iOS- 绘图API

1.iOS- 绘图API之绘制线条

<pre name="code" class="objc">////  DrawLineView.m//  DrawLine////  Created by 程磊 on 15/5/5.//  Copyright (c) 2015年 程磊. All rights reserved.//#import "DrawLineView.h"@implementation DrawLineView/** *  重写父类的drawRect方法，此方法是在视图出现时调用 * */- (void)drawRect:(CGRect)rect {    CGContextRef context = UIGraphicsGetCurrentContext();//获取其绘图内容    CGContextMoveToPoint(context, 100, 100);//将画笔移动某一点    CGContextAddLineToPoint(context, 200, 100);//从初始点直线连接到这一点    CGContextAddLineToPoint(context, 200, 200);//继续直线连到某一点            CGContextMoveToPoint(context, 100, 300);//将画笔再移动到另一点    CGContextAddLineToPoint(context, 300, 200);//直线连接到某一点        CGContextSetRGBStrokeColor(context, 1, 0, 1, 1);//设置线条颜色        CGContextSetLineWidth(context, 5);//设置线条粗细        CGContextSetShadow(context, CGSizeMake(10, 10), 10);//设置线条阴影，最后一个参数是模糊度        CGContextStrokePath(context);//进行呈现，将绘制的线条呈现出来}@end

2.iOS- 绘图API之绘制矩形

<span style="font-size:14px;">////  DrawRectView.m//  DrawLine////  Created by 程磊 on 15/5/5.//  Copyright (c) 2015年 程磊. All rights reserved.//#import "DrawRectView.h"@implementation DrawRectView- (id)initWithCoder:(NSCoder *)aDecoder {    return [super initWithCoder:aDecoder];}- (void)drawRect:(CGRect)rect {    CGContextRef context = UIGraphicsGetCurrentContext();//获取当前绘图        CGContextAddRect(context, CGRectMake(100, 100, 100, 100));//添加矩形坐标        CGContextSetRGBFillColor(context, 1, 0, 0, 1);//设置颜色            CGContextFillPath(context);//填充    //    CGContextStrokeRect(context, CGRectMake(100, 100, 100, 100));//设置边框    //    CGContextSetLineWidth(context, 10);//设置边框宽度        CGContextSetRGBStrokeColor(context, 0, 1, 0, 1);//设置边框颜色        CGContextStrokeRectWithWidth(context, CGRectMake(100, 100, 100, 100), 10);//设置边框及其宽度    }@end</span><span style="font-size: 18px;"></span>

3.iOS- 绘图API之绘制圆形

<span style="font-size:14px;">////  DrawCircleView.m//  DrawLine////  Created by 程磊 on 15/5/6.//  Copyright (c) 2015年 程磊. All rights reserved.//#import "DrawCircleView.h"@implementation DrawCircleView- (id)initWithCoder:(NSCoder *)aDecoder {    return [super initWithCoder:aDecoder];}// An empty implementation adversely affects performance during animation.- (void)drawRect:(CGRect)rect {        CGContextRef context = UIGraphicsGetCurrentContext();        CGContextAddArc(context, 150, 200, 100, 0, 2*M_PI, 0); //圆心坐标、半径，弧度，0顺时针，1逆时针        CGContextSetLineWidth(context, 10);//设置线条粗度            CGContextStrokePath(context);//绘制线条        CGContextAddArc(context, 150, 200, 100, 0, 2*M_PI, 0); //圆心坐标、半径，弧度，0顺时针，1逆时针    CGContextSetRGBFillColor(context, 1, 0, 0, 1);//设置填充颜色    CGContextFillPath(context);//填充色    CGContextAddEllipseInRect(context, CGRectMake(100, 400, 50, 50));//这是在矩形中绘制一个圆，如果是正方形则是圆，否则椭圆        CGContextSetLineWidth(context, 5);        CGContextStrokePath(context);    }@end</span><span style="font-size: 18px;"></span>

4.iOS- 绘图API之绘制图片

<span style="font-size:14px;">////  DrawImageView.m//  DrawLine////  Created by 程磊 on 15/5/6.//  Copyright (c) 2015年 程磊. All rights reserved.//#import "DrawImageView.h"@implementation DrawImageView// Only override drawRect: if you perform custom drawing.// An empty implementation adversely affects performance during animation.- (void)drawRect:(CGRect)rect {        UIImage *image = [UIImage imageNamed:@"20110825172739-14284794.jpg"];        CGContextRef context = UIGraphicsGetCurrentContext();        CGContextSaveGState(context);//保留起始状态        CGContextTranslateCTM(context, 60, 400);//移动图片坐标        CGContextScaleCTM(context, 1, -1);//围绕某一点旋转,因为CGImage与图片坐标相反，所以        CGContextDrawImage(context, CGRectMake(0, 0, 200, 200), image.CGImage);//绘制图片        CGContextRestoreGState(context);//恢复context状态        }@end</span><span style="font-size: 18px;"></span>

5.画板Demo

</pre><pre name="code" class="objc" style="font-size: 18px;">

<span style="font-size:14px;">////  DrawingBoardView.m//  DrawLine////  Created by 程磊 on 15/5/6.//  Copyright (c) 2015年 程磊. All rights reserved.//#import "DrawingBoardView.h"@interface DrawingBoardView ()@property (nonatomic, assign) CGMutablePathRef path;@end@implementation DrawingBoardView// Only override drawRect: if you perform custom drawing.// An empty implementation adversely affects performance during animation.- (void)drawRect:(CGRect)rect {    CGContextRef context = UIGraphicsGetCurrentContext();//获取绘制文本    CGContextAddPath(context, _path);//添加绘制文本以及路径    CGContextStrokePath(context);//绘制}- (void)awakeFromNib{    _path = CGPathCreateMutable();}- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {    UITouch *touch = touches.anyObject;//获取触摸手势    CGPoint p = [touch locationInView:self];//获取触摸点    CGPathMoveToPoint(_path, nil, p.x, p.y);//移动到初识位置点}- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {    UITouch *touch = [touches anyObject];    CGPoint p = [touch locationInView:self];    CGPathAddLineToPoint(_path, nil, p.x, p.y);//将其连线    [self setNeedsDisplay];//只要执行这个方法，系统就会认为你需要重绘，就会调用drawRect:(CGRect)rect}@end</span><span style="font-size: 18px;"></span>