Question

我正在尝试从Firebase读取数据，但应用程序在以下logcat中生成错误时崩溃。我已经尝试了stackoverflow和其他站点上所有可用的解决方案，但仍然无法解决此问题，我进行了更改并在此处共享了必要的代码

.gradle项目（依赖项）

    dependencies {
                 classpath 'com.android.tools.build:gradle:3.3.2'
                 classpath 'com.google.gms:google-services:4.2.0'
                 }

app.gradle（依赖项）

    dependencies {
                 implementation fileTree(include: ['*.jar'], dir: 'libs')
                 implementation 'com.android.support:appcompat-v7:28.0.0'
                 implementation 'com.android.support:animated-vector-drawable:28.0.0'
                 implementation 'com.android.support.constraint:constraint-layout:1.1.3'
                 implementation 'com.google.firebase:firebase-database:17.0.0'
                implementation 'com.google.firebase:firebase-core:16.0.9'
                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:support-annotations:28.0.0'
            implementation 'com.android.support:support-v4:28.0.0'
   }

main.java

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        FirebaseApp.initializeApp(getApplicationContext());
        initViews();
        mBtn.setOnClickListener(this::readData);
    }

    public void readData(View view) {
        mRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                String data = dataSnapshot.getValue(String.class);
                setT.setText(data);
            }
            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {
                setT.setText("Sorry Data");
            }
        });
    }

    private void initViews() {
        mBtn = findViewById(R.id.mBtn);
        setT = findViewById(R.id.setT);
    }
}

Logcat

Answer 1

尝试将数据库实施版本17.0.0替换为此版本

    implementation 'com.google.firebase:firebase-database:16.0.5'

它将起作用

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1 个答案: