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>