最近幾個月一直在忙項目，項目昨天做了上線，今天的時間比較充足，對項目中的圖片處理做個簡單的總結(jié)，希望廣大朋友們支持一下
完整Demo地址
OC版：https://github.com/GaoQianpu/QPImageToor_Obj-C
swif版：https://github.com/GaoQianpu/QPImageToor
1、改變image的size
CGRectrect =CGRectMake(0,0, size.width, size.height);
UIGraphicsBeginImageContextWithOptions(size,NO,2.0);
//關(guān)鍵步驟：在rect內(nèi)將該圖片畫進(jìn)去
[imagedrawInRect:rect];
UIImage* scaledImage =UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
2、image的裁剪（此處我將圖片居中裁剪成為正方形，大家可根據(jù)自己的需求調(diào)整）
此處swift和OC使用不同的API，但是原理還是相同的
注意！！在進(jìn)行截圖的時候自己一定要算對尺寸，因?yàn)楫?dāng)裁剪范圍超出 圖片范圍后，得到的image為空
當(dāng)然這里也可以用貝塞爾曲線，選擇出自己需要的區(qū)域，然后再把這部分圖像給畫上去，這部分代碼在后續(xù)寫貝塞爾曲線的時候再寫，這里就不贅述了
OC:
CGRectrect =CGRectZero;
//計算rect使截圖居中
if(image.size.width>image.size.height) {
rect =CGRectMake((image.size.width-image.size.height)*0.5,0, image.size.height, image.size.height);
}else{
rect =CGRectMake(0, (image.size.height-image.size.width)*0.5, image.size.width, image.size.width);
}
CGImageRefsubImageRef =CGImageCreateWithImageInRect(image.CGImage, rect);
CGRectsmallBounds =CGRectMake(0,0,CGImageGetWidth(subImageRef),CGImageGetHeight(subImageRef));
UIGraphicsBeginImageContextWithOptions(smallBounds.size,NO,2.0);
CGContextRefcontext =UIGraphicsGetCurrentContext();
CGContextDrawImage(context, smallBounds, subImageRef);
UIImage* newImage = [UIImageimageWithCGImage:subImageRef];
UIGraphicsEndImageContext();
swift:
//因?yàn)樵趕wif中，CGImageRef被取消，不過本質(zhì)還是指image的CGImage
varpoint =CGPoint.zero
varsize =CGSize.zero
ifimage.size.width> image.size.height{
point =CGPoint(x: (image.size.width- image.size.height) *0.5, y:0)
size.height= image.size.height
size.width= image.size.height
}else{
point =CGPoint(x:0, y: (image.size.height- image.size.width) *0.5)
size.width= image.size.width
size.height= image.size.width
}
letimageRef = image.cgImage
letsubImageRef = imageRef!.cropping(to:CGRect(origin: point, size: size))
letnewImage =UIImage(cgImage: subImageRef!)
2、image的拉伸
正常情況下修改UIImageView，UIButton等控件的size，會隨意拉伸其中的UIImage，使圖片變形，如果圖形全靠美工妹子切的話，那可憐的猿猿們該單身到多會兒啊，為了廣大單身同志的幸福，大家肯定是愿意多寫幾行代碼，而不是葬送自己撩到妹的機(jī)會，因?yàn)楫吘垢汩_發(fā)的平時很難接觸到太多的妹子，你們說是不？
現(xiàn)在iOS已經(jīng)基本上都在iOS 8以上了，所以iOS 8以前的API基本上用不到了，不過我還是把代碼貼出來讓大家一飽眼福
iOS 6以上
CGFloattop = image.size.height*0.5;
CGFloatleft = image.size.width*0.5;
CGFloatbottom = image.size.height*0.5;
CGFloatright = image.size.width*0.5;
UIEdgeInsetsedgeInsets =UIEdgeInsetsMake(top, left, bottom, right);
UIImageResizingModemode =UIImageResizingModeStretch;
newImage = [imageresizableImageWithCapInsets:edgeInsetsresizingMode:mode];
iOS 5 --- iOS 6
CGFloattop = image.size.height*0.5;
CGFloatleft = image.size.width*0.5;
CGFloatbottom = image.size.height*0.5;
CGFloatright = image.size.width*0.5;
UIEdgeInsetsedgeInsets =UIEdgeInsetsMake(top, left, bottom, right);
UIImageResizingModemode =UIImageResizingModeStretch;
newImage = [imageresizableImageWithCapInsets:edgeInsetsresizingMode:mode];
iOS 5以下
CGFloattop = image.size.height*0.5;
CGFloatleft = image.size.width*0.5;
CGFloatbottom = image.size.height*0.5;
CGFloatright = image.size.width*0.5;
UIEdgeInsetsedgeInsets =UIEdgeInsetsMake(top, left, bottom, right);
newImage = [imageresizableImageWithCapInsets:edgeInsets];
3、image的拼接
//拼接尺寸及坐標(biāo)
UIImage* image1 =[UIImage imageNamed:@"1"];
UIImage* image2 =[UIImage imageNamed:@"2"];
CGRectrect1 =CGRectMake(0,0,image1.size.width,image1.size.height);
CGRectrect2 =CGRectMake(0,image1.size.height+5,image2.size.width, im2.size.height);
//拼接圖片后的總大小
CGSizesize =CGSizeMake(200,image1.size.height+ im2.size.height+5);
UIGraphicsBeginImageContextWithOptions(size,false,2.0);
[image1drawInRect:rect1];//把第一張圖畫上去
[image2drawInRect:rect2];//把第二張畫上去
UIImage* drawImage =UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
最后，再給大家說下我的Demo下載地址
完整Demo地址
