UITouch、CGContextRef简单综合应用

#import <UIKit/UIKit.h>

@interface KView:UIView {

//放划线数组

NSMutableArray *array;

//放删除时的线

NSMutableArray *array1;

CGContextRef context;

}

@end

#import "KView.h"

@implementation KView

- (id)initWithFrame:(CGRect)frame

{

self = [super initWithFrame:frame];

if (self) {

// Initialization code

//支持多触点

//self.multipleTouchEnabled=YES;

;

self.backgroundColor=[UIColor whiteColor];

array1=[[NSMutableArray alloc]init];

array=[[NSMutableArray alloc]init];

UIButton* button=[UIButton buttonWithType:UIButtonTypeRoundedRect];

button.frame=CGRectMake(0, 0, 50, 30);

[button setTitle:@"后退" forState:0];

[button addTarget:self

action:@selector(cler)

forControlEvents:UIControlEventTouchUpInside];

[self addSubview:button];

button=[UIButton buttonWithType:UIButtonTypeRoundedRect];

button.frame=CGRectMake(60, 0, 50, 30);

[button setTitle:@"前进" forState:0];

[button addTarget:self

action:@selector(add)

forControlEvents:UIControlEventTouchUpInside];

[self addSubview:button];

button=[UIButton buttonWithType:UIButtonTypeRoundedRect];

button.frame=CGRectMake(120, 0, 50, 30);

[button setTitle:@"清除" forState:0];

[button addTarget:self

action:@selector(allclear)

forControlEvents:UIControlEventTouchUpInside];

[self addSubview:button];

// UITouch *t=[touches anyObject];

// CGPoint p= [t locationInView:self];

// NSLog(@"%@",NSStringFromCGPoint(p));

}

return self;

}

//清除所有线

-(void)allclear{

[array removeAllObjects];

[array1 removeAllObjects];

//重新加载此页面

[self setNeedsDisplay];

}

//清除最后一条划线

-(void)cler{

if (array.count==0) {

[array1 removeAllObjects];

}else{

[array1 addObject:[array lastObject]];

[array removeLastObject];

[self setNeedsDisplay];

}

}

-(void)add{

if (array1.count==0) {

}else{

[array addObject:[array1 lastObject]];

[array1 removeLastObject];

[self setNeedsDisplay];

}

}

-(void)drawRect:(CGRect)rect{

// CGContextRef context = UIGraphicsGetCurrentContext();

//

//

//

// 画一个正方形图形 没有边框

//

// CGContextSetRGBFillColor(context, 0, 0.25, 0, 0.5);

// CGContextFillRect(context, CGRectMake(2, 2, 270, 270));

// CGContextStrokePath(context);

//

//

//

// 写文字

//

// CGContextSetLineWidth(context, 1.0);

// CGContextSetRGBFillColor (context, 1, 1, 1, 1.0);

//

// UIFont *font = [UIFont boldSystemFontOfSize:11.0];

//

// [@"fangyp" drawInRect:CGRectMake(40, 40, 80, 20) withFont:font];

//

//

//

// 画一条线

//

// CGContextSetRGBStrokeColor(context, 0.5, 0.5, 0.5, 0.5);//线条颜色

// CGContextMoveToPoint(context, 20, 20);

// CGContextAddLineToPoint(context, 200,20);

// CGContextStrokePath(context);

//

//

//

// 画正方形边框

//

// CGContextSetRGBStrokeColor(context, 1, 1.0, 1.0, 1.0);

// CGContextSetLineWidth(context, 2.0);

// CGContextAddRect(context, CGRectMake(2, 2, 270, 270));

// CGContextStrokePath(context);

//

//

//

// 画方形背景颜色

// CGContextTranslateCTM(ctx, 0.0f, self.view.bounds.size.height);

// CGContextScaleCTM(ctx, 1.0f, -1.0f);

// UIGraphicsPushContext(ctx);

// CGContextSetLineWidth(ctx,320);

// CGContextSetRGBStrokeColor(ctx, 250.0/255, 250.0/255, 210.0/255, 1.0);

// CGContextStrokeRect(ctx, CGRectMake(0, 0, 320, 460));

//获取当前的画布

CGContextRef con=UIGraphicsGetCurrentContext();

//设置画笔颜色

CGContextSetStrokeColorWithColor(con, [UIColor redColor].CGColor);

//设置画笔宽度

CGContextSetLineWidth(con, 3.0f);

for (int i=0; i<array.count; i++) {

NSMutableArray *ar=[array objectAtIndex:i];

for (int j=0; j<ar.count-1; j++) {

CGPoint point=CGPointFromString([ar objectAtIndex:j]);

//NSLog(@"point.x=%f point.xy=%f",point.x,point.y);

CGPoint point1=CGPointFromString([ar objectAtIndex:j+1]);

//NSLog(@"point1.x=%f point1.y=%f",point1.x,point1.y);

//初识划线起点

CGContextMoveToPoint(con, point.x, point.y);

//划线的终点

CGContextAddLineToPoint(con, point1.x, point1.y);

//将两点链接

CGContextStrokePath(con);

}

}

}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

//NSLog(@"%s",__func__);

//NSLog(@"%@",touches);

UITouch *t=[touches anyObject];

CGPoint p= [t locationInView:self];

NSMutableArray *aNewLine=[[NSMutableArray alloc]init];

[aNewLine addObject:NSStringFromCGPoint(p)];

[array addObject:aNewLine];

[aNewLine release];

// NSLog(@"%@",NSStringFromCGPoint(p));

[self setNeedsDisplay];

}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{

//NSLog(@"%s",__func__);

UITouch *t=[touches anyObject];

CGPoint p= [t locationInView:self];

[[array lastObject]addObject:NSStringFromCGPoint(p)];

//NSLog(@"%@",NSStringFromCGPoint(p));

[self setNeedsDisplay];

}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{

// NSLog(@"%s",__func__);

// for (int i=0; i<array.count; i++) {

// NSLog(@"%d",array.count);

// NSLog(@"%@",[array objectAtIndex:i]);

// }

}

-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{

NSLog(@"%s",__func__);

}

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画一个正方形图形 没有边框

CGContextSetRGBFillColor(context, 0, 0.25, 0, 0.5);

CGContextFillRect(context, CGRectMake(2, 2, 270, 270));

CGContextStrokePath(context);

写文字

CGContextSetLineWidth(context, 1.0);

CGContextSetRGBFillColor (context, 1, 1, 1, 1.0);

UIFont *font = [UIFont boldSystemFontOfSize:11.0];

[@"fangyp" drawInRect:CGRectMake(40, 40, 80, 20) withFont:font];

画一条线

CGContextSetRGBStrokeColor(context, 0.5, 0.5, 0.5, 0.5);//线条颜色

CGContextMoveToPoint(context, 20, 20);

CGContextAddLineToPoint(context, 200,20);

CGContextStrokePath(context);

画正方形边框

CGContextSetRGBStrokeColor(context, 1, 1.0, 1.0, 1.0);

CGContextSetLineWidth(context, 2.0);

CGContextAddRect(context, CGRectMake(2, 2, 270, 270));

CGContextStrokePath(context);

画方形背景颜色

CGContextTranslateCTM(ctx, 0.0f, self.view.bounds.size.height);
CGContextScaleCTM(ctx, 1.0f, -1.0f);
UIGraphicsPushContext(ctx);
CGContextSetLineWidth(ctx,320);
CGContextSetRGBStrokeColor(ctx, 250.0/255, 250.0/255, 210.0/255, 1.0);
CGContextStrokeRect(ctx, CGRectMake(0, 0, 320, 460));

UIGraphicsPopContext();