iOS Autolayout视图高度基于较大的子视图高度

2019年8月6日 147次阅读

所以我在界面构建器中有一个视图,我希望它的高度基于它内部的两个子视图的较大(高度方向).但是,只有在加载视图并通过viewDidLoad填充内容时才会确定.

所以现在我有基于灰色文本(“S”)的视图底部布局.在应用程序的大多数情况下,灰色文本将足够长以包裹多行,然后视图高度很好.但是,在这种情况下,图像的高度大于文本.在接口构建器中是否有任何方法可以将autolayout约束设置为相对于两者中的较大者(实际上,相对于具有最大maxY帧位置的元素,更准确)？

最佳答案 试试这个：

TestView.xib：

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="7706" systemVersion="14D136" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES">
    <dependencies>
        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="7703"/>
    </dependencies>
    <objects>
        <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner"/>
        <placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
        <view contentMode="scaleToFill" id="iN0-l3-epB">
            <rect key="frame" x="0.0" y="0.0" width="320" height="320"/>
            <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
            <subviews>
                <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="Pbb-AR-WNn">
                    <rect key="frame" x="20" y="87" width="280" height="147"/>
                    <subviews>
                        <imageView userInteractionEnabled="NO" contentMode="scaleToFill" horizontalHuggingPriority="1000" verticalHuggingPriority="1000" horizontalCompressionResistancePriority="1000" verticalCompressionResistancePriority="1000" image="dragon" translatesAutoresizingMaskIntoConstraints="NO" id="D5g-gu-1ev">
                            <rect key="frame" x="16" y="16" width="64" height="64"/>
                        </imageView>
                        <label opaque="NO" userInteractionEnabled="NO" contentMode="left" verticalHuggingPriority="1000" verticalCompressionResistancePriority="1000" lineBreakMode="tailTruncation" numberOfLines="0" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="5iM-Zb-gNn">
                            <rect key="frame" x="88" y="16" width="176" height="115"/>
                            <string key="text">So I have a view in interface builder and I want its height to be based on the larger (height-wise) of the two subviews inside of it.</string>
                            <fontDescription key="fontDescription" type="system" pointSize="16"/>
                            <color key="textColor" cocoaTouchSystemColor="darkTextColor"/>
                            <nil key="highlightedColor"/>
                        </label>
                    </subviews>
                    <color key="backgroundColor" white="0.90000000000000002" alpha="1" colorSpace="calibratedWhite"/>
                    <constraints>
                        <constraint firstAttribute="width" constant="280" id="2xn-1g-Vuq"/>
                        <constraint firstAttribute="bottom" secondItem="D5g-gu-1ev" secondAttribute="bottom" priority="750" constant="16" id="6rO-0a-xvp"/>
                        <constraint firstAttribute="bottom" secondItem="5iM-Zb-gNn" secondAttribute="bottom" priority="750" constant="16" id="B4u-tf-NJf"/>
                        <constraint firstItem="D5g-gu-1ev" firstAttribute="leading" secondItem="Pbb-AR-WNn" secondAttribute="leading" constant="16" id="GZ7-e9-kF0"/>
                        <constraint firstItem="D5g-gu-1ev" firstAttribute="top" secondItem="Pbb-AR-WNn" secondAttribute="top" constant="16" id="K8m-xD-EsT"/>
                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="D5g-gu-1ev" secondAttribute="bottom" constant="16" id="KEK-Q2-z4j"/>
                        <constraint firstItem="5iM-Zb-gNn" firstAttribute="leading" secondItem="D5g-gu-1ev" secondAttribute="trailing" constant="8" id="QLz-Q2-13S"/>
                        <constraint firstItem="5iM-Zb-gNn" firstAttribute="top" secondItem="Pbb-AR-WNn" secondAttribute="top" constant="16" id="bpN-WA-APq"/>
                        <constraint firstAttribute="bottom" relation="greaterThanOrEqual" secondItem="5iM-Zb-gNn" secondAttribute="bottom" constant="16" id="dbe-Qg-fJU"/>
                        <constraint firstAttribute="trailing" secondItem="5iM-Zb-gNn" secondAttribute="trailing" constant="16" id="yIE-Eq-dw0"/>
                    </constraints>
                </view>
            </subviews>
            <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
            <constraints>
                <constraint firstAttribute="centerY" secondItem="Pbb-AR-WNn" secondAttribute="centerY" id="Ts3-XA-WC0"/>
                <constraint firstAttribute="centerX" secondItem="Pbb-AR-WNn" secondAttribute="centerX" id="uS3-QD-gfi"/>
            </constraints>
            <freeformSimulatedSizeMetrics key="simulatedDestinationMetrics"/>
            <point key="canvasLocation" x="365" y="328"/>
        </view>
    </objects>
    <resources>
        <image name="dragon" width="64" height="64"/>
    </resources>
</document>

约束构造如下：

H:[panel(280)]
H:|-16-[imageView]-8-[labelView]-16-|
V:|-16-[imageView]-(16@750,>=16)-|
V:|-16-[labelView]-(16@750,>=16)-|

和

imageView.contentHuggingPriorityForAxis(.Vertical) == 1000
imageView.contentCompressionResistancePriorityForAxis(.Vertical) == 1000

labelView.contentHuggingPriorityForAxis(.Vertical) == 1000
labelView.contentCompressionResistancePriorityForAxis(.Vertical) == 1000
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