Iphone 旋转图像自定义度

我想以自定义角度旋转UIImage（不是UIImageView） 我跟着，但对我不起作用

有人能帮忙吗？谢谢

更新： 下面的代码完成了部分工作，但旋转后我丢失了部分图像：

我应该做什么改变才能把它做好？（顺便说一句，屏幕截图中的黄色是我的UIImageView背景）

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你必须这样做

YourContainer.transform = CGAffineTransformMakeRotation( 270.0/180*M_PI );

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我想剩下的事情你可以想出来。

这个方法会返回你旋转角度的图像

#pragma mark -
#pragma mark Rotate Image 

- (UIImage *)scaleAndRotateImage:(UIImage *)image  { 

    CGImageRef imgRef = image.CGImage;

    CGFloat width = CGImageGetWidth(imgRef);
    CGFloat height = CGImageGetHeight(imgRef);

    CGAffineTransform transform = CGAffineTransformIdentity;
    CGRect bounds = CGRectMake(0, 0, width, height);

    CGFloat boundHeight;

    boundHeight = bounds.size.height;  
    bounds.size.height = bounds.size.width; 
    bounds.size.width = boundHeight;
    transform = CGAffineTransformMakeScale(-1.0, 1.0);
    transform = CGAffineTransformRotate(transform, M_PI / 2.0); //use angle/360 *MPI

    UIGraphicsBeginImageContext(bounds.size);   
    CGContextRef context = UIGraphicsGetCurrentContext();   
    CGContextConcatCTM(context, transform); 
    CGContextDrawImage(context, CGRectMake(0, 0, width, height), imgRef);
    UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return imageCopy;   

}

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此函数可旋转其中心的任何图像，但图像会变成正方形，因此我建议在此函数之后绘制图像时参考图像中心。

要实现此功能，您需要解决两个问题

您正在围绕图像的下角而不是中心旋转

现在旋转图像以使其适合，结果图像的边框需要更大

若要解决围绕中心的旋转问题，请首先执行到中心的平移，然后旋转，然后向后平移

CGAffineTransform transform = CGAffineTransformIdentity;
transform = CGAffineTransformTranslate(transform, boundingRect.size.width/2, boundingRect.size.height/2);
transform = CGAffineTransformRotate(transform, angle);
transform = CGAffineTransformScale(transform, 1.0, -1.0);

CGContextConcatCTM(context, transform);

// Draw the image into the context
CGContextDrawImage(context, CGRectMake(-imageView.image.size.width/2, -imageView.image.size.height/2, imageView.image.size.width, imageView.image.size.height), imageView.image.CGImage);

// Get an image from the context
rotatedImage = [UIImage imageWithCGImage: CGBitmapContextCreateImage(context)];

要计算边界矩形的大小，您需要将新的旋转图像适配到以下位置：

- (CGRect) getBoundingRectAfterRotation: (CGRect) rectangle byAngle: (CGFloat) angleOfRotation {
    // Calculate the width and height of the bounding rectangle using basic trig
    CGFloat newWidth = rectangle.size.width * fabs(cosf(angleOfRotation)) + rectangle.size.height * fabs(sinf(angleOfRotation));
    CGFloat newHeight = rectangle.size.height * fabs(cosf(angleOfRotation)) + rectangle.size.width * fabs(sinf(angleOfRotation));

    // Calculate the position of the origin
    CGFloat newX = rectangle.origin.x + ((rectangle.size.width - newWidth) / 2);
    CGFloat newY = rectangle.origin.y + ((rectangle.size.height - newHeight) / 2);

    // Return the rectangle
    return CGRectMake(newX, newY, newWidth, newHeight);
}

您可以在我以前的帖子和答案中找到这些技巧：

在这里：

希望这有帮助

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用于旋转图像的Dave

。。您可以使用此iAction。。。每次点击按钮，图像都会旋转90度

-(IBAction)rotateImageClick:(id)sender{

UIImage *image2=[[UIImage alloc]init];
image2 = [self imageRotatedByDegrees:self.roateImageView.image deg:(90)]; //Angle by 90 degree
self.roateImageView.image = image2;
imgData= UIImageJPEGRepresentation(image2,0.9f);

}

对于旋转图像，u只需通过以下方法的UIimage和旋转度

- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees

//------------------------------------------------------------------------

#pragma mark - imageRotatedByDegrees Method

- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees{

    // calculate the size of the rotated view's containing box for our drawing space
    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,oldImage.size.width, oldImage.size.height)];

    CGAffineTransform t = CGAffineTransformMakeRotation(degrees * M_PI / 180);
    rotatedViewBox.transform = t;

    CGSize rotatedSize = rotatedViewBox.frame.size;
    // Create the bitmap context
    UIGraphicsBeginImageContext(rotatedSize);
    CGContextRef bitmap = UIGraphicsGetCurrentContext();

    // Move the origin to the middle of the image so we will rotate and scale around the center.
    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);

    //   // Rotate the image context
    CGContextRotateCTM(bitmap, (degrees * M_PI / 180));

    // Now, draw the rotated/scaled image into the context
    CGContextScaleCTM(bitmap, 1.0, -1.0);
    CGContextDrawImage(bitmap, CGRectMake(-oldImage.size.width / 2, -oldImage.size.height / 2, oldImage.size.width, oldImage.size.height), [oldImage CGImage]);

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;

}

我想这个链接会有帮助的。。。。。。。！通过单击目标C中的按钮旋转原始图像

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除了他想旋转图像本身，而不是包含图像的视图。这个代码将图像旋转90度，对吗？如果我只需要向左或向右旋转5度怎么办？太好了！imageCopy是否处于自动释放模式？图像旋转但倒置。图像旋转但翻转到Hi，此代码不适用于与UIImageOrientationUp方向不同的照片，您有任何解决方案吗？Hi如果我旋转30左右的角度，它将从左修剪图像。

- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees

#pragma mark - imageRotatedByDegrees Method

- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees{

    // calculate the size of the rotated view's containing box for our drawing space
    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,oldImage.size.width, oldImage.size.height)];

    CGAffineTransform t = CGAffineTransformMakeRotation(degrees * M_PI / 180);
    rotatedViewBox.transform = t;

    CGSize rotatedSize = rotatedViewBox.frame.size;
    // Create the bitmap context
    UIGraphicsBeginImageContext(rotatedSize);
    CGContextRef bitmap = UIGraphicsGetCurrentContext();

    // Move the origin to the middle of the image so we will rotate and scale around the center.
    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);

    //   // Rotate the image context
    CGContextRotateCTM(bitmap, (degrees * M_PI / 180));

    // Now, draw the rotated/scaled image into the context
    CGContextScaleCTM(bitmap, 1.0, -1.0);
    CGContextDrawImage(bitmap, CGRectMake(-oldImage.size.width / 2, -oldImage.size.height / 2, oldImage.size.width, oldImage.size.height), [oldImage CGImage]);

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;

}