如何在iOS上以编程方式进行屏幕截图

我找不到Swift 3实现的答案，所以我来尝试一下。

static func screenshotOf(window: UIWindow) -> UIImage? {

    UIGraphicsBeginImageContextWithOptions(window.bounds.size, true, UIScreen.main.scale)

    guard let currentContext = UIGraphicsGetCurrentContext() else {
        return nil
    }

    window.layer.render(in: currentContext)
    guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
        UIGraphicsEndImageContext()
        return nil
    }

    UIGraphicsEndImageContext()
    return image
}

这将适用于 Swift 4.2，截图将保存在库中，但请不要忘记编辑 info.plist @ NSPhotoLibraryAddUsageDescription ：

  @IBAction func takeScreenshot(_ sender: UIButton) {

    //Start full Screenshot
    print("full Screenshot")
    UIGraphicsBeginImageContext(card.frame.size)
    view.layer.render(in: UIGraphicsGetCurrentContext()!)
    var sourceImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    UIImageWriteToSavedPhotosAlbum(sourceImage!, nil, nil, nil)

    //Start partial Screenshot
    print("partial Screenshot")
    UIGraphicsBeginImageContext(card.frame.size)
    sourceImage?.draw(at: CGPoint(x:-25,y:-100)) //the screenshot starts at -25, -100
    var croppedImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    UIImageWriteToSavedPhotosAlbum(croppedImage!, nil, nil, nil)

}

iOS 7.0及以上版本..

如果你想要对视图 (myView) 进行截屏，只需要一行代码：

[myView snapshotViewAfterScreenUpdates:NO];

以下网站提供两种选项：

选项1：使用UIWindow（尝试过并且完美运行）

// create graphics context with screen size
CGRect screenRect = [[UIScreen mainScreen] bounds];
UIGraphicsBeginImageContext(screenRect.size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
[[UIColor blackColor] set];
CGContextFillRect(ctx, screenRect);

// grab reference to our window
UIWindow *window = [UIApplication sharedApplication].keyWindow;

// transfer content into our context
[window.layer renderInContext:ctx];
UIImage *screengrab = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

选项2：使用UIView

// grab reference to the view you'd like to capture
UIView *wholeScreen = self.splitViewController.view;

// define the size and grab a UIImage from it
UIGraphicsBeginImageContextWithOptions(wholeScreen.bounds.size, wholeScreen.opaque, 0.0);
[wholeScreen.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screengrab = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

对于视网膜屏幕（如DenNukem的回答）

// grab reference to our window
    UIWindow *window = [UIApplication sharedApplication].keyWindow;

    // create graphics context with screen size
    CGRect screenRect = [[UIScreen mainScreen] bounds];
    if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
        UIGraphicsBeginImageContextWithOptions(screenRect.size, NO, [UIScreen mainScreen].scale);
    } else {
        UIGraphicsBeginImageContext(screenRect.size);
        [window.layer renderInContext:UIGraphicsGetCurrentContext()];
    }

更多细节请参考：http://pinkstone.co.uk/how-to-take-a-screeshot-in-ios-programmatically/

这篇文章介绍了如何在iOS程序中以编程的方式进行屏幕截图。

从视图中获取屏幕截图

-(UIImage *)getScreenshotImage {
    if ([[UIScreen mainScreen] scale] == 2.0) {
        UIGraphicsBeginImageContextWithOptions(self.view.frame.size, FALSE, 2.0);
    } else {
        UIGraphicsBeginImageContextWithOptions(self.view.frame.size, FALSE, 1.0);
    }

    [self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()];

    UIImage * result = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return result;
}

将图片保存到相册
（注：保留HTML标签）

UIImageWriteToSavedPhotosAlbum(YOUR_IMAGE, nil, nil, nil);

如何做到

UIImageWriteToSavedPhotosAlbum([self getScreenshotImage], nil, nil, nil);

从视图中获取屏幕截图：

- (UIImage *)takeSnapshotView {
    CGRect rect = [myView bounds];//Here you can change your view with myView
    UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
    CGContextRef context = UIGraphicsGetCurrentContext();
    [myView.layer renderInContext:context];
    UIImage *capturedScreen = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return capturedScreen;//capturedScreen is the image of your view
}

希望这是您正在寻找的。如有任何疑问，请回复我。:)

