ios 如何拍摄 UIView 的屏幕截图？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2214957/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How Do I Take a Screen Shot of a UIView?
提问by cduck
I am wondering how my iPhone app can take a screen shot of a specific UIViewas a UIImage.
我想知道我的 iPhone 应用程序如何将特定的屏幕截图UIView作为UIImage.
I tried this code but all I get is a blank image.
我试过这段代码，但我得到的只是一个空白图像。
UIGraphicsBeginImageContext(CGSizeMake(320,480));
CGContextRef context = UIGraphicsGetCurrentContext();
[myUIView.layer drawInContext:context];
UIImage *screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
myUIViewhas dimensions 320x480 an it has some sub-views.
What is the correct way to do this?
myUIView尺寸为 320x480，并且有一些子视图。这样做的正确方法是什么？
采纳答案by Kendall Helmstetter Gelner
I think you may want renderInContext, not drawInContext. drawInContext is more a method you would override...
我想你可能想要renderInContext，不是drawInContext。drawInContext 更像是一个你会覆盖的方法......
Note that it may not work in all views, specifically a year or so ago when I tried to use this with the live camera view it did not work.
请注意，它可能不适用于所有视图，特别是大约一年前，当我尝试将它与实时摄像机视图一起使用时，它不起作用。
回答by Klaas
iOS 7 has a new method that allows you to draw a view hierarchy into the current graphics context. This can be used to get an UIImage very fast.
iOS 7 有一个新方法，允许您将视图层次结构绘制到当前图形上下文中。这可用于非常快速地获取 UIImage。
I implemented a category method on UIViewto get the view as an UIImage:
我实现了一个类别方法UIView来将视图作为一个UIImage：
- (UIImage *)pb_takeSnapshot {
UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, [UIScreen mainScreen].scale);
[self drawViewHierarchyInRect:self.bounds afterScreenUpdates:YES];
// old style [self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
It is considerably faster then the existing renderInContext:method.
它比现有renderInContext:方法快得多。
Reference: https://developer.apple.com/library/content/qa/qa1817/_index.html
参考：https: //developer.apple.com/library/content/qa/qa1817/_index.html
UPDATE FOR SWIFT: An extension that does the same:
更新 SWIFT：一个扩展，做同样的事情：
extension UIView {
func pb_takeSnapshot() -> UIImage {
UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.mainScreen().scale)
drawViewHierarchyInRect(self.bounds, afterScreenUpdates: true)
// old style: layer.renderInContext(UIGraphicsGetCurrentContext())
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
UPDATE FOR SWIFT 3
更新 Swift 3
UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.main.scale)
drawHierarchy(in: self.bounds, afterScreenUpdates: true)
let image = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return image
回答by Tibidabo
You need to capture the key windowfor a screenshot or a UIView. You can do it in Retina Resolutionusing UIGraphicsBeginImageContextWithOptions and set its scale parameter 0.0f. It always captures in native resolution (retina for iPhone 4 and later).
您需要捕获屏幕截图或 UIView的关键窗口。您可以使用 UIGraphicsBeginImageContextWithOptions在Retina Resolution 中执行此操作，并将其缩放参数设置为 0.0f。它始终以原始分辨率捕获（iPhone 4 及更高版本的视网膜）。
This one does a full screen screenshot (key window)
这个做全屏截图（关键窗口）
UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
CGRect rect = [keyWindow bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[keyWindow.layer renderInContext:context];
UIImage *capturedScreen = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
This code capture a UIView in native resolution
此代码以原始分辨率捕获 UIView
CGRect rect = [captureView bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[captureView.layer renderInContext:context];
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
This saves the UIImage in jpg format with 95% quality in the app's document folder if you need to do that.
如果您需要这样做，这会将 UIImage 以 95% 质量的 jpg 格式保存在应用程序的文档文件夹中。
NSString *imagePath = [NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"Documents/capturedImage.jpg"]];
[UIImageJPEGRepresentation(capturedImage, 0.95) writeToFile:imagePath atomically:YES];
回答by san
iOS7 onwards, we have below default methods :
从 iOS7 开始，我们有以下默认方法：
- (UIView *)snapshotViewAfterScreenUpdates:(BOOL)afterUpdates
Calling above method is faster than trying to render the contents of the current view into a bitmap image yourself.
调用上面的方法比自己尝试将当前视图的内容渲染成位图图像要快。
If you want to apply a graphical effect, such as blur, to a snapshot, use the drawViewHierarchyInRect:afterScreenUpdates:method instead.
