我正在使用iOS的应用程序,使用
Swift和Parse.com
我试图让用户从图像选择器中选择图片,然后将所选图像的大小调整为200×200像素,然后再上传到我的后端.
Parse.com有一个名为“AnyPic”的Instagram复制应用程序的教程,它提供了用于调整图像大小的代码,但它在Objective-C ….
// Resize the image to be square (what is shown in the preview)
UIImage *resizedImage = [anImage resizedImageWithContentMode:UIViewContentModeScaleAspectFit
bounds:CGSizeMake(560.0f,560.0f)
interpolationQuality:kCGInterpolationHigh];
// Create a thumbnail and add a corner radius for use in table views
UIImage *thumbnailImage = [anImage thumbnailImage:86.0f
transparentBorder:0.0f
cornerRadius:10.0f
interpolationQuality:kCGInterpolationDefault];
解决方法
swift中的图像大小调整功能如下.
func resizeImage(image: UIImage,targetSize: CGSize) -> UIImage {
let size = image.size
let widthRatio = targetSize.width / image.size.width
let heightRatio = targetSize.height / image.size.height
// Figure out what our orientation is,and use that to form the rectangle
var newSize: CGSize
if(widthRatio > heightRatio) {
newSize = CGSizeMake(size.width * heightRatio,size.height * heightRatio)
} else {
newSize = CGSizeMake(size.width * widthRatio,size.height * widthRatio)
}
// This is the rect that we've calculated out and this is what is actually used below
let rect = CGRectMake(0,newSize.width,newSize.height)
// Actually do the resizing to the rect using the ImageContext stuff
UIGraphicsBeginImageContextWithOptions(newSize,false,1.0)
image.drawInRect(rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
self.resizeImage(UIImage(named: "yourImageName")!,targetSize: CGSizeMake(200.0,200.0))
查看我的博文,Resize image in swift and objective C,了解更多细节.
swift3已更新
func resizeImage(image: UIImage,and use that to form the rectangle
var newSize: CGSize
if(widthRatio > heightRatio) {
newSize = CGSize(width: size.width * heightRatio,height: size.height * heightRatio)
} else {
newSize = CGSize(width: size.width * widthRatio,height: size.height * widthRatio)
}
// This is the rect that we've calculated out and this is what is actually used below
let rect = CGRect(x: 0,y: 0,width: newSize.width,height: newSize.height)
// Actually do the resizing to the rect using the ImageContext stuff
UIGraphicsBeginImageContextWithOptions(newSize,1.0)
image.draw(in: rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!
}
