# 冷啟動(dòng)測(cè)量（先停止應(yīng)用）
adb shell am force-stop com.example.app
adb shell am start-activity -W -n com.example.app/.MainActivity

# 輸出示例
Starting: Intent { cmp=com.example.app/.MainActivity }
Status: ok
LaunchState: COLD
Activity: com.example.app/.MainActivity
TotalTime: 856
WaitTime: 872
Complete

#!/bin/bash
package="com.example.app"
activity="com.example.app.MainActivity"
iterations=10

echo "開始冷啟動(dòng)測(cè)試($iterations次循環(huán))..."
total=0

for ((i=1; i<=$iterations; i++))
do
  adb shell am force-stop $package
  sleep 1  # 確保應(yīng)用完全停止
  
  # 獲取TotalTime
  result=$(adb shell am start-activity -W -n $package/$activity | grep "TotalTime")
  time_ms=$(echo $result | cut -d' ' -f2)
  
  # 過(guò)濾無(wú)效結(jié)果
  if [[ $time_ms =~ ^[0-9]+$ ]]; then
    echo "第$i次: ${time_ms}ms"
    total=$((total + time_ms))
  else
    echo "第$i次: 測(cè)量失敗"
    ((i--))  # 重試
  fi
done

average=$((total / iterations))
echo "--------------------------------"
echo "平均啟動(dòng)時(shí)間: ${average}ms"

# 啟動(dòng)應(yīng)用后返回桌面
adb shell input keyevent KEYCODE_HOME

# 再次啟動(dòng)（熱啟動(dòng)）
adb shell am start-activity -W -n com.example.app/.MainActivity

class MyApp : Application() {
    companion object {
        var appStartTime: Long = 0
    }

    override fun onCreate() {
        super.onCreate()
        appStartTime = SystemClock.uptimeMillis()
    }
}

class MainActivity : AppCompatActivity() {
    
    override fun onResume() {
        super.onResume()
        val launchTime = SystemClock.uptimeMillis() - MyApp.appStartTime
        Log.d("LaunchTime", "冷啟動(dòng)耗時(shí): ${launchTime}ms")
    }
}

class MainActivity : AppCompatActivity() {

    override fun onStart() {
        super.onStart()
        
        // 當(dāng)內(nèi)容完全加載后調(diào)用
        window.decorView.post {
            reportFullyDrawn()
        }
    }
}

adb logcat -s ActivityManager | grep "Fully drawn"

object LaunchTracker {
    const val TAG = "LaunchTracker"
    
    // 啟動(dòng)階段定義
    var appCreateTime = 0L
    var activityCreateTime = 0L
    var windowFocusedTime = 0L
    var fullyDrawnTime = 0L
    
    fun logAppCreate() {
        appCreateTime = SystemClock.uptimeMillis()
    }
    
    fun logActivityCreate() {
        activityCreateTime = SystemClock.uptimeMillis()
        Log.d(TAG, "Application初始化耗時(shí): ${activityCreateTime - appCreateTime}ms")
    }
    
    fun logWindowFocused() {
        windowFocusedTime = SystemClock.uptimeMillis()
        Log.d(TAG, "Activity創(chuàng)建耗時(shí): ${windowFocusedTime - activityCreateTime}ms")
    }
    
    fun logFullyDrawn() {
        fullyDrawnTime = SystemClock.uptimeMillis()
        Log.d(TAG, "窗口焦點(diǎn)到完全繪制耗時(shí): ${fullyDrawnTime - windowFocusedTime}ms")
        Log.d(TAG, "總啟動(dòng)耗時(shí): ${fullyDrawnTime - appCreateTime}ms")
    }
}

// 在Application中
class MyApp : Application() {
    override fun onCreate() {
        super.onCreate()
        LaunchTracker.logAppCreate()
    }
}

// 在Activity中
class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        LaunchTracker.logActivityCreate()
    }
    
    override fun onWindowFocusChanged(hasFocus: Boolean) {
        super.onWindowFocusChanged(hasFocus)
        if (hasFocus) LaunchTracker.logWindowFocused()
    }
    
    // 在內(nèi)容完全繪制后調(diào)用
    fun onContentDrawn() {
        LaunchTracker.logFullyDrawn()
    }
}

dependencies {
    implementation "androidx.startup:startup-runtime:1.2.0-alpha02"
}

class AnalyticsInitializer : Initializer<Unit> {
    private val startTime = SystemClock.uptimeMillis()

    override fun create(context: Context) {
        // 模擬初始化工作
        Thread.sleep(50) 
        val cost = SystemClock.uptimeMillis() - startTime
        Log.d("AppStartup", "Analytics初始化耗時(shí): ${cost}ms")
    }

    override fun dependencies(): List<Class<out Initializer<*>>> {
        // 聲明依賴關(guān)系
        return listOf(NetworkInitializer::class.java)
    }
}

class NetworkInitializer : Initializer<Unit> {
    private val startTime = SystemClock.uptimeMillis()

    override fun create(context: Context) {
        // 模擬網(wǎng)絡(luò)庫(kù)初始化
        Thread.sleep(80)
        val cost = SystemClock.uptimeMillis() - startTime
        Log.d("AppStartup", "Network初始化耗時(shí): ${cost}ms")
    }

    override fun dependencies() = emptyList<Class<out Initializer<*>>>()
}

<provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    android:exported="false">
    