如果要将图形效果（例如模糊）应用于快照，请改用drawViewHierarchyInRect:afterScreenUpdates:方法。
回答by Mike Demidov
There is new API from iOS 10
iOS 10 有新的 API
extension UIView {
func makeScreenshot() -> UIImage {
let renderer = UIGraphicsImageRenderer(bounds: self.bounds)
return renderer.image { (context) in
self.layer.render(in: context.cgContext)
}
}
}
回答by Hossam Ghareeb
I have created usable extension for UIView to take screenshot in Swift:
我已经为 UIView 创建了可用的扩展来在 Swift 中截取屏幕截图：
extension UIView{
var screenshot: UIImage{
UIGraphicsBeginImageContext(self.bounds.size);
let context = UIGraphicsGetCurrentContext();
self.layer.renderInContext(context)
let screenShot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return screenShot
}
}
To use it just type:
要使用它，只需键入：
let screenshot = view.screenshot
回答by new soul
- (void)drawRect:(CGRect)rect {
UIGraphicsBeginImageContext(self.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
}
This method may put in your Controller class.
此方法可能会放在您的 Controller 类中。
回答by Matt S.
CGImageRef UIGetScreenImage();
Apple now allows us to use it in a public application, even though it's a private API
Apple 现在允许我们在公共应用程序中使用它，即使它是一个私有 API
回答by Vasily Bodnarchuk
Details
细节
- Xcode Version 10.3 (10G8), Swift 5
- Xcode 版本 10.3 (10G8)，Swift 5
Solution
解决方案
import UIKit
extension CALayer {
func makeSnapshot() -> UIImage? {
let scale = UIScreen.main.scale
UIGraphicsBeginImageContextWithOptions(frame.size, false, scale)
defer { UIGraphicsEndImageContext() }
guard let context = UIGraphicsGetCurrentContext() else { return nil }
render(in: context)
let screenshot = UIGraphicsGetImageFromCurrentImageContext()
return screenshot
}
}
extension UIView {
func makeSnapshot() -> UIImage? {
if #available(iOS 10.0, *) {
let renderer = UIGraphicsImageRenderer(size: frame.size)
return renderer.image { _ in drawHierarchy(in: bounds, afterScreenUpdates: true) }
} else {
return layer.makeSnapshot()
}
}
}
Usage
用法
let image = view.makeSnapshot()
Full sample
完整样品
Do not forget to add the solution code here
不要忘记在此处添加解决方案代码
import UIKit
class ViewController: UIViewController {
@IBOutlet var viewForScreenShot: UIView!
@IBOutlet var screenShotRenderer: UIImageView!
@IBAction func makeViewScreenShotButtonTapped2(_ sender: UIButton) {
screenShotRenderer.image = viewForScreenShot.makeSnapshot()
}
}
Main.storyboard
主故事板
<?xml version="1.0" encoding="UTF-8"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="11762" systemVersion="16C67" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="BYZ-38-t0r">
<device id="retina4_7" orientation="portrait">
<adaptation id="fullscreen"/>
</device>
<dependencies>
<deployment identifier="iOS"/>
<plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="11757"/>
<capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
</dependencies>
<scenes>
<!--View Controller-->
<scene sceneID="tne-QT-ifu">
<objects>
<viewController id="BYZ-38-t0r" customClass="ViewController" customModule="stackoverflow_2214957" customModuleProvider="target" sceneMemberID="viewController">
<layoutGuides>
<viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
<viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
</layoutGuides>
<view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
<rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
<autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
<subviews>
<view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="Acg-GO-mMN">
<rect key="frame" x="67" y="28" width="240" height="128"/>
<subviews>
<textField opaque="NO" clipsSubviews="YES" contentMode="scaleToFill" contentHorizontalAlignment="left" contentVerticalAlignment="center" borderStyle="roundedRect" textAlignment="natural" minimumFontSize="17" translatesAutoresizingMaskIntoConstraints="NO" id="4Fr-O3-56t">
<rect key="frame" x="72" y="49" width="96" height="30"/>
<constraints>
<constraint firstAttribute="height" constant="30" id="cLv-es-h7Q"/>
<constraint firstAttribute="width" constant="96" id="ytF-FH-gdm"/>
</constraints>
<nil key="textColor"/>
<fontDescription key="fontDescription" type="system" pointSize="14"/>
<textInputTraits key="textInputTraits"/>
</textField>
</subviews>
<color key="backgroundColor" red="0.0" green="0.47843137250000001" blue="1" alpha="0.49277611300000002" colorSpace="custom" customColorSpace="sRGB"/>
<color key="tintColor" white="0.66666666666666663" alpha="1" colorSpace="calibratedWhite"/>
<constraints>
<constraint firstItem="4Fr-O3-56t" firstAttribute="centerX" secondItem="Acg-GO-mMN" secondAttribute="centerX" id="egj-rT-Gz5"/>
<constraint firstItem="4Fr-O3-56t" firstAttribute="centerY" secondItem="Acg-GO-mMN" secondAttribute="centerY" id="ymi-Ll-WIV"/>
</constraints>
</view>
<button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="SQq-IE-pvj">
<rect key="frame" x="109" y="214" width="157" height="30"/>
<state key="normal" title="make view screen shot"/>
<connections>
<action selector="makeViewScreenShotButtonTapped2:" destination="BYZ-38-t0r" eventType="touchUpInside" id="KSY-ec-uvA"/>
</connections>
</button>
<imageView userInteractionEnabled="NO" contentMode="scaleAspectFit" horizontalHuggingPriority="251" verticalHuggingPriority="251" translatesAutoresizingMaskIntoConstraints="NO" id="CEZ-Ju-Tpq">
<rect key="frame" x="67" y="269" width="240" height="128"/>
<constraints>
<constraint firstAttribute="width" constant="240" id="STo-iJ-rM4"/>
<constraint firstAttribute="height" constant="128" id="tfi-zF-zdn"/>
</constraints>
</imageView>
</subviews>
<color key="backgroundColor" red="0.95941069162436543" green="0.95941069162436543" blue="0.95941069162436543" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
<constraints>
<constraint firstItem="CEZ-Ju-Tpq" firstAttribute="top" secondItem="SQq-IE-pvj" secondAttribute="bottom" constant="25" id="6x1-iB-gKF"/>
<constraint firstItem="Acg-GO-mMN" firstAttribute="leading" secondItem="CEZ-Ju-Tpq" secondAttribute="leading" id="LUp-Be-FiC"/>
<constraint firstItem="SQq-IE-pvj" firstAttribute="top" secondItem="Acg-GO-mMN" secondAttribute="bottom" constant="58" id="Qu0-YT-k9O"/>
<constraint firstItem="Acg-GO-mMN" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="Qze-zd-ajY"/>
<constraint firstItem="Acg-GO-mMN" firstAttribute="trailing" secondItem="CEZ-Ju-Tpq" secondAttribute="trailing" id="b1d-sp-GHD"/>
<constraint firstItem="SQq-IE-pvj" firstAttribute="centerX" secondItem="CEZ-Ju-Tpq" secondAttribute="centerX" id="qCL-AF-Cro"/>
<constraint firstItem="Acg-GO-mMN" firstAttribute="top" secondItem="y3c-jy-aDJ" secondAttribute="bottom" constant="8" symbolic="YES" id="u5Y-eh-oSG"/>
<constraint firstItem="CEZ-Ju-Tpq" firstAttribute="centerY" secondItem="8bC-Xf-vdC" secondAttribute="centerY" id="vkx-JQ-pOF"/>
</constraints>
</view>
<connections>
<outlet property="screenShotRenderer" destination="CEZ-Ju-Tpq" id="8QB-OE-ib6"/>
<outlet property="viewForScreenShot" destination="Acg-GO-mMN" id="jgL-yn-8kk"/>
</connections>
</viewController>
<placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
</objects>
<point key="canvasLocation" x="32.799999999999997" y="37.331334332833585"/>
</scene>
</scenes>
</document>
Result
结果
回答by anthonyqz
I created this extension for save a screen shotfrom UIView
我创建了这个扩展来保存UIView的屏幕截图
extension UIView {
func saveImageFromView(path path:String) {
UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.mainScreen().scale)
drawViewHierarchyInRect(bounds, afterScreenUpdates: true)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageJPEGRepresentation(image, 0.4)?.writeToFile(path, atomically: true)
}}
call:
打电话：
let pathDocuments = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true).first!
let pathImage = "\(pathDocuments)/\(user!.usuarioID.integerValue).jpg"
reportView.saveImageFromView(path: pathImage)
If you want to create a png must change:
如果要创建png必须更改：
UIImageJPEGRepresentation(image, 0.4)?.writeToFile(path, atomically: true)
by
经过
UIImagePNGRepresentation(image)?.writeToFile(path, atomically: true)
