Android實戰之酷歐天氣（coolweather）開發遇到的一些坑

最近看《第一行代碼》的案例coolweather，就照着書上碼代碼了，因為版本原因，遇到了一些坑，記以留念

coolweather源碼：https://gitee.com/imoonfish/coolweather

遇到第一個問題是intent問題，軟件編譯，沒有問題，但是運行起來就閃退啊！logcat里面顯示的是intent傳輸的數據太大導致閃退，但是查看代碼，傳輸的明明就是幾個字節的數據，怎么會太大了！最后，尷尬的發現，沒有在AndroidManifest.xml里面注冊這個活動，我們在AndroidManifest.xml注冊該活動，添加如下代碼，問題解決！

<activity android:name=".WeatherActivity"/>

這里我inten跳轉的是WeatherActivity.class這個活動，所以這里寫的是WeatherActivity

遇到的第二個問題是 Android.Support.v4的問題，就是在寫xml界面時候，我們想要使用下滑刷新功能和側滑功能，書上用的是support.v4這個包，但是啊我們最新版本寫這個，它識別不出，顯示沒有這個包。查了資料發現，最新版本應該使用下面這兩個玩意兒！

androidx.drawerlayout.widget.DrawerLayout
​​​​​​​androidx.swiperefreshlayout.widget.SwipeRefreshLayout

 在activity_weather.xml中具體的xml界面如下：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary">

    <androidx.drawerlayout.widget.DrawerLayout

        android:id="@+id/drawer_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/bing_pic_img"
            android:scaleType="centerCrop"
            android:contentDescription="TODO" />

    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
        android:id="@+id/swipe_refresh"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="none"
        android:overScrollMode="never"
        android:id="@+id/weather_layout">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:fitsSystemWindows="true">
            <include layout="@layout/title"/>
            <include layout="@layout/now"/>
            <include layout="@layout/forecast"/>
            <include layout="@layout/aqi"/>
            <include layout="@layout/suggestion"/>
        </LinearLayout>

    </ScrollView>
    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>

        <fragment
            android:id="@+id/choose_area_fragment"
            android:name="com.moyu.coolweather.ChooseAreaFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="start"
            tools:layout="@layout/choose_area" />
    </androidx.drawerlayout.widget.DrawerLayout>

</FrameLayout>

然后在相關的java文件（WeatherActivity.class）里導入相應的包，問題解決

import androidx.drawerlayout.widget.DrawerLayout;
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;

 哦！還有添加依賴，Android Studio沒有自動幫你在build.gradle（Module:app)里面添加依賴的話，你需要手動添加

 implementation 'androidx.appcompat:appcompat:1.1.0-beta01'
 implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta2'

 附上這個項目build.gradle（Module:app)全部代碼：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion '29.0.0'
    defaultConfig {
        applicationId "com.moyu.coolweather"
        minSdkVersion 24
        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'
        }
    }
    compileOptions {
        sourceCompatibility = '1.8'
        targetCompatibility = '1.8'
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'org.litepal.android:java:3.0.0'
    implementation 'com.squareup.okhttp3:okhttp:4.0.0'
    implementation 'com.google.code.gson:gson:2.8.5'
    implementation 'com.github.bumptech.glide:glide:4.9.0'
    implementation 'androidx.appcompat:appcompat:1.1.0-beta01'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta2'
    testImplementation 'junit:junit:4.13-beta-3'
    androidTestImplementation 'androidx.test:runner:1.3.0-alpha01'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0-alpha01'
    implementation 'androidx.swiperefreshlayout:swiperefreshlayout:1.0.0'

}

 小技巧：你想要添加依賴的話，你知道這個依賴包的名字，你可以點擊File->Project Structure然后選擇你的app,點擊加號，添加Library Dependencies，搜索你要添加的依賴包即可，如圖所示：

最后一個問題是服務的問題，intent跳轉到服務，需要在AndroidManifest.xml里面配置相關服務如下：

        <service android:name=".service.AutoUpdateService">
            <intent-filter>
                <action android:name="AutoUpdateService"/>
            </intent-filter>
        </service>

這里我們跳轉的是AutoUpdateService服務，使用這個服務主要是在后台自動更新數據

這個啟動服務的代碼要寫在WeatherActivity.java文件的showWeatherInfo（Weather weather）{  }這個方法里面，最終項目方法中所有的代碼如下：

 /**
     * 處理並展示Weather實體類中的數據
     */
    private void showWeatherInfo(Weather weather){
        String cityName=weather.basic.cityName;
        String updateTime=weather.basic.update.updateTime.split(" ")[1];
        String degree=weather.now.temperature+"℃";
        String weatherInfo=weather.now.mroe.info;
        titleCity.setText(cityName);
        titleUpdateTime.setText(updateTime);
        degreeText.setText(degree);
        weatherInfoText.setText(weatherInfo);
        forecastLayout.removeAllViews();
        for(Forecast forecast:weather.forecastList){
            View view = LayoutInflater.from(this).inflate(R.layout.forecast_item,forecastLayout,false);
            TextView dateText=view.findViewById(R.id.date_text);
            TextView infoText=view.findViewById(R.id.info_text);
            TextView maxText=view.findViewById(R.id.max_text);
            TextView minText=view.findViewById(R.id.min_text);
            dateText.setText(forecast.date);
            infoText.setText(forecast.more.info);
            maxText.setText(forecast.temperature.max);
            minText.setText(forecast.temperature.min);
            forecastLayout.addView(view);
        }
        if(weather.aqi!=null){
            aqiText.setText(weather.aqi.city.aqi);
            pm25Text.setText(weather.aqi.city.pm25);
        }
        String comfort="舒適度："+weather.suggestion.comfort.info;
        String carWash="洗車指數："+weather.suggestion.carWash.info;
        String sport="運動建議："+weather.suggestion.sport.info;
        comfortText.setText(comfort);
        carWashText.setText(carWash);
        sportText.setText(sport);
        weatherLayout.setVisibility(View.VISIBLE);
        Intent intent=new Intent(this,AutoUpdateService.class);
        startService(intent);
    }

其他的代碼照着《第一行代碼》的內容敲就完事了！

注意：如果google源速度太慢，可以使用阿里雲鏡像倉庫，只需在build.gradle(Project:coolweather)里面添加阿里雲倉庫地址

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        maven{ url 'http://maven.aliyun.com/nexus/content/groups/public/' }
        google()
        jcenter()
        
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.4.1'
        
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
        maven { url 'http://maven.aliyun.com/nexus/content/repositories/jcenter' }
        maven { url 'http://maven.aliyun.com/nexus/content/repositories/google' }
        maven { url 'http://maven.aliyun.com/nexus/content/repositories/gradle-plugin' }
        google()
        jcenter()
        
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

整個項目AndroidManifest.xml最終配置如下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.moyu.coolweather">

    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:name="org.litepal.LitePalApplication"
        android:allowBackup="true"
        android:icon="@mipmap/logo"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".WeatherActivity"/>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name=".service.AutoUpdateService">
            <intent-filter>
                <action android:name="AutoUpdateService"/>
            </intent-filter>
        </service>
    </application>

</manifest>

 最后應用界面如下：