    <meta-data
        android:name="com.example.initializers.AnalyticsInitializer"
        android:value="androidx.startup" />
        
    <meta-data
        android:name="com.example.initializers.NetworkInitializer"
        android:value="androidx.startup" />
</provider>

// 手動(dòng)初始化組件
AppInitializer.getInstance(this)
    .initializeComponent(AnalyticsInitializer::class.java)

// 延遲初始化（在后臺(tái)線程）
val executor = Executors.newSingleThreadExecutor()
executor.execute {
    AppInitializer.getInstance(this)
        .initializeComponent(NetworkInitializer::class.java)
}

class MyApp : Application() {

    private val appExecutor by lazy { 
        Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors()) 
    }

    override fun onCreate() {
        super.onCreate()
        
        // 主線程必要初始化
        initCrashReporting()
        
        // 后臺(tái)線程延遲初始化
        appExecutor.execute {
            initAnalytics()
            initPushService()
        }
    }
    
    private fun initCrashReporting() {
        // 必須立即初始化的組件
    }
    
    private fun initAnalytics() {
        // 三方分析庫(kù)初始化
    }
    
    private fun initPushService() {
        // 推送服務(wù)初始化
    }
}

<androidx.constraintlayout.widget.ConstraintLayout>
    
    <!-- 使用ViewStub延遲加載 -->
    <ViewStub
        android:id="@+id/stub_ads"
        android:layout="@layout/ads_banner"
        app:layout_constraintTop_toTopOf="parent" />
    
    <!-- 優(yōu)先顯示的核心內(nèi)容 -->
    <TextView
        android:id="@+id/welcomeText"
        android:text="歡迎使用應(yīng)用"
        ... />
    
    <!-- 使用占位控件 -->
    <include layout="@layout/placeholder_footer" />

</androidx.constraintlayout.widget.ConstraintLayout>

class MainActivity : AppCompatActivity() {
    
    override fun onStart() {
        super.onStart()
        
        // 延遲加載非必要視圖
        Handler(Looper.getMainLooper()).postDelayed({
            val stub = findViewById<ViewStub>(R.id.stub_ads)
            stub?.inflate()
        }, 1000)
    }
}

androidTestImplementation "androidx.benchmark:benchmark-macro-junit4:1.2.0"

@RunWith(AndroidJUnit4::class)
class StartupBenchmark {
    
    @get:Rule
    val benchmarkRule = MacrobenchmarkRule()
    
    @Test
    fun startup() = benchmarkRule.measureRepeated(
        packageName = "com.example.app",
        metrics = listOf(StartupTimingMetric()),
        iterations = 10,
        setupBlock = {
            // 每次測(cè)試前停止應(yīng)用
            pressHome()
        }
    ) {
        // 啟動(dòng)應(yīng)用
        startActivityAndWait()
    }
}

adb shell perfetto --config :test --out /data/misc/perfetto-traces/trace

class LaunchMonitor private constructor() {
    
    companion object {
        @Volatile private var instance: LaunchMonitor? = null
        
        fun get() = instance ?: synchronized(this) {
            instance ?: LaunchMonitor().also { instance = it }
        }
    }
    
    private var appStartTime = 0L
    private var activityStartTime = 0L
    private var fullyDrawnTime = 0L
    
    fun recordAppStart() {
        appStartTime = SystemClock.uptimeMillis()
    }
    
    fun recordActivityStart() {
        activityStartTime = SystemClock.uptimeMillis()
    }
    
    fun recordFullyDrawn() {
        fullyDrawnTime = SystemClock.uptimeMillis()
        uploadMetrics()
    }
    
    private fun uploadMetrics() {
        val totalTime = fullyDrawnTime - appStartTime
        val initTime = activityStartTime - appStartTime
        val uiTime = fullyDrawnTime - activityStartTime
        
        // 上報(bào)到監(jiān)控平臺(tái)
        Firebase.analytics.logEvent("launch_time", bundleOf(
            "total" to totalTime,
            "init" to initTime,
            "ui" to uiTime
        ))
    }
}

// 在Application中
class MyApp : Application() {
    override fun onCreate() {
        super.onCreate()
        LaunchMonitor.get().recordAppStart()
    }
}

// 在Activity中
class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        LaunchMonitor.get().recordActivityStart()
    }
    
    override fun onStart() {
        super.onStart()
        window.decorView.post {
            // 確保內(nèi)容完全加載
            LaunchMonitor.get().recordFullyDrawn()
        }
    }
}