Question

首先，我的应用程序要求用户从collectionview中选择一张照片或者拍摄相机照片，然后导航到裁剪图像编辑器，这样我们的最终图像将根据裁剪区域的位置变成正方形。但是，问题出在那里关于它的几个来源细节。没有UIImagePicker，怎么做？

我也试过拍广场照，没有成功。

我实现了UIPinchGesture imageview，以便用户可以放大或缩小，但图像视图上没有裁剪方块。我必须添加裁剪区域。

这是裁剪UIImage功能：

    func croppImageByRect() -> UIImage {
    let ratio: CGFloat = 1 // square
    let delta: CGFloat
    let offSet: CGPoint

    //make a new square size, that is the resized imaged width
    let newSize = CGSizeMake(size.width, (size.width - size.width / 8))

    //figure out if the picture is landscape or portrait, then
    //calculate scale factor and offset
    if (size.width > size.height) {
        delta = (ratio * size.width - ratio * size.height)
        offSet = CGPointMake(delta / 2, 0)
    } else {
        delta = (ratio * size.height - ratio * size.width)
        offSet = CGPointMake(0, delta / 2)
    }

    //make the final clipping rect based on the calculated values
    let clipRect = CGRectMake(-offSet.x, -offSet.y, (ratio * size.width) + delta, (ratio * size.height) + delta)

    //start a new context, with scale factor 0.0 so retina displays get
    //high quality image
    UIGraphicsBeginImageContextWithOptions(newSize, true, 0.0)

    UIRectClip(clipRect)
    drawInRect(clipRect)
    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return newImage
}

Answer 1

嗯，首先，这一行：

// make a new square size, that is the resized imaged width
let newSize = CGSizeMake(size.width, (size.width - size.width / 8))

由于宽度和高度不同，不会产生方形尺寸。

UIImageView裁剪方块

1 个答案: