/** TODO:裁剪圖片? @param originalImage 原始圖片 @param size 目標size @return 預(yù)期圖片 */
- (UIImage *)thumbnailWithImage:(UIImage *)originalImage size:(CGSize)size{? ? ? ??
CGSize originalsize = [originalImage size];? ? ? ? //原圖長寬均小于標準長寬的拧篮，不作處理返回原圖? ? ? ?
?if (originalsize.widthsize.width && originalsize.height>size.height)
{
CGFloat rate = 1.0;
CGFloat widthRate = originalsize.width/size.width;
CGFloat heightRate = originalsize.height/size.height;
rate = widthRate>heightRate?heightRate:widthRate;
CGImageRef imageRef = nil;
if (heightRate>widthRate)
{
imageRef = CGImageCreateWithImageInRect([originalImage CGImage], CGRectMake(0, originalsize.height/2-size.height*rate/2, originalsize.width, size.height*rate));//獲取圖片整體部分
}
else
{
imageRef = CGImageCreateWithImageInRect([originalImage CGImage], CGRectMake(originalsize.width/2-size.width*rate/2, 0, size.width*rate, originalsize.height));//獲取圖片整體部分
}
UIGraphicsBeginImageContext(size);//指定要繪畫圖片的大小
CGContextRef con = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(con, 0.0, size.height);
CGContextScaleCTM(con, 1.0, -1.0);
CGContextDrawImage(con, CGRectMake(0, 0, size.width, size.height), imageRef);
UIImage *standardImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGImageRelease(imageRef);
return standardImage;
}
//原圖長寬有一項大于標準長寬的糕殉，對大于標準的那一項進行裁剪锻梳，另一項保持不變
else if(originalsize.height>size.height || originalsize.width>size.width)
{
CGImageRef imageRef = nil;
if(originalsize.height>size.height)
{
imageRef = CGImageCreateWithImageInRect([originalImage CGImage], CGRectMake(0, originalsize.height/2-size.height/2, originalsize.width, size.height));//獲取圖片整體部分
}
else if (originalsize.width>size.width)
{
imageRef = CGImageCreateWithImageInRect([originalImage CGImage], CGRectMake(originalsize.width/2-size.width/2, 0, size.width, originalsize.height));//獲取圖片整體部分
}
UIGraphicsBeginImageContext(size);//指定要繪畫圖片的大小
CGContextRef con = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(con, 0.0, size.height);
CGContextScaleCTM(con, 1.0, -1.0);
CGContextDrawImage(con, CGRectMake(0, 0, size.width, size.height), imageRef);
UIImage *standardImage = UIGraphicsGetImageFromCurrentImageContext();
NSLog(@"改變后圖片的寬度為%f,圖片的高度為%f",[standardImage size].width,[standardImage size].height);
UIGraphicsEndImageContext();
CGImageRelease(imageRef);
return standardImage;
}
//原圖為標準長寬的，不做處理
else
{
return originalImage;
}
}
