Question

在下面的代码中，即使是小图像放大并填充整个视图。你能帮我看看如何显示图像的原始状态。

    override func drawRect(rect: CGRect) {
    if let inputCIImage = inputCIImage {
        clampFilter.setValue(inputCIImage, forKey: kCIInputImageKey)
        blurFilter.setValue(clampFilter.outputImage!, forKey: kCIInputImageKey)

        let rect = CGRect(x: 0, y: 0, width: drawableWidth, height: drawableHeight)
        ciContext.drawImage(blurFilter.outputImage!, inRect: rect, fromRect: inputCIImage.extent)        
    }
}

Answer 1

我用以下方式想出来：

func aspectFit(fromRect: CGRect, toRect: CGRect) -> CGRect {
    let fromAspectRatio = fromRect.size.width / fromRect.size.height;
    let toAspectRatio = toRect.size.width / toRect.size.height;

    var fitRect = toRect

    if (fromAspectRatio > toAspectRatio) {
        fitRect.size.height = toRect.size.width / fromAspectRatio;
        fitRect.origin.y += (toRect.size.height - fitRect.size.height) * 0.5;
    } else {
        fitRect.size.width = toRect.size.height  * fromAspectRatio;
        fitRect.origin.x += (toRect.size.width - fitRect.size.width) * 0.5;
    }

    return CGRectIntegral(fitRect)
}

func aspectFill(fromRect: CGRect, toRect: CGRect) -> CGRect {
    let fromAspectRatio = fromRect.size.width / fromRect.size.height;
    let toAspectRatio = toRect.size.width / toRect.size.height;

    var fitRect = toRect

    if (fromAspectRatio > toAspectRatio) {
        fitRect.size.width = toRect.size.height  * fromAspectRatio;
        fitRect.origin.x += (toRect.size.width - fitRect.size.width) * 0.5;
    } else {
        fitRect.size.height = toRect.size.width / fromAspectRatio;
        fitRect.origin.y += (toRect.size.height - fitRect.size.height) * 0.5;
    }

    return CGRectIntegral(fitRect)
}
func imageBoundsForContentMode(fromRect: CGRect, toRect: CGRect) -> CGRect {
    switch contentMode {
    case .ScaleAspectFill:
        return aspectFill(fromRect, toRect: toRect)
    case .ScaleAspectFit:
        return aspectFit(fromRect, toRect: toRect)
    default:
        return fromRect
    }
}

override func drawRect(rect: CGRect) {
    if let inputCIImage = inputCIImage {
        clampFilter.setValue(inputCIImage, forKey: kCIInputImageKey)
        blurFilter.setValue(clampFilter.outputImage!, forKey: kCIInputImageKey)

        let rect = CGRect(x: 0, y: 0, width: drawableWidth, height: drawableHeight)

        let inputBounds = inputCIImage.extent

        let targetBounds = imageBoundsForContentMode(inputBounds, toRect: rect)

        ciContext.drawImage(blurFilter.outputImage!, inRect: targetBounds, fromRect: inputCIImage.extent)




    }
}

Answer 2

您可以获得图像的大小，就像您的图像是

一样

let image = UIImage(named: "someImage.png")

然后你可以得到它的宽度和大小

print(image.size)

然后将大小传递给自定义视图以制作所需的大小。

显示图像而不缩放以查看

2 个答案: