UIBezierPath 简介:
使用UIBezierPath类可以创建基于矢量的路径。此类是Core Graphics框架关于path的一个封装。使用此类可以定义简单的形状，如椭圆或者矩形，或者有多个直线和曲线段组成的形状。
1.Bezier Path 基础
UIBezierPath对象是CGPathRef数据类型的封装。path如果是基于矢量形状的，都用直线和曲线段去创建。我们使用直线段去创建矩形和多边形，使用曲线段去创建弧（arc），圆或者其他复杂的曲线形状。每一段都包括一个或者多个点，绘图命令定义如何去诠释这些点。每一个直线段或者曲线段的结束的地方是下一个的开始的地方。每一个连接的直线或者曲线段的集合成为subpath。一个UIBezierPath对象定义一个完整的路径包括一个或者多个subpaths。
创建和使用一个path对象的过程是分开的。创建path是第一步，包含一下步骤：
-
创建一个path对象。
-
使用方法
moveToPoint:去设置初始线段的起点。 -
添加line或者curve去定义一个或者多个subpaths。
-
改变
UIBezierPath对象跟绘图相关的属性。例如，我们可以设置stroked path的属性lineWidth和lineJoinStyle。也可以设置filled path的属性usesEvenOddFillRule。当创建path，我们应该管理path上面的点相对于原点（0，0），这样我们在随后就可以很容易的移动path了。为了绘制path对象，我们要用到stroke和fill方法。这些方法在
current graphic context下渲染path的line和curve段。
2.在path下面添加线或者多边形。
线和多边形是一些简单的形状，我们可以用moveToPoint:或者addLineToPoint:方法去构建。方法moveToPoint:设置我们想要创建形状的起点。从这点开始，我们可以用方法addLineToPoint:去创建一个形状的线段。我们可以连续的创建line，每一个line的起点都是先前的终点，终点就是指定的点。
逻辑构造： DLPaintView: 画板 DLDrawShape: 工具
我这里只实现了3中工具 矩形 椭圆 线 线宽 颜色, 还有很多的工具大家可以自己加了试一下。 按照官方的注释。
DLPaint.h
#import "DLDarwShape.h"
//! @abstract DLPaint View
@interface DLPaintView : UIView
//! @abstract Shape Array With Shape objects
/*!
* Add New Shape Object When Touch begin, Change ShapeObject.bezierPath.
*/
@property (nonatomic, strong) NSMutableArray *allShape;
//! @abstract Darw Shape type
@property (nonatomic, assign) DLPaintShapeType dType;
//! @abstract Darw Line Width
@property (nonatomic, assign) CGFloat lineWidth;
//! @abstract Draw Linw Color
@property (nonatomic, strong) UIColor * drawColor;
/*!
* un do last step
*/
- (void)backout;
/*!
