如何拍摄uiview的屏幕截图?

我想你可能想要 renderInContext 不是 drawInContext . DrawInContext更像是一种可以重写的方法…

请注意,它可能在所有视图中都不起作用,特别是在一年左右以前,当我尝试将它与实时摄像头视图一起使用时,它不起作用。

iOS7有一个新方法,允许您将视图层次绘制到当前图形上下文中。这可用于快速获取ui图像。

我在上实现了一个类别方法 UIView 将视图作为 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;
}

它比现有的要快得多 renderInContext: 方法。

参考文献: https://developer.apple.com/library/content/qa/qa1817/_index.html

Swift更新 :执行相同操作的扩展名:

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
    }
}

Swift 3的更新

    UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.main.scale)

    drawHierarchy(in: self.bounds, afterScreenUpdates: true)

    let image = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()
    return image

你需要捕捉 关键窗口 对于屏幕截图或uiview。你可以在里面做 视网膜分辨率 使用uigraphicsBeginImageContextWithOptions并将其比例参数设置为0.0f。它总是以本机分辨率捕获(iPhone4和更高版本的视网膜)。

这个屏幕截图是全屏的(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();

此代码以本机分辨率捕获uiview

CGRect rect = [captureView bounds];
UIGraphicsBeginImageContextWithOptions(rect.size,YES,0.0f);
CGContextRef context = UIGraphicsGetCurrentContext();
[captureView.layer renderInContext:context];   
UIImage *capturedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

如果需要的话,这会将uiimage以JPG格式保存在应用程序的文档文件夹中,质量达到95%。

NSString  *imagePath = [NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"Documents/capturedImage.jpg"]];    
[UIImageJPEGRepresentation(capturedImage, 0.95) writeToFile:imagePath atomically:YES];

IOS7之后,我们有以下默认方法:

- (UIView *)snapshotViewAfterScreenUpdates:(BOOL)afterUpdates

调用上面的方法比自己将当前视图的内容呈现为位图图像要快。

如果要对快照应用图形效果(如模糊),请使用 drawViewHierarchyInRect:afterScreenUpdates: 方法代替。

https://developer.apple.com/library/ios/documentation/uikit/reference/uiview_class/uiview/uiview.html

我已经为uiview创建了可用的扩展,以便在swift中截图:

extension UIView{

var screenshot: UIImage{

    UIGraphicsBeginImageContext(self.bounds.size);
    let context = UIGraphicsGetCurrentContext();
    self.layer.renderInContext(context)
    let screenShot = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return screenShot
}
}

要使用它,只需键入:

let screenshot = view.screenshot

iOS 10提供了新的API

extension UIView {
    func makeScreenshot() -> UIImage {
        let renderer = UIGraphicsImageRenderer(bounds: self.bounds)
        return renderer.image { (context) in
            self.layer.render(in: context.cgContext)
        }
    }
}

- (void)drawRect:(CGRect)rect {
  UIGraphicsBeginImageContext(self.bounds.size);    
  [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
  UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);  
}

此方法可以放入控制器类中。

CGImageRef UIGetScreenImage();

苹果现在允许我们在公共应用程序中使用它,即使它是一个私有的API

苹果不允许:

CGImageRef UIGetScreenImage();

应用程序应使用 drawRect 方法见: http://developer.apple.com/library/ios/#qa/qa2010/qa1703.html

我创造了这个 屏幕截图保存扩展 从UIVIEW

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)

}}

呼叫 :

let pathDocuments = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true).first!
let pathImage = "\(pathDocuments)/\(user!.usuarioID.integerValue).jpg"
reportView.saveImageFromView(path: pathImage)

如果要创建PNG,必须更改:

UIImageJPEGRepresentation(image, 0.4)?.writeToFile(path, atomically: true)

通过

UIImagePNGRepresentation(image)?.writeToFile(path, atomically: true)

以下代码段用于截图:

UIGraphicsBeginImageContext(self.muUIView.bounds.size);

[myUIView.layer renderInContext:UIGraphicsGetCurrentContext()];

