如何绘制一个矩形
添加一个属性
@property(nonatomic,strong) NSString* RectNumber;
1. 首先重写UIview的drawRect方法
- (void)drawRect:(CGRect)rect {
CGContextRef ctx = UIGraphicsGetCurrentContext();
int number = [self.RectNumber intValue];
int x = 50;
int y = 0;
CGContextBeginPath(ctx);
//设置图形间距
for (int i=0; i<number; i++) {
if (i%3 == 0) {
y+=100;
x=50;
}
[self AddRect:ctx leftPoint:x rightPoint:y width:90 height:50];
x+=100;
}
CGContextSetRGBStrokeColor(ctx, 0.5, 0, 0, 1);
CGContextSetRGBFillColor(ctx, 0, 1, 0, 1);
CGContextDrawPath(ctx, kCGPathEOFillStroke);
//打开路径
CGContextStrokePath(ctx);
//关闭路径
CGContextClosePath(ctx);
}
2. 实现自定义方法
-(void)AddRect:(CGContextRef)r leftPoint:(CGFloat)x1 rightPoint:(CGFloat)x2 width:(CGFloat)w height:(CGFloat)h
{
CGContextMoveToPoint(r, x1, x2);
//添加一条连接到右上角的线
CGContextAddLineToPoint(r, x1+w, x2);
//添加一条连接到右下角的先
CGContextAddLineToPoint(r, x1+w, x2+h);
//添加一条连接到左下角的线
CGContextAddLineToPoint(r, x1, x2+h);
//添加一条连接到左上角的线
CGContextAddLineToPoint(r, x1, x2);
}
3添加一个生成按钮
field2 = [[UITextField alloc]initWithFrame:CGRectMake(50, 150, 200, 40)];
field2.placeholder = @"输入要多少个矩形";
[self.view addSubview:field2];
btn2 = [UIButton buttonWithType:UIButtonTypeCustom];
btn2.frame = CGRectMake(100, 200, 80, 40);
[btn2 setTitle:@"生成" forState:UIControlStateNormal];
[btn2 setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
[btn2 addTarget:self action:@selector(click3) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn2];
self.view.backgroundColor = [UIColor whiteColor];
4 viewController 里实现生产方法
curRect = [[CurRectView alloc]initWithFrame:self.view.frame];
curRect.backgroundColor = [UIColor whiteColor];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(click4)];
[curRect addGestureRecognizer:tap];
curRect.RectNumber = field2.text;
[self.view addSubview:curRect];
5 手势移除视图
[curRect removeFromSuperview];
如何绘制五角星
添加一个属性
@property (nonatomic,strong) NSString *starNumber;
1. 首先重写UIview的drawRect方法
-(void)drawRect:(CGRect)rect
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
int number = [self.starNumber intValue];
int x = 50;
int y = 0;
CGContextBeginPath(ctx);
//设置图像间距
for (int i=0; i<number; i++) {
if (i%4 == 0) {
y+=100;
x=50;
}
[self CGContextAddStar:ctx starCount:5 starX:x starY:y starSize:50];
x+=100;
}
//图形边框颜色
CGContextSetRGBStrokeColor(ctx, 0, 1, 0, 1);
//设置填充颜色
CGContextSetRGBFillColor(ctx, 1, 0, 0, 1);
CGContextDrawPath(ctx, kCGPathEOFillStroke);
//打开路径
CGContextStrokePath(ctx);
//关闭路径
CGContextClosePath(ctx);
}
2. 实现自定义方法
-(void)CGContextAddStar:(CGContextRef)c starCount:(NSInteger)n starX:(CGFloat)dx starY:(CGFloat)yx starSize:(NSInteger)size
{
//m_pi 是圆周率
CGFloat dig = 4*M_PI/n;
//移动到制定点
CGContextMoveToPoint(c, dx, yx+size);
for (int i = 1; i<=n; i++) {
CGFloat x = sin(i*dig);
CGFloat y = cos(i*dig);
//绘制从当前点到制定点的线条
CGContextAddLineToPoint(c, x*size+dx, y*size+yx);
}
}
3添加一个生成按钮
field1 = [[UITextField alloc]initWithFrame:CGRectMake(50, 50, 200, 40)];
field1.placeholder = @"输入要多少个五角星";
[self.view addSubview:field1];
btn1 = [UIButton buttonWithType:UIButtonTypeCustom];
btn1.frame = CGRectMake(100, 100, 80, 40);
[btn1 setTitle:@"生成" forState:UIControlStateNormal];
[btn1 setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
[btn1 addTarget:self action:@selector(click1) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn1];
self.view.backgroundColor = [UIColor whiteColor];
4 viewController 里实现生产方法
cur = [[CurView alloc]initWithFrame:self.view.frame];
cur.backgroundColor = [UIColor whiteColor];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(click2)];
[cur addGestureRecognizer:tap];
cur.starNumber = field1.text;
[self.view addSubview:cur];
5 手势移除视图
[cur removeFromSuperview];
注 :viewcontroller 里添加全局变量
UITextField *field1,*field2;
UIButton *btn1,*btn2;
CurView *cur;
CurRectView *curRect;