如何在Swift中调整图片大小？

  • Z时代
  • 2024-01-10
  • 分类：问答

我正在使用 和Parse.com开发适用于iOS的应用程序

我试图让用户从图像选择器中选择一张图片，然后将所选图像的大小调整为200x200像素，然后再上传到我的后端。

Parse.com有一个用于Instagram复制应用程序的教程，名为“ AnyPic”，其中提供了用于调整图像大小的代码，但这是在Objective-

C中。

// 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];

回答：

有关更多详细信息，请参阅我的博客文章， 。

快速调整图像尺寸的功能如下。

func resizeImage(image: UIImage, targetSize: CGSize) -> UIImage {
    let size = image.size
    let widthRatio  = targetSize.width  / size.width
    let heightRatio = targetSize.height / 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, 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
}

使用上面的功能并使用200 * 200调整图像大小，如下代码

self.resizeImage(UIImage(named: "yourImageName")!, targetSize: CGSizeMake(200.0, 200.0))

 func resizeImage(image: UIImage, targetSize: CGSize) -> UIImage {
    let size = image.size
    let widthRatio  = targetSize.width  / size.width
    let heightRatio = targetSize.height / size.height
    // Figure out what our orientation is, 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, false, 1.0)
    image.draw(in: rect)
    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return newImage!
}

以上是 如何在Swift中调整图片大小？ 的全部内容， 来源链接： utcz.com/qa/415980.html

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