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

使用 renderInContext: 方法而不是 drawInContext: 方法

渲染上下文: 方法将接收器及其子层呈现到当前上下文中。这种方法 直接从层树渲染。

详细信息

Xcode 8.2.1,Swift 3

ui快速查看屏幕截图

导入uikit 扩展uiview{ var屏幕截图:uiimage?{ uigraphicsBeginImageContextWithOptions(bounds.size,false,1.0); 如果让u=uigraphicsgetcurrentContext()。{ DrawHierarchy(in:bounds,afterscreenupdates:true) 让屏幕截图=uigraphicsGetImageFromCurrentImageContext() uigraphicsEndImageContext()。 返回屏幕截图 } 返回零 } } < /代码>

使用

screenshotrenderer.image=viewForscreenshot.screenshot
完整的使用示例

< Buff行情>
带uiview扩展名的视图控制器
< /块引用>

导入uikit

类ViewController:uiViewController{

@屏幕显示:uiview!
@iBooklet var屏幕截图趋势器:uiImageView!

重写func viewdidload()。{
super.viewdidload()。
//在加载视图后执行任何其他设置,通常是从NIB加载。
}

@IBaction func makeviewscreenshotbuttonApped2(u sender:uibutton){
screenshotrenderer.image=viewForscreenshot.screenshot
}
}

扩展uiview{

var屏幕截图:uiimage?{
uigraphicsBeginImageContextWithOptions(bounds.size,false,1.0);
如果让u=uigraphicsgetcurrentContext()。{
DrawHierarchy(in:bounds,afterscreenupdates:true)
让屏幕截图=uigraphicsGetImageFromCurrentImageContext()
uigraphicsEndImageContext()。
返回屏幕截图
}
返回零
}
}
< Buff行情>
主要。故事板
< /块引用>

<?xml version=“1.0”encoding=“utf-8”?gt;
<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=“纵向”>
<adaptation id=“fullscreen”/>
&;
<相关性>
<deployment identifier=“iOS”/>
<plugin identifier=“com.apple.interfacebuilder.ibcoatouchplugin”version=“11757”/>
<capability name=“documents saved in the xcode 8 format”mintoolsversion=“8.0”/>gt;
</dependencies>
场景;
&!--视图控制器-->
<scene sceneid=“tne qt ifu”>
对象& gt;
<viewController id=“byz-38-t0r”customClass=“viewController”customModule=“stackOverflow_2214957”customModuleProvider=“target”scenememberid=“viewController”>
<布局指南>
<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”/>gt;
<autoresizingmask key=“autoresizingmask”widthsizable=“yes”heightsizable=“yes”/>gt;
<子视图>
<view contentmode=“scaleToFill”translatesAutoResizingMaskinToConstraints=“no”id=“acg go mmn”>
<rect key=“frame”x=“67”y=“28”width=“240”height=“128”/>gt;
<子视图>
<textfield opaque=“no”clipsSubviews=“yes”contentMode=“scaleToFill”contentHorizontalSignment=“left”contentVerticalAlignment=“center”borderstyle=“roundedRect”textAlignment=“natural”minimumfontsize=“17”translatesAutoResizingMaskingToConstraints=“no”id=“4fr-o3-56t”>
<rect key=“frame”x=“72”y=“49”width=“96”height=“30”/>gt;
<限制>
<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”/>
<textinputraits key=“textinputraits”/>
</textfield>
</Subviews>
<color key=“backgroundcolor”red=“0.0”green=“0.47843137250000001”blue=“1”alpha=“0.492776113000002”colorspace=“custom”custom colorspace=“srgb”/>
<color key=“tingcolor”white=“0.666666666666 3”alpha=“1”colorspace=“calibratedwhite”/>gt;
<限制>
<constraint firstitem=“4fr-o3-56t”firstattribute=“centerx”seconditem=“acg go mmn”secondattribute=“centerx”id=“egj-rt-gz5”/>gt;
<constraint firstitem=“4fr-o3-56t”firstattribute=“centery”seconditem=“acg go mmn”secondattribute=“centery”id=“ymi ll wiv”/>gt;
</constraints>
&Lt/VIEW & GT;
<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”/>gt;
<state key=“Normal”title=“生成视图屏幕截图”/>
<连接>
<action selector=“MakeViewScreensShotButtonApped2:”destination=“byz-38-t0r”eventtype=“TouchupInside”id=“ksy ec uva”/>gt;
</connections>
&按钮/按钮;
<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”/>gt;
<限制>
<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”custom colorspace=“srgb”/>gt;
<限制>
<constraint firstitem=“cez ju tpq”firstattribute=“top”seconditem=“sqq ie pvj”secondattribute=“bottom”constant=“25”id=“6x1 ib gkf”/>gt;
<constraint firstitem=“acg go mmn”firstattribute=“leading”seconditem=“cez ju tpq”secondattribute=“leading”id=“lup be fic”/>gt;
<constraint firstitem=“sqq ie pvj”firstattribute=“top”seconditem=“acg go mmn”secondattribute=“bottom”constant=“58”id=“qu0-yt-k9o”/>gt;
<constraint firstitem=“acg go mmn”firstattribute=“centerx”seconditem=“8bc xf vdc”secondattribute=“centerx”id=“qze zd ajy”/>gt;
<constraint firstitem=“acg go mmn”firstattribute=“trailing”seconditem=“cez ju tpq”secondattribute=“trailing”id=“b1d sp ghd”/>gt;
<constraint firstitem=“sqq ie pvj”firstattribute=“centerx”seconditem=“cez ju tpq”secondattribute=“centerx”id=“qcl af cro”/>gt;
<constraint firstitem=“acg go mmn”firstattribute=“top”seconditem=“y3c jy adj”secondattribute=“bottom”constant=“8”symbol=“yes”id=“u5y eh osg”/>
<constraint firstitem=“cez ju tpq”firstattribute=“centery”seconditem=“8bc xf vdc”secondattribute=“centery”id=“vkx jq pof”/>gt;
</constraints>
&Lt/VIEW & GT;
<连接>
<outlet property=“screenshotrenderer”destination=“cez ju tpq”id=“8qb-oe-ib6”/>
<outlet property=“viewForScreenshot”destination=“acg go mmn”id=“jgl-yn-8kk”/>
</connections>
</viewcontroller>
<placeholderIdentifier=“ibFirstResponder”id=“dkx-z0-nzr”scenememberid=“FirstResponder”/>
</objects>
<point key=“canvasLocation”x=“32.799999999997”y=“37.331334332833585”/>
& /场景& GT;
和/和场景& GT;
</document>
< /代码> 

结果





用法

screenShotRenderer.image = viewForScreenShot.screenShot


_完整的使用示例


带uiview扩展名的视图控制器


import UIKit

class ViewController: UIViewController {

    @IBOutlet var viewForScreenShot: UIView!
    @IBOutlet var screenShotRenderer: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    @IBAction func makeViewScreenShotButtonTapped2(_ sender: UIButton) {
        screenShotRenderer.image = viewForScreenShot.screenShot
    }
}

extension UIView {

    var screenShot: UIImage?  {
        UIGraphicsBeginImageContextWithOptions(bounds.size, false, 1.0);
        if let _ = UIGraphicsGetCurrentContext() {
            drawHierarchy(in: bounds, afterScreenUpdates: true)
            let screenshot = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            return screenshot
        }
        return nil
    }
}



主要故事板


<?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>


结果

-(UIImage *)convertViewToImage
{
    UIGraphicsBeginImageContext(self.bounds.size);
    [self drawViewHierarchyInRect:self.bounds afterScreenUpdates:YES];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

  return image;
}

Swift 4更新:

extension UIView {
   var screenShot: UIImage?  {
        if #available(iOS 10, *) {
            let renderer = UIGraphicsImageRenderer(bounds: self.bounds)
            return renderer.image { (context) in
                self.layer.render(in: context.cgContext)
            }
        } else {
            UIGraphicsBeginImageContextWithOptions(bounds.size, false, 5);
            if let _ = UIGraphicsGetCurrentContext() {
                drawHierarchy(in: bounds, afterScreenUpdates: true)
                let screenshot = UIGraphicsGetImageFromCurrentImageContext()
                UIGraphicsEndImageContext()
                return screenshot
            }
            return nil
        }
    }
}

您可以使用以下uiview类别-

@implementation UIView (SnapShot)

 - (UIImage *)snapshotImage
{
    UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, [UIScreen mainScreen].scale);        
    [self drawViewHierarchyInRect:self.bounds afterScreenUpdates:NO];        
    // old style [self.layer renderInContext:UIGraphicsGetCurrentContext()];        
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();        
    UIGraphicsEndImageContext();        
    return image;
}    
@end