我做了一个按钮，但按下按钮会导致按钮被捕获，所以首先我要取消高亮显示。

- (IBAction)screenShot:(id)sender {
    // Unpress screen shot button
    screenShotButton.highlighted = NO;

    // create graphics context with screen size
    CGRect screenRect = [[UIScreen mainScreen] bounds];

    if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
        UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);
    } else {
        UIGraphicsBeginImageContext(self.view.bounds.size);
    }

    CGContextRef ctx = UIGraphicsGetCurrentContext();
    [[UIColor blackColor] set];
    CGContextFillRect(ctx, screenRect);

    // grab reference to our window
    UIWindow *window = [UIApplication sharedApplication].keyWindow;

    // transfer content into our context
    [window.layer renderInContext:ctx];
    UIImage *screengrab = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    // save screengrab to Camera Roll
    UIImageWriteToSavedPhotosAlbum(screengrab, nil, nil, nil);
}

我从http://pinkstone.co.uk/how-to-take-a-screeshot-in-ios-programmatically/中获取了代码的主体部分, 我使用了选项1, 选项2对我来说似乎无法正常工作。从这个线程中添加了适应Retina屏幕大小的调整和取消屏幕截图按钮的高亮显示。我在Storyboard中使用它, 这是一个由按钮和标签组成的屏幕，并在稍后通过程序添加了几个UIView。

另一种选择是在仪器上使用自动化工具。您可以编写脚本将屏幕设置为您想要的任何状态，然后进行截图。以下是我用于其中一个应用程序的脚本。显然，脚本的细节对于您的应用程序将有所不同。

var target = UIATarget.localTarget();
var app = target.frontMostApp();
var window = app.mainWindow();
var picker = window.pickers()[0];
var wheel = picker.wheels()[2];
var buttons = window.buttons();
var button1 = buttons.firstWithPredicate("name == 'dateButton1'");
var button2 = buttons.firstWithPredicate("name == 'dateButton2'");

function setYear(picker, year) {
    var yearName = year.toString();
    var yearWheel = picker.wheels()[2];
    yearWheel.selectValue(yearName);
}

function setMonth(picker, monthName) {
    var wheel = picker.wheels()[0];
    wheel.selectValue(monthName);
}

function setDay(picker, day) {
    var wheel = picker.wheels()[1];
    var name = day.toString();
    wheel.selectValue(name);
}

target.delay(1);
setYear(picker, 2015);
setMonth(picker, "July");
setDay(picker, 4);
button1.tap();
setYear(picker, 2015);
setMonth(picker, "December");
setDay(picker, 25);

target.captureScreenWithName("daysShot1");

var nButtons = buttons.length;
UIALogger.logMessage(nButtons + " buttons");
for (var i=0; i<nButtons; i++) {
    UIALogger.logMessage("button " + buttons[i].name());
}

var tabBar = window.tabBars()[0];
var barButtons = tabBar.buttons();

var nBarButtons = barButtons.length;
UIALogger.logMessage(nBarButtons + " buttons on tab bar");

for (var i=0; i<nBarButtons; i++) {
    UIALogger.logMessage("button " + barButtons[i].name());
}

var weeksButton = barButtons[1];
var monthsButton = barButtons[2];
var yearsButton = barButtons[3];

target.delay(2);
weeksButton.tap();
target.captureScreenWithName("daysShot2");
target.delay(2);
monthsButton.tap();
target.captureScreenWithName("daysShot3");
target.delay(2);
yearsButton.tap();
target.delay(2);
button2.tap();
target.delay(2);
setYear(picker, 2018);
target.delay(2);
target.captureScreenWithName("daysShot4");

在Swift中，您可以使用以下代码。

if UIScreen.mainScreen().respondsToSelector(Selector("scale")) {
    UIGraphicsBeginImageContextWithOptions(self.window!.bounds.size, false, UIScreen.mainScreen().scale)
}
else{
    UIGraphicsBeginImageContext(self.window!.bounds.size)
}
self.window?.layer.renderInContext(UIGraphicsGetCurrentContext())
var image : UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)

Swift 4：

func makeImage(withView view: UIView) -> UIImage? {

    let rect = view.bounds

    UIGraphicsBeginImageContextWithOptions(rect.size, true, 0)

    guard let context = UIGraphicsGetCurrentContext() else {
      assertionFailure()
      return nil
    }

    view.layer.render(in: context)

    guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
      assertionFailure()
      return nil
    }

    UIGraphicsEndImageContext()

    return image
}