* clean white board
*/
- (void)cleanBoard;
@end
DLPaintView.m
#import "DLPaintView.h"
#import "DLDarwShape.h"
@implementation DLPaintView
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
[self DefaultInit];
}
return self;
}
- (void)awakeFromNib {
[self DefaultInit];
}
- (void)DefaultInit {
_dType = DLPAINT_LINE;
_lineWidth = 2;
_drawColor = [UIColor blackColor];
}
// - //
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
CGPoint startPoint = [[touches anyObject] locationInView:self];
DLDarwShape * shape = [[DLDarwShape alloc] initWithStartPoint:startPoint paintType:_dType color:_drawColor lineWidth:_lineWidth];
[_allShape addObject:shape];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
CGPoint currentPoint = [[touches anyObject] locationInView:self];
[DLDrawPointHandle OperateShapeAction:_allShape.lastObject currentPoint:currentPoint];
[self setNeedsDisplay];
}
// - //
- (void)drawRect:(CGRect)rect {
[self.allShape enumerateObjectsUsingBlock:^(DLDarwShape * ShapeObject, NSUInteger idx, BOOL *stop) {
[ShapeObject Draw];
}];
}
- (void)backout {
[self.allShape removeLastObject];
[self setNeedsDisplay];
}
- (void)cleanBoard {
[self.allShape removeAllObjects];
[self setNeedsDisplay];
}
- (NSMutableArray *)allShape {
if (!_allShape) {
_allShape = [NSMutableArray array];
}
return _allShape;
}
@end
DLDrawShape:
.h
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
typedef NS_OPTIONS(NSUInteger, DLPaintShapeType){
DLPAINT_LINE = 1UL << 0,
DLPAINT_RECT = 1UL << 1,
DLPAINT_OVAL = 1UL << 2
};
//! @abstract Shape Base Object
@interface DLDarwShape : NSObject
//! @abstract stroke Color for shape obejct
@property (nonatomic, strong) UIColor *strokeColor;
//! @abstract Stroke width for shape object
@property (nonatomic, assign) CGFloat strokewidth;
//! @abstract Shape Start point
@property (nonatomic, assign) CGPoint startPoint;
//! @abstract The bezier
@property (nonatomic, retain) UIBezierPath *bezierPath;
//! @abstract Type
@property (nonatomic, assign) DLPaintShapeType paintType;
//! @abstract path array
@property (nonatomic, strong) NSMutableArray * pathArray;
/*!
* Load Shape With start point and type
*
* @param start touch begin Point
* @param pType shape type
* @param color shape object . bezierPath strokeColor
* @param lineWidth shape object . bezierPath strokewidth
*
* @return instance for shape object
*/
- (instancetype)initWithStartPoint: (CGPoint)start
paintType: (DLPaintShapeType)pType
color: (UIColor *)color
lineWidth: (CGFloat)strokeWidth;
/*!
* Draw
*/
- (void)Draw;
@end
@interface DLDrawPointHandle : NSObject
/*!
* Handle Shape Object Action
*
* @param shape Shape Object
* @param cuPoint current point, When Touch moved
*/
+ (void)OperateShapeAction: (DLDarwShape *)shape currentPoint: (CGPoint)cuPoint;
@end
.m
#import "DLDarwShape.h"
@implementation DLDarwShape
- (instancetype)initWithStartPoint: (CGPoint)start
paintType: (DLPaintShapeType)pType
color: (UIColor *)color
lineWidth: (CGFloat)strokeWidth {
self = [super init];
if (self) {
_startPoint = start;
_paintType = pType;
_strokeColor = color;
_strokewidth = strokeWidth;
_bezierPath = [UIBezierPath bezierPath];
[_bezierPath setLineJoinStyle:kCGLineJoinRound];
[_bezierPath setLineCapStyle:kCGLineCapRound];
[_bezierPath moveToPoint:_startPoint];
}
return self;
}
- (NSMutableArray *)pathArray {
if (!_pathArray) {
_pathArray = [NSMutableArray array];
}
return _pathArray;
}
- (void)Draw {
[_strokeColor setStroke];
_bezierPath.lineWidth = _strokewidth;
[_bezierPath stroke];
}
@end
@implementation DLDrawPointHandle
+ (void)OperateShapeAction:(DLDarwShape *)shape currentPoint:(CGPoint)cuPoint {
switch (shape.paintType) {
case DLPAINT_LINE:
[shape.bezierPath addLineToPoint:cuPoint];
break;
case DLPAINT_OVAL:
shape.bezierPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(shape.startPoint.x, shape.startPoint.y, cuPoint.x - shape.startPoint.x, cuPoint.y - shape.startPoint.y)];
break;
case DLPAINT_RECT:
shape.bezierPath = [UIBezierPath bezierPathWithRect:CGRectMake(shape.startPoint.x, shape.startPoint.y, cuPoint.x - shape.startPoint.x, cuPoint.y - shape.startPoint.y)];
break;
default:
break;
}
[shape.pathArray addObject:[NSValue valueWithCGPoint:cuPoint]];
}
@end
效果：
copyRight@Wild Dylan. 2015-6-18