Question

我每天都面临着在我的项目中非常令人沮丧的ConstraintLayout问题。

项目gradle文件：

buildscript {

    ext.support_library_version = '27.0.2'
    ext.play_services_version = '11.6.2'
    ext.firebase_version = '11.6.2'

    repositories {
        jcenter()
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
        classpath 'io.realm:realm-gradle-plugin:4.2.0'
        classpath 'com.google.gms:google-services:3.1.2'

        classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.7.3'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
        google()
        maven { url "https://maven.google.com" }
        maven { url 'https://jitpack.io' }
    }
}

这是我的app gradle的简短版本：

apply plugin: 'com.android.library'
apply plugin: 'realm-android'

// set to 'cmake', 'none'
def nativeBuildSystem = 'none'//'cmake'

realm {
    syncEnabled = false
}

android {
    defaultConfig {
        targetSdkVersion 27
        compileSdkVersion 27
        minSdkVersion 21
        // for using vectors for less than 21 API
        vectorDrawables.useSupportLibrary = true

        versionCode 56
        dexOptions {
            preDexLibraries true
            javaMaxHeapSize "4g"
        }

        // Enabling multidex support.
        multiDexEnabled true
        versionName "1.6.5"

        renderscriptTargetApi 2
        renderscriptSupportModeEnabled true    // Enable RS support

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

configurations {
    all*.exclude group: 'commons-logging', module: 'commons-logging'
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')

    /*********************************  Deep Linking Library *********************************************/
    api 'com.airbnb:deeplinkdispatch:3.1.1'
    annotationProcessor 'com.airbnb:deeplinkdispatch-processor:3.1.1'

    /*********************************    Android SDK  *********************************************/
    api "com.android.support:appcompat-v7:$support_library_version"
    api 'com.android.support.constraint:constraint-layout:1.0.2'
    api "com.android.support:percent:$support_library_version"
    api "com.android.support:recyclerview-v7:$support_library_version"
    api "com.android.support:gridlayout-v7:$support_library_version"
    api "com.android.support:cardview-v7:$support_library_version"
    api "com.android.support:design:$support_library_version"
    api "com.android.support:support-vector-drawable:$support_library_version"
    api "com.android.support:support-core-utils:$support_library_version"
    api 'com.android.support:multidex:1.0.2'

}

我在布局编辑器中看到的内容：

在我的xml下面：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

</android.support.constraint.ConstraintLayout>

在这种情况下，

布局编辑器说：

如果我点击显示例外，我会看到：

java.lang.NegativeArraySizeException
at android.support.constraint.R$styleable.<clinit>(Unknown Source)
at android.support.constraint.ConstraintLayout.init(ConstraintLayout.java:440)
at android.support.constraint.ConstraintLayout.<init>(ConstraintLayout.java:420)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.jetbrains.android.uipreview.ViewLoader.createNewInstance(ViewLoader.java:481)
at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:264)
at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:222)
at com.android.tools.idea.rendering.LayoutlibCallbackImpl.loadView(LayoutlibCallbackImpl.java:211)
at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:337)
at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:348)
at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:248)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
at android.view.LayoutInflater.inflate(LayoutInflater.java:394)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:325)
at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:384)
at com.android.tools.idea.layoutlib.LayoutLibrary.createSession(LayoutLibrary.java:193)
at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:547)
at com.android.tools.idea.rendering.RenderTask.lambda$inflate$3(RenderTask.java:681)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

为了解决问题我尝试了很多但没有成功。我没有解决使用简单的方法，如无效缓存/清理项目/重建项目等...

Answer 1

<强>问题：
如果您在 attr.xml 中定义的一个<declare-stylable>标记中包含太多属性，布局编辑器似乎会遇到一些麻烦！

<强>解决方案：
我在一个<declare-stylable>代码中有 49 属性如果我删除 4 属性，那么我 45 ，布局编辑器正在运行。

我还在Google Issue Tracker上添加了一个问题：
https://issuetracker.google.com/issues/71641021

Google问题更新
这已针对Android Studio 3.1版本进行了修复。

Answer 2

请勿使用"use strict"; var db = require('./db'); exports.handler = (event, context, callback) => { db.connect(function (conn) { if (conn == null) { console.log("Database connection failed: "); callback("Error", "Database connection failed"); } else { console.log('Connected to database.'); conn.query("INSERT INTO employee(name,salary) VALUE(?,?)",['Joe',8000], function(err,res){ if(err) throw err; else { console.log('A new employee has been added.'); } }); db.getConnection().end(); callback(null, "Database connection done"); } }); };，而应使用ConstraintLayout或Relative...。这应该有用。

Linear...

约束布局。渲染问题。布局编辑器

2 个答案: