How to take a screenshot programmatically on iOS

Question

I want a screenshot of the image on the screen saved into the saved photo library.

Answer 1

Another option is to use the Automation tool on instruments. You write a script to put the screen into whatever you state you want, then take the shots. Here is the script I used for one of my apps. Obviously, the details of the script will be different for your app.

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");

Answer 2

For iOS 7.0 or above..

If you want to take screenshots of view say(myView), you can do this with single line:

[myView snapshotViewAfterScreenUpdates:NO];

Answer 3

See this post it looks like you can use UIGetScreenImage() for now.

Answer 4

This will save a screenshot and as well return the screenshot too.

-(UIImage *)capture{
    UIGraphicsBeginImageContext(self.view.bounds.size);
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *imageView = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    UIImageWriteToSavedPhotosAlbum(imageView, nil, nil, nil); //if you need to save
    return imageView;
}

Answer 5

In Swift you can use following code.

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)

Answer 6

Below method works for OPENGL objects also

//iOS7 or above
- (UIImage *) screenshot {

    CGSize size = CGSizeMake(your_width, your_height);

    UIGraphicsBeginImageContextWithOptions(size, NO, [UIScreen mainScreen].scale);

    CGRect rec = CGRectMake(0, 0, your_width, your_height);
    [_viewController.view drawViewHierarchyInRect:rec afterScreenUpdates:YES];

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}