封装上下文
UIImage (CaptureView).h / .m
@interface UIImage (CaptureView) + (UIImage *)captureImageWithView:(UIView *)view;
@end
#import "UIImage+captureView.h" @implementation UIImage (CaptureView) + (UIImage *)captureImageWithView:(UIView *)view
{
// 1.创建bitmap上下文
UIGraphicsBeginImageContext(view.frame.size);
// 2.将要保存的view的layer绘制到bitmap上下文中
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
// 3.取出绘制号的图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
return newImage;
} @end
画画板
NJView.h / .m
@interface NJView : UIView - (void)clearView;
- (void)backView;
@end
#import "NJView.h" @interface NJView () @property (nonatomic, strong) NSMutableArray *paths; @end @implementation NJView - (NSMutableArray *)paths
{
if (_paths == nil) {
_paths = [NSMutableArray array];
}
return _paths;
} // 开始触摸
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{ // 1.获取手指对应UITouch对象
UITouch *touch = [touches anyObject];
// 2.通过UITouch对象获取手指触摸的位置
CGPoint startPoint = [touch locationInView:touch.view]; // 3.当用户手指按下的时候创建一条路径
UIBezierPath *path = [UIBezierPath bezierPath];
// 3.1设置路径的相关属性
[path setLineJoinStyle:kCGLineJoinRound];
[path setLineCapStyle:kCGLineCapRound];
[path setLineWidth:]; // 4.设置当前路径的起点
[path moveToPoint:startPoint];
// 5.将路径添加到数组中
[self.paths addObject:path]; }
// 移动
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
// 1.获取手指对应UITouch对象
UITouch *touch = [touches anyObject];
// 2.通过UITouch对象获取手指触摸的位置
CGPoint movePoint = [touch locationInView:touch.view]; // 3.取出当前的path
UIBezierPath *currentPaht = [self.paths lastObject];
// 4.设置当前路径的终点
[currentPaht addLineToPoint:movePoint]; // 6.调用drawRect方法重回视图
[self setNeedsDisplay]; } // 离开view(停止触摸)
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{ [self touchesMoved:touches withEvent:event];
/*
// 1.获取手指对应UITouch对象
UITouch *touch = [touches anyObject];
// 2.通过UITouch对象获取手指触摸的位置
CGPoint endPoint = [touch locationInView:touch.view]; // 3.取出当前的path
UIBezierPath *currentPaht = [self.paths lastObject];
// 4.设置当前路径的终点
[currentPaht addLineToPoint:endPoint]; // 6.调用drawRect方法重回视图
[self setNeedsDisplay];
*/ } // 画线
- (void)drawRect:(CGRect)rect
{ [[UIColor redColor] set];
// 边路数组绘制所有的线段
for (UIBezierPath *path in self.paths) {
[path stroke];
} } - (void)test
{
/*
// 1.创建一条路径
CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, 20, 20);
CGPathAddLineToPoint(path, NULL, 100, 100); CGMutablePathRef path2 = CGPathCreateMutable();
CGPathMoveToPoint(path2, NULL, 120, 120);
CGPathAddLineToPoint(path2, NULL, 200, 200); CGContextRef ctx = UIGraphicsGetCurrentContext();
// 2.将路径添加到上下文中
CGContextAddPath(ctx, path);
CGContextAddPath(ctx, path2); // 3.渲染
CGContextStrokePath(ctx);
*/ /*
// UIBezierPath == CGMutablePathRef // 1.创建一条路径
UIBezierPath *path = [UIBezierPath bezierPath];
// 2.给路径设置起点和重点
[path moveToPoint:CGPointMake(20, 20)];
[path addLineToPoint:CGPointMake(100, 100)]; [path setLineCapStyle:kCGLineCapRound];
[path setLineWidth:10];
[path setLineJoinStyle:kCGLineJoinRound]; // 3.渲染路径
[path stroke]; // 1.创建一条路径
UIBezierPath *path2 = [UIBezierPath bezierPath];
// 2.给路径设置起点和重点
[path2 moveToPoint:CGPointMake(120, 120)];
[path2 addLineToPoint:CGPointMake(200, 200)]; [path2 stroke];
*/
} - (void)clearView
{
[self.paths removeAllObjects];
[self setNeedsDisplay];
}
- (void)backView
{
[self.paths removeLastObject];
[self setNeedsDisplay];
}
调用画画板到控制器
@interface NJViewController ()
/**
* 清屏
*/
- (IBAction)clearBtnClick;
/**
* 回退
*/
- (IBAction)backBtnClick;
/**
* 保存
*/
- (IBAction)saveBtnClick; @property (weak, nonatomic) IBOutlet NJView *customView;
@end @implementation NJViewController
- (IBAction)clearBtnClick {
[self.customView clearView];
} - (IBAction)backBtnClick { [self.customView backView];
} - (IBAction)saveBtnClick { UIImage *newImage = [UIImage captureImageWithView:self.customView];
// 4.保存到相册
UIImageWriteToSavedPhotosAlbum(newImage, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
} - (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
if (error) {
[MBProgressHUD showError:@"保存失败"];
}else
{
[MBProgressHUD showSuccess:@"保存成功"];
}
}
@end