java - 我不断收到数据绑定(bind)错误，但不确定原因或如何修复它

Question

我目前正在开发一个天气应用程序，我正在将我的数据与从黑暗天空获得的 API 绑定(bind)。我的 gradle 将不再构建，我不断收到相同的错误，我几乎尝试了所有方法

我尝试重命名我的 ApplicationID ，我尝试重写整个代码并从头开始。我尝试过，我认为这可能是因为我的构建路径文件夹，或者我只是没有为类型变量调用正确的东西

这是我的 Activity_main.xml 代码，它显示了如何构建应用程序。

<?xml version="1.0" encoding="utf-8"?>
<layout
    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">
    <data>
        <variable
            name = "weather"
            type = "teamtreehouse.com.CurrentWeather" />
    </data>

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/appBackgroud"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/temperatureValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="8dp"
        android:text="@{String.valueOf(Math.round(weather.temperature))"
        android:textColor="@android:color/white"
        android:textSize="150sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.393"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.491" />

    <ImageView
        android:id="@+id/degreeImageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="35dp"
        app:layout_constraintStart_toEndOf="@+id/temperatureValue"
        app:layout_constraintTop_toTopOf="@+id/temperatureValue"
        app:srcCompat="@drawable/degree" />

    <TextView
        android:id="@+id/timeValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="8dp"
        android:text="@{`At ` + String.valueOf(weather.formattedTime) + ` it will be }"
        android:textColor="@color/half_white"
        android:textSize="18sp"
        app:layout_constraintBottom_toTopOf="@+id/temperatureValue"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <TextView
        android:id="@+id/locationValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="24dp"
        android:text="Alcatraz Island, CA"
        android:textColor="@android:color/white"
        android:textSize="24sp"
        app:layout_constraintBottom_toTopOf="@+id/timeValue"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <ImageView
        android:id="@+id/iconImageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="32dp"
        android:layout_marginLeft="32dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toBottomOf="@+id/locationValue"
        app:layout_constraintStart_toStartOf="parent"
        app:srcCompat="@drawable/cloudy_night" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="0.33" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="0.66" />

    <TextView
        android:id="@+id/humidityLabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="15dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:text="humidity"
        android:textColor="@color/half_white"
        app:layout_constraintEnd_toStartOf="@+id/guideline"
        app:layout_constraintStart_toStartOf="@+id/guideline"
        app:layout_constraintTop_toBottomOf="@+id/temperatureValue" />

    <TextView
        android:id="@+id/humidityValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="@{String.valueOf(weather.humidity)"
        android:textColor="@android:color/white"
        android:textSize="24sp"
        app:layout_constraintEnd_toEndOf="@+id/humidityLabel"
        app:layout_constraintStart_toStartOf="@+id/humidityLabel"
        app:layout_constraintTop_toBottomOf="@+id/humidityLabel" />

    <TextView
        android:id="@+id/precipLabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:text="Rain Snow?"
        android:textColor="@color/half_white"
        app:layout_constraintEnd_toStartOf="@+id/guideline2"
        app:layout_constraintStart_toStartOf="@+id/guideline2"
        app:layout_constraintTop_toBottomOf="@+id/temperatureValue" />

    <TextView
        android:id="@+id/precipValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="@{String.valueOf(Math.round(weather.precipChance * 100)) + `%}"
        android:textColor="@android:color/white"
        android:textSize="24sp"
        app:layout_constraintEnd_toEndOf="@+id/precipLabel"
        app:layout_constraintStart_toStartOf="@+id/precipLabel"
        app:layout_constraintTop_toBottomOf="@+id/precipLabel" />

    <TextView
        android:id="@+id/summary"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:text="@{weather.summary}"
        android:textColor="@android:color/white"
        android:textSize="18dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/precipValue" />

    <TextView
        android:id="@+id/darkSkyAttribution"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="159dp"
        android:layout_marginLeft="159dp"
        android:layout_marginEnd="193dp"
        android:layout_marginRight="193dp"
        android:layout_marginBottom="8dp"
        android:text="@string/dark_sky_messages"
        android:textColor="@color/half_white"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>
</layout>

这是我的主 Activity 类，其中发生一些数据绑定(bind):

package teamtreehouse.com;

import androidx.appcompat.app.AppCompatActivity;
import androidx.databinding.DataBindingUtil;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.text.method.LinkMovementMethod;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;

import org.jetbrains.annotations.NotNull;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import teamtreehouse.com.databinding.ActivityMainBinding;

public class MainActivity extends AppCompatActivity {

    public static  final String TAG = MainActivity.class.getSimpleName();

    private CurrentWeather currentWeather;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        final ActivityMainBinding binding  = DataBindingUtil.setContentView(MainActivity.this,
                R.layout.activity_main);

        TextView darkSky = findViewById(R.id.darkSkyAttribution);

        // connecting the link to the web
        darkSky.setMovementMethod(LinkMovementMethod.getInstance());

        String apiKey = "1a7a4d3a7acf106277ead1610e04637a";

        double latitude = 37.8267;

        double longitude = -122.4233;

        String forecastUrl = "https://api.darksky.net/forecast/"
                + apiKey + "/" + latitude +"," + longitude;
        if (isNetworkAvailable()) {

            OkHttpClient client = new OkHttpClient();

            Request request = new Request.Builder()
                    .url(forecastUrl)
                    .build();

            Call call = client.newCall(request);
            call.enqueue(new Callback() {
                @Override
                public void onFailure(@NotNull Call call, @NotNull IOException e) {

                }

                @Override
                public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                    try {
                        String jsonData = response.body().string();
                        Log.v(TAG, jsonData);
                        if (response.isSuccessful()) {
                            currentWeather = getCurrentDetails(jsonData);

                            CurrentWeather displayWeather = new CurrentWeather(
                                    currentWeather.getLocationLabel(),
                                    currentWeather.getIcon(),
                                    currentWeather.getTime(),
                                    currentWeather.getTemperature(),
                                    currentWeather.getHumidity(),
                                    currentWeather.getPrecipChance(),
                                    currentWeather.getSummary(),
                                    currentWeather.getTimeZone()

                            );

                            binding.setWeather(displayWeather);

                        } else {
                            alertUserAboutError();
                        }

                    } catch (IOException e) {
                        Log.e(TAG, "IO Exception caught: ", e);
                    }catch (JSONException e){
                        Log.e(TAG, "JSON Exception Caught: ", e);
                    }
                }
            });
        }
        Log.d(TAG, "Main UI code is running, hooray!");
    }

    private CurrentWeather getCurrentDetails(String jsonData) throws JSONException {

        JSONObject forecast = new JSONObject(jsonData);

        String timezone = forecast.getString("timezone");
        Log.i(TAG, "From Json: " + timezone);
        JSONObject currently = forecast.getJSONObject("currently");
        CurrentWeather currentWeather = new CurrentWeather();

        currentWeather.setHumidity(currently.getDouble("humidity"));
        currentWeather.setTime(currently.getLong("time"));
        currentWeather.setIcon(currently.getString("icon"));
        currentWeather.setLocationLabel("Alcatraz Island, CA");
        currentWeather.setPrecipChance(currently.getDouble("precipProbability"));
        currentWeather.setSummary(currently.getString("summary"));
        currentWeather.setTemperature(currently.getDouble("temperature"));
        currentWeather.setTimeZone(timezone);

        Log.d(TAG, currentWeather.getFormattedTime());

        return currentWeather;
    }

    private boolean isNetworkAvailable() {

        ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        boolean isAvailable = false;
        if(networkInfo != null && networkInfo.isConnected()){
            isAvailable = true;
        }
        else{
            Toast.makeText(this, R.string.network_unavaliable_message
             ,Toast.LENGTH_LONG).show();
        }
        return  isAvailable;
    }

    private void alertUserAboutError() {
        AlertDialogFragment dialog = new AlertDialogFragment();
        dialog.show(getFragmentManager(), "error_dialog");


    }
}

这是我的应用程序的 build.gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.1"
    defaultConfig {
        applicationId 'teamtreehouse.com.stormy'
        minSdkVersion 15
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    dataBinding{
        enabled = true
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.0.2'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation("com.squareup.okhttp3:okhttp:4.0.1")
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.2.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}

预期的结果是让我的 gradle 正确构建并绑定(bind)数据

这是我得到的错误代码:

Found data binding errors.
****/ data binding error ****msg:Syntax error: no viable alternative at input '<EOF>'
file:C:\Users\gstest\AndroidStudioProjects\Stormy\app\src\main\res\layout\activity_main.xml
loc:57:24 - 57:84
****\ data binding error ****

error: cannot find symbol class ActivityMainBindingImpl

Caused by: org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:compileDebugJavaWithJavac'.
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:95)
    at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:91)
    at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:57)
    at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:119)
    at org.gradle.api.internal.tasks.execution.ResolvePreviousStateExecuter.execute(ResolvePreviousStateExecuter.java:43)
    at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:93)
    at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:45)
    at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:94)
    at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:56)
    at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:55)
    at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:67)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:49)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:315)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:305)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:175)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:101)
    at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
    at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:49)
    at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:43)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:355)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:343)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:336)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:322)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:134)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:129)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:202)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:193)
    at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:129)
    ... 6 more
Caused by: java.lang.RuntimeException: android.databinding.tool.util.LoggedErrorException: Found data binding errors.
****/ data binding error ****msg:Syntax error: no viable alternative at input '<EOF>'
file:C:\Users\gstest\AndroidStudioProjects\Stormy\app\src\main\res\layout\activity_main.xml
loc:57:24 - 57:84
****\ data binding error ****

Answer 1

原来我只是缺少关闭 xml 文件中的消息的坟墓键 `