Question

如何测量forEach循环的进度并将其显示在进度栏中？我将旋转垂直图像以使其变为水平。每次要转换的图像数量都不同。

这是我要转换的图像的正常工作，我只需要一种向用户显示进度的方法：

func rotateandSave(files: [URL]) {
    files.forEach { file in
        let path = file
        let image = NSImage(contentsOf: path)
        let rotatedImage = image?.rotated(by: rotateAngle)
        saveImage(image: rotatedImage!, destination: path)
    }
}

Answer 1

您可以将ProgressView用于简单的进度栏。您可以像其他任何视图一样将其添加到视图控制器中（作为@IBOutlet弱变量）。在viewDidLoad（）中将进度设置为0，以使栏开始为空。

ProgressView的进度设置在0.0-1.0的范围内，可以设置动画选项（我想您希望这样做）。要更新ProgressView，您可以修改现有功能：

@IBOutlet weak var progressView: UIProgressView!
...    
func rotateandSave(files: [URL]) {
    let numFiles = files.count
    let fileNum = 0
    files.forEach { file in
        let path = file
        let image = NSImage(contentsOf: path)
        let rotatedImage = image?.rotated(by: rotateAngle)
        saveImage(image: rotatedImage!, destination: path)
        progressBar.setProgress(Double(fileNum)/Double(numFiles), true)
        fileNum += 1
    }
}

Answer 2

您可以使用ProgressView显示进度栏。您可以将其添加到您的控制器中，如下所示：

@IBOutlet weak var progressView: UIProgressView!
override func viewDidLoad() {
        super.viewDidLoad()
        progressView.progress = 0.0
} 

func rotateandSave(files: [URL]) {

    var numberOfFile = files.count
    var fileCounter = 0
    files.forEach { file in
        let path = file
        let image = NSImage(contentsOf: path)
        let rotatedImage = image?.rotated(by: rotateAngle)
        saveImage(image: rotatedImage!, destination: path)
        fileCounter + =1
        let progress = (Double(fileCounter)/Double(numberOfFile))
        progressView.setProgress(progress, animated: true)
    }
}

当您的progressView的进度此时达到最大时，您可以执行自己的操作

Answer 3

执行此操作：

func rotateandSave(files: [URL]) {
DispatchQueue.global(qos: .utility).async {
    files.forEach { file in
        let path = file
        let image = NSImage(contentsOf: path)
        let rotatedImage = image?.imageRotated(by: 90)
        saveImage(image: rotatedImage!, destination: path)
        DispatchQueue.main.async {
            self.progressBar.increment(by: 1)
        }
    }
}

快速进入forEach循环的进度栏

3 个答案: