Iphone 如何裁剪具有固定尺寸的UIImage?
我有一个尺寸为(0,0320460)的uiimageIphone 如何裁剪具有固定尺寸的UIImage?,iphone,ios,uiimageview,uiimage,crop,Iphone,Ios,Uiimageview,Uiimage,Crop,我有一个尺寸为(0,0320460)的uiimage 如何将此图像裁剪为尺寸(10,30300300)我的代码中的目标尺寸始终设置为设备的全屏尺寸(因此您必须更改它) @实现UIImage(附加) #布拉格标记- #pragma标记比例和裁剪图像 -(UIImage*)图像按缩放和裁剪大小:(CGSize)目标大小 { UIImage*sourceImage=self; UIImage*newImage=nil; CGSize imageSize=sourceImage.size; CGFloa
如何将此图像裁剪为尺寸(10,30300300)我的代码中的目标尺寸始终设置为设备的全屏尺寸(因此您必须更改它)
@实现UIImage(附加)
#布拉格标记-
#pragma标记比例和裁剪图像
-(UIImage*)图像按缩放和裁剪大小:(CGSize)目标大小
{
UIImage*sourceImage=self;
UIImage*newImage=nil;
CGSize imageSize=sourceImage.size;
CGFloat width=imageSize.width;
CGFloat height=图像大小.height;
CGFloat targetWidth=targetSize.width;
CGFloat targetHeight=targetSize.height;
CGFloat scaleFactor=0.0;
CGFloat scaledWidth=targetWidth;
CGFloat缩放高度=目标高度;
CGPoint thumbnailPoint=CGPointMake(0.0,0.0);
if(CGSizeEqualToSize(imageSize,targetSize)==否)
{
CGFloat宽度系数=目标宽度/宽度;
CGFloat高度系数=目标高度/高度;
如果(宽度因子>高度因子)
{
scaleFactor=widthFactor;//缩放以适应高度
}
其他的
{
scaleFactor=heightFactor;//缩放以适应宽度
}
scaledWidth=宽度*缩放因子;
缩放高度=高度*缩放因子;
//将图像居中
如果(宽度因子>高度因子)
{
thumbnailPoint.y=(targetLight-缩放高度)*0.5;
}
其他的
{
if(宽度系数<高度系数)
{
thumbnailPoint.x=(targetWidth-缩放宽度)*0.5;
}
}
}
UIGraphicsBeginImageContext(targetSize);//这将裁剪
CGRect thumbnailRect=CGRectZero;
thumbnailRect.origin=thumbnailPoint;
thumbnailRect.size.width=缩放宽度;
thumbnailRect.size.height=缩放高度;
[sourceImage drawInRect:thumbnailRect];
newImage=UIGraphicsGetImageFromCurrentImageContext();
if(newImage==nil)
{
NSLog(@“无法缩放图像”);
}
//弹出上下文以返回默认值
UIGraphicsSendImageContext();
返回新图像;
}
将边界设置为10、30、300、300+clipToBounds。
@implementation UIImage (Extras)
#pragma mark -
#pragma mark Scale and crop image
- (UIImage*)imageByScalingAndCroppingForSize:(CGSize)targetSize
{
UIImage *sourceImage = self;
UIImage *newImage = nil;
CGSize imageSize = sourceImage.size;
CGFloat width = imageSize.width;
CGFloat height = imageSize.height;
CGFloat targetWidth = targetSize.width;
CGFloat targetHeight = targetSize.height;
CGFloat scaleFactor = 0.0;
CGFloat scaledWidth = targetWidth;
CGFloat scaledHeight = targetHeight;
CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
if (CGSizeEqualToSize(imageSize, targetSize) == NO)
{
CGFloat widthFactor = targetWidth / width;
CGFloat heightFactor = targetHeight / height;
if (widthFactor > heightFactor)
{
scaleFactor = widthFactor; // scale to fit height
}
else
{
scaleFactor = heightFactor; // scale to fit width
}
scaledWidth = width * scaleFactor;
scaledHeight = height * scaleFactor;
// center the image
if (widthFactor > heightFactor)
{
thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
}
else
{
if (widthFactor < heightFactor)
{
thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
}
}
}
UIGraphicsBeginImageContext(targetSize); // this will crop
CGRect thumbnailRect = CGRectZero;
thumbnailRect.origin = thumbnailPoint;
thumbnailRect.size.width = scaledWidth;
thumbnailRect.size.height = scaledHeight;
[sourceImage drawInRect:thumbnailRect];
newImage = UIGraphicsGetImageFromCurrentImageContext();
if(newImage == nil)
{
NSLog(@"could not scale image");
}
//pop the context to get back to the default
UIGraphicsEndImageContext();
return newImage;
}