从相册选择完图片后把图片显示在画板上了但是还没有渲染到layer，这时候需要对图片进行移动缩放旋转这些操作的话，但是UIImage是不能拉伸旋转这些操作的，UIImageView才可以，所以解决思路就是自定义一个view来专门处理对图片的操作，在自定义view上放一个UIImageView，从相册选择图片后获取的image设置给UIImageView，这样的自定义view上操作UIIamgeView。
#import <UIKit/UIKit.h>
@interface ImageHandleView : UIView
/** 图片 */
@property(nonatomic, strong) UIImage *image;
/** block */
@property(nonatomic, strong) void(^handleCompletionBlock)(UIImage *image);
@end
#import "ImageHandleView.h"
@interface ImageHandleView () <UIGestureRecognizerDelegate>
/** image */
@property(nonatomic, weak) UIImageView *imageView;
@end
@implementation ImageHandleView
//防止图片上的触摸事件传递到画板
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
return _imageView;
}
- (UIImageView *)imageView {
if (_imageView == nil) {
UIImageView *imageV = [[UIImageView alloc]initWithFrame:self.bounds];
_imageView = imageV;
//设置imgaeview允许与用户交互
_imageView.userInteractionEnabled = YES;
//添加手势
[self setUpGestureRecognizer];
//把这个imageview添加到图片处理的view上
[self addSubview:imageV];
}
return _imageView;
}
#pragma mark - 添加手势
- (void)setUpGestureRecognizer {
//平移手势
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(pan:)];
[_imageView addGestureRecognizer:pan];
//旋转手势
UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc]initWithTarget:self action:@selector(rotation:)];
rotation.delegate = self;
[_imageView addGestureRecognizer:rotation];
//缩放手势
UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinch:)];
pinch.delegate = self;
[_imageView addGestureRecognizer:pinch];
//长按手势
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longPress:)];
[_imageView addGestureRecognizer:longPress];
}
#pragma mark - 处理平移手势
- (void)pan:(UIPanGestureRecognizer *)pan {
//获取手指的偏移量
CGPoint tranp = [pan translationInView:self.imageView];
//设置imageview的形变
self.imageView.transform = CGAffineTransformTranslate(self.imageView.transform, tranp.x, tranp.y);
//复位
[pan setTranslation:CGPointZero inView:self.imageView];
}
#pragma mark - 处理旋转手势
- (void)rotation:(UIRotationGestureRecognizer *)rotation {
//设置imageview的形变
self.imageView.transform = CGAffineTransformRotate(self.imageView.transform, rotation.rotation);
//复位
rotation.rotation = 0;
}
#pragma mark - 处理缩放手势
- (void)pinch:(UIPinchGestureRecognizer *)pinch {
//设置imageview的形变
self.imageView.transform = CGAffineTransformScale(self.imageView.transform, pinch.scale, pinch.scale);
//复位
pinch.scale = 1;
}
#pragma mark - 处理长按手势
- (void)longPress:(UILongPressGestureRecognizer *)longPress {
//图片处理完成
if (longPress.state == UIGestureRecognizerStateBegan) {
//高亮效果
[UIView animateWithDuration:0.25 animations:^{
self.imageView.alpha = 0;
} completion:^(BOOL finished) {
[UIView animateWithDuration:0.25 animations:^{
self.imageView.alpha = 1;
} completion:^(BOOL finished) {
//高亮时生成一张新的图片
//开启位图上下文
UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, 0);
//获取位图上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();
//把控件的图层渲染到上下文
[self.layer renderInContext:ctx];
//从上下文中获取新的图片
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
//关闭上下文
UIGraphicsEndImageContext();
//调用block
if(_handleCompletionBlock) {
_handleCompletionBlock(image);
}
//移除父控件
[self removeFromSuperview];
}];
}];
}
}
#pragma mark - 手势代理方法 <UIGestureRecognizerDelegate>
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
//yes表示同时支持多个手势
return YES;
}
- (void)setImage:(UIImage *)image {
_image = image;
//把图片展示到UIImageView上
self.imageView.image = image;
}
@end
