Fatal编程技术网
  • iphone/
  • Iphone 如何取消擦除的UIImage的擦除？

Iphone 如何取消擦除的UIImage的擦除？

iphone objective-c ios

Iphone 如何取消擦除的UIImage的擦除？,iphone,objective-c,ios,uiimageview,uiimage,Iphone,Objective C,Ios,Uiimageview,Uiimage,我正在我的PanGesture中尝试一个图像擦除代码。我使用的代码如下： UIImage * image = [UIImage imageNamed:@"326d4fb72362a2e44659141cadfc4977.jpg"]; holderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 235)]; imgForeground = [[UIImageView alloc] initWithFr

我正在我的PanGesture中尝试一个图像擦除代码。我使用的代码如下：

 UIImage * image  = [UIImage imageNamed:@"326d4fb72362a2e44659141cadfc4977.jpg"];
 holderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 235)];
 imgForeground = [[UIImageView alloc] initWithFrame:[holderView frame]];
 [imgForeground setImage:image];
 [holderView addSubview:imgForeground];


 UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(move:)];
 [panRecognizer setMinimumNumberOfTouches:1];
 [panRecognizer setMaximumNumberOfTouches:1];
 [panRecognizer setDelegate:self];
 [holderView addGestureRecognizer:panRecognizer];
 [self.view addSubview:holderView];
然后我在这里处理这个问题：

 -(void)move:(id)sender {

    CGPoint currentPoint;
    if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan){
        
        lastPoint =  [sender locationInView:imgForeground];
        lastPoint.y -=20;
    }
    else{
    
        currentPoint = [sender locationInView:imgForeground];;
        currentPoint.y -=20;
    }
   
    
    UIGraphicsBeginImageContext(imgForeground.frame.size);
    [imgForeground.image drawInRect:CGRectMake(imgForeground.frame.origin.x, imgForeground.frame.origin.y, imgForeground.frame.size.width, imgForeground.frame.size.height)];
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetLineCap(context,kCGLineCapRound); //kCGImageAlphaPremultipliedLast);
    CGContextSetLineWidth(context, 10);
    CGContextSetRGBStrokeColor(context, 0, 0, 0, 1.0);
    CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeClear);
    CGContextBeginPath(context);
    CGContextMoveToPoint(context, lastPoint.x, lastPoint.y);
    CGContextAddLineToPoint(context, lastPoint.x, lastPoint.y);
    CGContextStrokePath(context);
    imgForeground.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

 }
如何取消删除同一图像？

在每次绘图操作后保存一个临时图像。
您应该保存在临时文件上，并限制撤消操作的数量

我的应用程序中也有同样的问题。经过长时间的搜索，我找到了解决这个问题的简单方法

我刚刚使用了
UIViewController

以下是我的方法

代码：-

   #pragma mark touches stuff...



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

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

        CGFloat brushSize;
        if (isEraser) 
        {
            brushSize=eraser;
        }
        else
        {
            brushSize=mark;
        }
        CGColorRef strokeColor = [UIColor whiteColor].CGColor;

        UIGraphicsBeginImageContext(self.editedImageView.frame.size);
        CGContextRef context = UIGraphicsGetCurrentContext();
        [self.editedImageView.image drawInRect:CGRectMake(0, 0, self.editedImageView.frame.size.width, self.editedImageView.frame.size.height)];
        CGContextSetLineCap(context, kCGLineCapRound);
        CGContextSetLineWidth(context, brushSize);
        if (isEraser) {

            CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor colorWithPatternImage:self.im].CGColor);
        }  
        else
        {
            CGContextSetStrokeColorWithColor(context, strokeColor);
            CGContextSetBlendMode(context, kCGBlendModeClear); 
        }
        CGContextBeginPath(context);
        CGContextMoveToPoint(context, lastTouch.x, lastTouch.y);
        CGContextAddLineToPoint(context, currentTouch.x, currentTouch.y);
        CGContextStrokePath(context);
        self.editedImageView.image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        lastTouch = [touch locationInView:self.editedImageView];
    }

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

    }

CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor colorWithPatternImage:self.im].CGColor);

 self.im    =   "Your Custom image";
输入：

self.editedImageView.image = "Your Custom image";

self.im    =   "Your Custom image";
您的问题的简单解决方案是：-

   #pragma mark touches stuff...



