Objective-C iOS裁剪图像使用缩放？ [英] Objective-C iOS Crop Image Using Zoom?

问题描述

我正在尝试使用此代码来允许用户在我的应用中缩放和裁剪图像：
https://github.com/iosdeveloper/ImageCropper/tree/master/Classes/ImageCropper

I am trying to use this code to allow users to zoom and crop their images in my app: https://github.com/iosdeveloper/ImageCropper/tree/master/Classes/ImageCropper

code snippet

code snippet

float zoomScale = 1.0 / [scrollView zoomScale];

CGRect rect;
rect.origin.x = [scrollView contentOffset].x * zoomScale;
rect.origin.y = [scrollView contentOffset].y * zoomScale;
rect.size.width = [scrollView bounds].size.width * zoomScale;
rect.size.height = [scrollView bounds].size.height * zoomScale;

CGImageRef cr = CGImageCreateWithImageInRect([[imageView image] CGImage], rect);

UIImage *cropped = [UIImage imageWithCGImage:cr];

CGImageRelease(cr);

[delegate imageCropper:self didFinishCroppingWithImage:cropped];

但它没有考虑旋转的图像（我猜这是iPhone上的某种元数据）图片）。我不想让用户绘制一个矩形来裁剪，因为我更喜欢这个界面。

But it does not take into account images being rotated (I guess it's some sort of metadata on the iPhone images). I do not want to have users draw a rectangle to crop as I much prefer this interface.

有人能告诉我如何让它不旋转我的图像吗？

Can someone tell me how to make it not rotate my images?

我在iOS 5& 6如果有帮助的话。

I am building in iOS 5 & 6 if that helps.

此外，这在Game Center应用程序中很好地完成了上传你的个人资料图片。有人知道我在哪里可以找到代码吗？

Also, this is done nicely in the Game Center application for uploading your profile picture. Anyone know where I can find the code for that?

推荐答案

我在这里找到了一个帮助我做我想要的答案
iOS：裁剪从具有叠加层的UIImagePickerController摄像头抓取的静止图像

I found an answer here that helped me do what I wanted iOS: Cropping a still image grabbed from a UIImagePickerController camera with overlay

感兴趣的代码片段

float zoomScale = 1.0 / [scrollView zoomScale];

CGRect rect;
NSLog(@"contentOffset is :%f,%f",[scrollView contentOffset].x,[scrollView contentOffset].y);
rect.origin.x = fabsf([scrollView contentOffset].x * zoomScale);
rect.origin.y = fabsf([scrollView contentOffset].y * zoomScale);
rect.size.width = fabsf([scrollView bounds].size.width * zoomScale);
rect.size.height = fabsf([scrollView bounds].size.height * zoomScale);

UIGraphicsBeginImageContextWithOptions( CGSizeMake( rect.size.width,
                                                   rect.size.height),
                                       NO,
                                       0.);
[[imageView image] drawAtPoint:CGPointMake( -rect.origin.x, -rect.origin.y)
            blendMode:kCGBlendModeCopy
                alpha:1.];
UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

这篇关于Objective-C iOS裁剪图像使用缩放？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！