书法绘图IOS核心 [英] Calligraphy Drawing IOS Coregraphics

问题描述

我想要有一个标记为红色的东西，作为标记，但不知道是否可以做。

它看起来像标记书法笔。

>

尝试以下代码作为回答Andrey，我在绘制时获得以下输出结果。

可以在这里找到画刷图片

进一步更改代码，我发现仍然无法获得预期的结果。
这里我试图填充当前点和下一个点之间存在的路径。

   - ）drawRect：（CGRect）rect 
 {
 //绘图代码
 
 
 CGFloat w = 5.0; 
 CGFloat h = 2.0; 
 CGContextRef context = UIGraphicsGetCurrentContext（）; 
 CGContextSetFillColorWithColor（context，[UIColor redColor] .CGColor）; 
 
 for（int i = 0; i< self.positions.count; i ++）{
 CGPoint point = [[self.positions objectAtIndex：i] CGPointValue]; 
 
 CGFloat x = point.x-（w / 2.0）; 
 CGFloat y = point.y-（h / 2.0）; 
 CGContextFillRect（context，CGRectMake（x，y，w，h））; 
 if（i + 1< self.positions.count）{
 CGPoint nextPoint = [[self.positions objectAtIndex：（i + 1）] CGPointValue]; 
 CGMutablePathRef myPath = CGPathCreateMutable（）; 
 CGPathMoveToPoint（myPath，NULL，x，y）; 
 CGFloat x1 = nextPoint.x-（w / 2.0）; 
 CGFloat y1 = nextPoint.y-（h / 2.0）; 
 
 CGPathAddLineToPoint（myPath，NULL，x1，y1）; 
 CGPathAddLineToPoint（myPath，NULL，w，y1）; 
 CGPathAddLineToPoint（myPath，NULL，w，y）; 
 CGPathCloseSubpath（myPath）; 
 CGContextFillPath（context）; 
} 
} 
} 
  

解决方案>

这些图片可以通过在 UIView 子类中重写 drawRect：消息来绘制图片。你还需要添加一些触摸处理程序来捕捉触摸。所以这里是一些代码：

  @interface DrawingView（）
 
 @property（nonatomic，strong） NSMutableArray * positions; 
 
 @end 
 
 @implementation DrawingView 
 
  - （id）initWithFrame：（CGRect）frame 
 {
 self = [super initWithFrame：frame]; 
 if（self）{
 [self awakeFromNib]; 
} 
 return self; 
} 
 
  - （void）awakeFromNib 
 {
 self.positions = [[NSMutableArray alloc] init]; 
} 
 
  - （void）drawRect：（CGRect）rect 
 {
 [super drawRect：rect]; 
 
 UIImage * brushImage = [UIImage imageNamed：@brush.png]; 
 for（NSValue * object in self.positions）{
 CGPoint point = [object CGPointValue]; 
 [brushImage drawAtPoint：CGPointMake（point.x  -  brushImage.size.width / 2.0，point.y  -  brushImage.size.height / 2.0）]; 
} 
} 
 
  - （void）addPoint：（CGPoint）point 
 {
 [self.positions addObject：[NSValue valueWithCGPoint：point] ; 
 
 [self setNeedsDisplay]; 
} 
 
  - （void）touchesBegan：（NSSet *）touches withEvent：（UIEvent *）event 
 {
 UITouch * touch = [touches anyObject]; 
 [self addPoint：[touch locationInView：self]]; 
} 
 
  - （void）touchesMoved：（NSSet *）touches withEvent：（UIEvent *）event 
 {
 UITouch * touch = [touches anyObject]; 
 [self addPoint：[touch locationInView：self]]; 
} 
 
  - （void）touchesEnded：（NSSet *）touches withEvent：（UIEvent *）event 
 {
 UITouch * touch = [touches anyObject]; 
 [self addPoint：[touch locationInView：self]]; 
} 
 
 @end 
  

您只需创建 brush.png ，并将这些视图放在任何你想要的地方。

I am looking to have something which is marked in red, as marker but don't know whether it can be done or not.

It looks like marking using a calligraphy pen.

Trying out the following code as answered by "Andrey", I get the following output with spaces while drawing.

Brush image can be found here used is

Making further changes to the code, I found still I am not able to get the expected result. Here I am trying to fill the path which exists between the current point and the next point.

- (void)drawRect:(CGRect)rect
{
    // Drawing code


    CGFloat w=5.0;
    CGFloat h=2.0;
    CGContextRef context=UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);

    for(int i=0;i<self.positions.count;i++){
        CGPoint point=[[self.positions objectAtIndex:i] CGPointValue];

        CGFloat x=point.x-(w/2.0);
        CGFloat y=point.y-(h/2.0);
        CGContextFillRect(context, CGRectMake(x, y, w, h));
        if(i+1<self.positions.count){
            CGPoint nextPoint=[[self.positions objectAtIndex:(i+1)] CGPointValue];
            CGMutablePathRef myPath=CGPathCreateMutable();
            CGPathMoveToPoint(myPath, NULL, x, y);
            CGFloat x1=nextPoint.x-(w/2.0);
            CGFloat y1=nextPoint.y-(h/2.0);

            CGPathAddLineToPoint(myPath, NULL, x1, y1);
            CGPathAddLineToPoint(myPath, NULL, w, y1);
            CGPathAddLineToPoint(myPath, NULL, w, y);
            CGPathCloseSubpath(myPath);
            CGContextFillPath(context);
        }
    }
}

解决方案

Those picture can be done via drawing an image in UIView subclass with overridden drawRect: message. You also need to add some kind of touch handler for catching touches. So here is some code:

@interface DrawingView ()

@property (nonatomic, strong) NSMutableArray *positions;

@end

@implementation DrawingView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self awakeFromNib];
    }
    return self;
}

- (void)awakeFromNib
{
    self.positions = [[NSMutableArray alloc] init];
}

- (void)drawRect:(CGRect)rect
{
    [super drawRect:rect];

    UIImage *brushImage = [UIImage imageNamed:@"brush.png"];
    for (NSValue *object in self.positions) {
        CGPoint point = [object CGPointValue];
        [brushImage drawAtPoint:CGPointMake(point.x - brushImage.size.width / 2.0, point.y - brushImage.size.height / 2.0)];
    }
}

- (void)addPoint:(CGPoint)point
{
    [self.positions addObject:[NSValue valueWithCGPoint:point]];

    [self setNeedsDisplay];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    [self addPoint:[touch locationInView:self]];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    [self addPoint:[touch locationInView:self]];
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    [self addPoint:[touch locationInView:self]];
}

@end

You only need to create a proper brush.png and place those view anywhere you want.

这篇关于书法绘图IOS核心的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！