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

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

        CGFloat brushSize;
        if (isEraser) 
        {
            brushSize=eraser;
        }
        else
        {
            brushSize=mark;
        }
        CGColorRef strokeColor = [UIColor whiteColor].CGColor;

        UIGraphicsBeginImageContext(self.editedImageView.frame.size);
        CGContextRef context = UIGraphicsGetCurrentContext();
        [self.editedImageView.image drawInRect:CGRectMake(0, 0, self.editedImageView.frame.size.width, self.editedImageView.frame.size.height)];
        CGContextSetLineCap(context, kCGLineCapRound);
        CGContextSetLineWidth(context, brushSize);
        if (isEraser) {

            CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor colorWithPatternImage:self.im].CGColor);
        }  
        else
        {
            CGContextSetStrokeColorWithColor(context, strokeColor);
            CGContextSetBlendMode(context, kCGBlendModeClear); 
        }
        CGContextBeginPath(context);
        CGContextMoveToPoint(context, lastTouch.x, lastTouch.y);
        CGContextAddLineToPoint(context, currentTouch.x, currentTouch.y);
        CGContextStrokePath(context);
        self.editedImageView.image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        lastTouch = [touch locationInView:self.editedImageView];
    }

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

    }

CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor colorWithPatternImage:self.im].CGColor);

 self.im    =   "Your Custom image";
注意：

self.editedImageView.image = "Your Custom image";

self.im    =   "Your Custom image";
这不会再次将图像拉过

更新：-

   #pragma mark touches stuff...



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

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

        CGFloat brushSize;
        if (isEraser) 
        {
            brushSize=eraser;
        }
        else
        {
            brushSize=mark;
        }
        CGColorRef strokeColor = [UIColor whiteColor].CGColor;

        UIGraphicsBeginImageContext(self.editedImageView.frame.size);
        CGContextRef context = UIGraphicsGetCurrentContext();
        [self.editedImageView.image drawInRect:CGRectMake(0, 0, self.editedImageView.frame.size.width, self.editedImageView.frame.size.height)];
        CGContextSetLineCap(context, kCGLineCapRound);
        CGContextSetLineWidth(context, brushSize);
        if (isEraser) {

            CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor colorWithPatternImage:self.im].CGColor);
        }  
        else
        {
            CGContextSetStrokeColorWithColor(context, strokeColor);
            CGContextSetBlendMode(context, kCGBlendModeClear); 
        }
        CGContextBeginPath(context);
        CGContextMoveToPoint(context, lastTouch.x, lastTouch.y);
        CGContextAddLineToPoint(context, currentTouch.x, currentTouch.y);
        CGContextStrokePath(context);
        self.editedImageView.image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        lastTouch = [touch locationInView:self.editedImageView];
    }

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

    }

CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor colorWithPatternImage:self.im].CGColor);

 self.im    =   "Your Custom image";
这将是这样的

-(void)eraserConfigure
{
    UIImageView *resizeImage=[[[UIImageView alloc]initWithImage:editedImage]autorelease];
    /*UIImage */self.im=[UIImage imageFromView:resizeImage scaledToSize:CGSizeMake(self.editedImageView.frame.size.width, self.editedImageView.frame.size.height)];
}
您使用图像上下文构建图像有什么原因吗？这并不能完全解决你的问题，但我会把我的图片放在滚动视图中。如果图像大小大于可视区域，scrollview会自动为您提供滚动。我猜您不明白我的问题，我正在删除图像而不是滚动图像。意思是当我在图像上移动手指时，它将被移除当你说“取消”时，你的意思是“撤消”吗？如果是这样，您是否需要多个级别的撤消（我想是重做）？No buddy我正在使用一种工具，用户可以根据需要擦除和取消擦除图片。
但我无法使用取消擦除tool@ShashankKulshrestha我更新了答案，请检查并让我知道，如果你面临任何错误或疑问…伙计，我正在寻找一些像当用户移动手指在被擦除的区域。。撤销是一种不同的好技术，但它可能会在内存中产生问题，警告将一个图像添加到另一个图像上。另一方面，是的，由于在磁盘上写入和检索二进制文件，它可能会减慢和延迟进程。@ShashankKulshrestha我希望它能帮助你，但它不是一个uneraseThanks spynet此代码正在工作唯一的问题是。。。。它是从wch为-50px的区域中获取颜色的there@ShashankKulshrestha对不起，我不能让你详细说明，以便我能清楚地理解…当我再次在新图像上绘制图像时，在y轴上以-50px以上绘制检查图像视图类型是否为纵横比匹配或纵横比填充可能是这导致了此问题，或者你只是相应地调整大小