStrokeWidthAttributeName:@(2),
NSShadowAttributeName: shadow};
//不会换行
[string drawAtPoint:CGPointZero withAttributes:nil];
[string drawInRect:rect withAttributes:dict];
}
5、画图
（1）画线
//绘图代码写在drawRect里，view加载完成，需要显示的时候调用
//1、获取图形上下文 2、创建路径 3、把图形放入上下文 4、渲染上下文
//drawRect的rect是绘制View的bounds
//重绘
[self setNeedsDisplay];
set = setStroke(描边) + setFill(填充)
//方法一：最原始的方法
//1、获取图形上下文,CG,CoreGraphics,有关图形的框架，开发mac也可以用
CGContextRef ctx = UIGraphicsGetCurrentContext();
//2、创建路径
CGMutablePathRef path = CGPathCreateMutable();
//设置起始点
CGPathMoveToPoint(path, NULL, 50, 50);
//画线到某一点
CGPathAddLineToPoint(path, NULL, 200, 200);
//3、把图形放入上下文
CGContextAddPath(ctx, path);
//4、渲染上下文
CGContextStrokePath(ctx);
//绘图的第二种方法
- (void)drawLine2 {
CGContextRef ctx = UIGraphicsGetCurrentContext();
//设置起始点
CGContextMoveToPoint(ctx, 50, 50);
//画线并设置终点
CGContextAddLineToPoint(ctx, 200, 200);
//渲染上下文
CGContextStrokePath(ctx);
}
//第三种方法
- (void)drawLine3 {
//贝塞尔线,UIKit
//创建路径
UIBezierPath * path = [UIBezierPath bezierPath];
//设置起点
[path moveToPoint:CGPointMake(50, 50)];
//画线并设置终点
[path addLineToPoint:CGPointMake(200, 200)];
//绘制路径
[path stroke];
}
//属性
- (void)drawCtxState {
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextMoveToPoint(ctx, 50, 50);
CGContextAddLineToPoint(ctx, 100, 50);
// CGContextMoveToPoint(ctx, 80, 60);
//默认下一根线的起点就是上一根线的终点
CGContextAddLineToPoint(ctx, 100, 200);
//设置线宽度
CGContextSetLineWidth(ctx, 5);
//设置连接样式
CGContextSetLineJoin(ctx, kCGLineJoinRound);
//设置顶角样式
CGContextSetLineCap(ctx, kCGLineCapRound);
//设置线的颜色
[[UIColor redColor] setStroke];
CGContextStrokePath(ctx);
}
//画曲线
- (void)drawRect:(CGRect)rect {
// Drawing code
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextMoveToPoint(ctx, 50, 50);
//画曲线 arg1 上下文 arg2,3 控制点x,y arg4,5 终点x,y
CGContextAddQuadCurveToPoint(ctx, 100, 100, 250, 50);
CGContextStrokePath(ctx);
}
（2）画图形
//画矩形
UIBezierPath * path = [UIBezierPath bezierPathWithRect:CGRectMake(20, 20, 200, 200)];
//画圆角矩形
UIBezierPath * path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(20, 20, 200, 200) cornerRadius:100];
//画圆弧
//Center 圆弧中心
//radius 圆弧半径
//startAngle 起始角度
//endAngle 结束角度
//clockwise YES 顺时针 NO 逆时针
CGPoint center = CGPointMake(125, 125);
UIBezierPath * path = [UIBezierPath bezierPathWithArcCenter:center radius:100 startAngle:0 endAngle:M_PI_2 clockwise:NO];
[path addLineToPoint:center];
//封闭路径
[path closePath];
[path stroke];
//要使用setFill，路径一定是封闭的
[[UIColor greenColor] setFill];
[path fill];
//画椭圆
UIBezierPath * path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(20, 50, 200, 100)];
[path stroke];
}
6、绘制图片和文字
（1）绘制图片
- (void)drawPicture {
//图片裁剪，超出部分全部剪掉
UIRectClip(CGRectMake(0, 0, 50, 50));
UIImage * image = [UIImage imageNamed:@"01"];
//根据rect拉伸图片
[image drawInRect:CGRectMake(0, 0, 100, 100)];
[image drawInRect:rect];
//显示原图片尺寸
[image drawAtPoint:CGPointZero];
//平铺绘图
[image drawAsPatternInRect:rect];
}
（2）绘制文字
- (void)drawRect:(CGRect)rect {
// Drawing code
NSString * string = @"hgfdagskjhdcadkhdkjlashkdklhahgfdagskjhdcad";
NSShadow * shadow = [[NSShadow alloc] init];
shadow.shadowColor = [UIColor yellowColor];
shadow.shadowOffset = CGSizeMake(5, 5);
//模糊度
shadow.shadowBlurRadius = 3;
NSDictionary * dict = @{NSFontAttributeName:[UIFont systemFontOfSize:30],
NSForegroundColorAttributeName:[UIColor redColor],
NSStrokeColorAttributeName:[UIColor blueColor],
NSStrokeWidthAttributeName:@(2),
NSShadowAttributeName: shadow};
//不会换行
[string drawAtPoint:CGPointZero withAttributes:nil];
[string drawInRect:rect withAttributes:dict];
}
