Question

当尝试从Firebase数据库获取集合时，发生错误。

CollectionReference usersCollectionRef = database.collection("users");

错误：找不到显示出来的符号方法集合（字符串）错误

由于某种原因，它找不到.collection方法

Build.Gradle

apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.example.roguerun2"
        minSdkVersion 27
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.google.firebase:firebase-auth:16.0.5'
    implementation 'com.google.firebase:firebase-storage:16.0.4'
    implementation 'com.google.firebase:firebase-database:16.0.4'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.android.support:recyclerview-v7:28.0.0'
    implementation 'com.google.android.gms:play-services-maps:16.1.0'
    implementation 'com.google.android.gms:play-services-location:16.0.0'
    implementation 'pub.devrel:easypermissions:2.0.1'
    implementation 'com.google.maps:google-maps-services:0.2.4'
    implementation 'com.google.firebase:firebase-firestore:17.0.4'
    implementation 'com.google.firebase:firebase-core:16.0.9'



}
apply plugin: 'com.google.gms.google-services'

任何帮助都会得到

Answer 1

您正在混合使用Firestore和实时Firebase，如果您使用Firestore，则需要执行以下操作：

FirebaseFirestore database = FirebaseFirestore.getInstance();
CollectionReference usersCollectionRef = database.collection("users");

更多信息在这里：

https://firebase.google.com/docs/firestore/quickstart

尝试获取集合时，Android studio不会使.collection方法变灰

1 个答案: