我正在尝试为 GitHub ( https://github.com/googlecodelabs/constraint-layout) 上托管的培训运行示例程序。
我更新了 build.gradle 以修复构建错误，但我无法编译和运行它。我得到了
No resource identifier found for attribute 'barrierDirection' in package 'com.google.googleio'
No resource identifier found for attribute 'constraint_referenced_ids' in package 'com.google.googleio'
我正在使用 Android Studio 2.3.3。
build.gradle(模块:应用程序)
apply plugin: 'com.android.application'
android {
compileSdkVersion 25
buildToolsVersion "25.0.3"
defaultConfig {
applicationId "com.google.googleio"
minSdkVersion 22
targetSdkVersion 25
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
}
activity_main_done.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main_done"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_editor_absoluteX="0dp"
app:layout_editor_absoluteY="80dp"
tools:layout_editor_absoluteX="0dp"
tools:layout_editor_absoluteY="80dp">
<ImageView
android:src="@drawable/singapore"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_editor_absoluteX="0dp"
app:layout_editor_absoluteY="0dp"
android:id="@+id/header"
android:scaleType="centerCrop"
android:contentDescription="@string/placeholder"
app:layout_constraintLeft_creator="1"
app:layout_constraintTop_creator="1"
app:layout_constraintRight_creator="1"
app:layout_constraintBottom_creator="1"
tools:layout_editor_absoluteX="0dp"
tools:layout_editor_absoluteY="0dp"
app:layout_constraintLeft_toLeftOf="@+id/activity_main_done"
tools:layout_constraintLeft_creator="1"
app:layout_constraintTop_toTopOf="@+id/activity_main_done"
tools:layout_constraintTop_creator="1"
app:layout_constraintRight_toRightOf="@+id/activity_main_done"
tools:layout_constraintRight_creator="1"
app:layout_constraintBottom_toBottomOf="@+id/favorite"
android:layout_marginBottom="16dp"
tools:layout_constraintBottom_creator="1"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintVertical_bias="0.0" />
<ImageView
android:src="@drawable/ic_star"
android:layout_width="36dp"
android:layout_height="36dp"
app:layout_editor_absoluteX="359dp"
app:layout_editor_absoluteY="104dp"
android:id="@+id/favorite"
android:background="@drawable/info_background"
android:padding="5dp"
android:contentDescription="@string/placeholder"
app:layout_constraintTop_creator="1"
app:layout_constraintRight_creator="1"
app:layout_constraintBottom_creator="0"
tools:layout_editor_absoluteX="359dp"
tools:layout_editor_absoluteY="104dp"
app:layout_constraintTop_toTopOf="@+id/activity_main_done"
tools:layout_constraintTop_creator="0"
app:layout_constraintRight_toRightOf="@+id/activity_main_done"
android:layout_marginEnd="16dp"
tools:layout_constraintRight_creator="0"
app:layout_constraintBottom_toBottomOf="@+id/activity_main_done"
android:layout_marginBottom="16dp"
tools:layout_constraintBottom_creator="0"
app:layout_constraintVertical_bias="0.19" />
<TextView
android:text="@string/singapore"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_editor_absoluteX="16dp"
app:layout_editor_absoluteY="140dp"
android:id="@+id/title"
android:textSize="24sp"
app:layout_constraintLeft_creator="1"
app:layout_constraintTop_creator="0"
tools:layout_editor_absoluteX="16dp"
tools:layout_editor_absoluteY="140dp"
app:layout_constraintLeft_toLeftOf="@+id/activity_main_done"
android:layout_marginStart="16dp"
tools:layout_constraintLeft_creator="0"
app:layout_constraintTop_toBottomOf="@+id/header"
android:layout_marginTop="16dp"
tools:layout_constraintTop_creator="0" />
<EditText
android:layout_width="0dp"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:text="@string/camera_value"
android:ems="10"
app:layout_editor_absoluteX="73dp"
app:layout_editor_absoluteY="176dp"
android:id="@+id/cameraType"
app:layout_constraintLeft_creator="1"
app:layout_constraintTop_creator="1"
app:layout_constraintRight_creator="1"
app:layout_constraintLeft_toLeftOf="@+id/settings"
tools:layout_constraintLeft_creator="1"
app:layout_constraintTop_toBottomOf="@+id/title"
android:layout_marginTop="8dp"
tools:layout_constraintTop_creator="0"
app:layout_constraintRight_toRightOf="@+id/settings"
tools:layout_constraintRight_creator="1"
app:layout_constraintStart_toEndOf="@+id/labelBarrier"
android:layout_marginStart="8dp" />
<TextView
android:text="@string/camera"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_editor_absoluteX="16dp"
app:layout_editor_absoluteY="189dp"
android:id="@+id/cameraLabel"
android:labelFor="@+id/cameraType"
app:layout_constraintLeft_creator="1"
app:layout_constraintBaseline_creator="1"
tools:layout_editor_absoluteX="16dp"
tools:layout_editor_absoluteY="189dp"
app:layout_constraintLeft_toLeftOf="@+id/activity_main_done"
android:layout_marginStart="16dp"
tools:layout_constraintLeft_creator="0"
app:layout_constraintBaseline_toBaselineOf="@+id/cameraType"
tools:layout_constraintBaseline_creator="0" />
<TextView
android:text="@string/settings"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_editor_absoluteX="16dp"
app:layout_editor_absoluteY="238dp"
android:id="@+id/settingsLabel"
android:labelFor="@+id/settings"
app:layout_constraintLeft_creator="1"
app:layout_constraintBaseline_creator="1"
tools:layout_editor_absoluteX="16dp"
tools:layout_editor_absoluteY="238dp"
app:layout_constraintLeft_toLeftOf="@+id/activity_main_done"
android:layout_marginStart="16dp"
tools:layout_constraintLeft_creator="0"
app:layout_constraintBaseline_toBaselineOf="@+id/settings"
tools:layout_constraintBaseline_creator="0" />
<android.support.constraint.Barrier
android:id="@+id/labelBarrier"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:barrierDirection="end"
app:constraint_referenced_ids="cameraLabel,settingsLabel" />
<EditText
android:layout_width="0dp"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:text="@string/camera_settings"
android:ems="10"
app:layout_editor_absoluteX="73dp"
app:layout_editor_absoluteY="225dp"
android:id="@+id/settings"
app:layout_constraintLeft_creator="1"
app:layout_constraintTop_creator="1"
app:layout_constraintRight_creator="1"
tools:layout_constraintLeft_creator="1"
app:layout_constraintTop_toBottomOf="@+id/cameraType"
android:layout_marginTop="8dp"
tools:layout_constraintTop_creator="0"
app:layout_constraintRight_toRightOf="@+id/description"
tools:layout_constraintRight_creator="1"
app:layout_constraintStart_toEndOf="@+id/labelBarrier"
android:layout_marginStart="8dp" />
<Button
android:text="@string/upload"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_editor_absoluteX="307dp"
app:layout_editor_absoluteY="538dp"
android:id="@+id/upload"
app:layout_constraintRight_creator="1"
app:layout_constraintBottom_creator="1"
tools:layout_editor_absoluteX="307dp"
tools:layout_editor_absoluteY="538dp"
app:layout_constraintRight_toRightOf="@+id/activity_main_done"
android:layout_marginEnd="16dp"
tools:layout_constraintRight_creator="0"
app:layout_constraintBottom_toBottomOf="@+id/activity_main_done"
android:layout_marginBottom="16dp"
tools:layout_constraintBottom_creator="0" />
<Button
android:text="@string/discard"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_editor_absoluteX="211dp"
app:layout_editor_absoluteY="538dp"
android:id="@+id/discard"
android:elevation="0dp"
app:layout_constraintRight_creator="0"
app:layout_constraintBaseline_creator="1"
tools:layout_editor_absoluteX="211dp"
tools:layout_editor_absoluteY="538dp"
app:layout_constraintRight_toLeftOf="@+id/upload"
android:layout_marginEnd="8dp"
tools:layout_constraintRight_creator="0"
app:layout_constraintBaseline_toBaselineOf="@+id/upload"
tools:layout_constraintBaseline_creator="0" />
<TextView
android:text="@string/singapore_description"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_editor_absoluteX="16dp"
app:layout_editor_absoluteY="274dp"
android:id="@+id/description"
android:fadingEdge="vertical"
android:ellipsize="end"
android:textSize="15sp"
app:layout_constraintLeft_creator="1"
app:layout_constraintTop_creator="0"
app:layout_constraintRight_creator="1"
app:layout_constraintBottom_creator="0"
tools:layout_editor_absoluteX="16dp"
tools:layout_editor_absoluteY="274dp"
app:layout_constraintLeft_toLeftOf="@+id/activity_main_done"
android:layout_marginStart="16dp"
tools:layout_constraintLeft_creator="1"
app:layout_constraintTop_toBottomOf="@+id/settings"
android:layout_marginTop="8dp"
tools:layout_constraintTop_creator="1"
app:layout_constraintRight_toRightOf="@+id/activity_main_done"
android:layout_marginEnd="16dp"
tools:layout_constraintRight_creator="1"
app:layout_constraintBottom_toTopOf="@+id/discard"
android:layout_marginBottom="8dp"
tools:layout_constraintBottom_creator="1" />
</android.support.constraint.ConstraintLayout>
仅供引用 - 当我注释掉 android.support.constraint.Barrier 标签时，代码编译并运行。
最佳答案
Barrier 在 constraint-layout 库的 1.0.2 中不存在。它是 1.1.0 的一部分，目前处于测试阶段。您需要将依赖项切换回:
compile 'com.android.support.constraint:constraint-layout:1.1.0-beta1'
如果 Android Studio 提示找不到这个库，请确保您的项目级 build.gradle 文件看起来像the one from the project ，特别是在 allprojects 中配置了 Google 存储库:
allprojects {
repositories {
jcenter()
maven {
url 'https://maven.google.com'
}
}
}
关于android - 在包中找不到属性 'barrierDirection' 的资源标识符 - ConstraintLayout Barrier，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46017958/