a284628487/androidpoint

Android Note

AndroidPoint

androidpoint's Issues

ConstraintLayout

https://developer.android.com/reference/android/support/constraint/ConstraintLayout

OpenSL ES

面向 Android 的 OpenSL ES
https://developer.android.com/ndk/guides/audio/opensl-for-android
OpenSL ES 编程说明
https://developer.android.com/ndk/guides/audio/opensl-prog-notes
Android 扩展
https://developer.android.com/ndk/guides/audio/android-extensions#dynamic-interfaces
Getting Started
https://developer.android.com/ndk/guides/audio/opensl/getting-started

Manage your app's memory

https://developer.android.com/topic/performance/memory

Performance tips

https://developer.android.com/training/articles/perf-tips

AndroidStudio NDK

https://developer.android.com/studio/projects/add-native-code

Android Processor

修改AndroidManifest.xml

android.applicationVariants.all { variant ->
    variant.outputs.all { output ->
        output.processResources.doFirst { pm ->
            String manifestPath = output.processResources.manifestFile
            println "=====ManifestPath=====$manifestPath"
            // N:\xx\build\intermediates\merged_manifests\debug\AndroidManifest.xml
            def manifestContent = file(manifestPath).getText()
            def xml = new XmlParser().parseText(manifestContent)
            xml.application[0].appendNode("meta-data", ['android:name': 'channel', 'android:value': 'baidu'])
            def serialize = groovy.xml.XmlUtil.serialize(xml)
            file(manifestPath).write(serialize)
        }

        println "originalFileName: ${outputFileName}"
        outputFileName = "xxxxx.apk"
    }
}

GUP rendering

https://developer.android.com/studio/profile/inspect-gpu-rendering

Kotlin Coroutine & Flow

Flow

Flow.collect，每次执行 collect 都会触发flow提供者代码。

    @Test
    fun flowTest() {
        val flow = flow<String> {
            delay(1000)
            println("emit 1 ${this.hashCode()}")
            emit("${System.currentTimeMillis()}")
            delay(1000)
            println("emit 2 ${this.hashCode()}")
            emit("${System.currentTimeMillis()}")
        }
        runBlocking {
            val l = flow.take(1)
            println("------ take(1) collect 1 ------")
            l.collect()
            println("------ take(1) collect 2 ------")
            l.collect()

            println("------ collect 1 ------")
            flow.collect()
            println("------ collect 2 ------")
            flow.collect()

            println("------ Flow Collect End ------")
        }
    }

输出:

------ take(1) collect 1 ------
emit 1 398887205
------ take(1) collect 2 ------
emit 1 1121172875
------ collect 1 ------
emit 1 649734728
emit 2 649734728
------ collect 2 ------
emit 1 1595953398
emit 2 1595953398
------ Flow Collect End ------

Systrace

https://developer.android.com/studio/command-line/systrace

App Startup Time

https://developer.android.com/topic/performance/vitals/launch-time

EMPTY

Empty

Better performance through threading

https://developer.android.com/topic/performance/threads

Android Profiler

Android-Profiler: https://developer.android.com/studio/profile/android-profiler

1. Memory-Profiler: https://developer.android.com/studio/profile/memory-profiler
2. Cpu-Profiler: https://developer.android.com/studio/profile/cpu-profiler
3. Network-Profiler: https://developer.android.com/studio/profile/network-profiler

Android Unit Test

dependencies

    testImplementation "junit:junit:4.13.2"
    testImplementation "androidx.test:core:1.3.0"
    testImplementation "androidx.test:core-ktx:1.3.0"
    testImplementation "androidx.test.ext:junit:1.1.2"
    testImplementation "androidx.test.ext:junit-ktx:1.1.2"
    testImplementation "androidx.arch.core:core-testing:2.1.0"
    testImplementation "org.robolectric:robolectric:4.3.1"

Android Hilt

Component

ActivityComponent

定义ActivityComponent模块

interface IApi {

    fun sayHello()
}

class IApiImpl @Inject constructor(@ActivityContext private val context: Context) : IApi {

    override fun sayHello() {
        Log.e("IApiImpl${this.hashCode()}", "sayHello ${context}")
    }
}

@Module
@InstallIn(ActivityComponent::class)
abstract class ApiModule {

    @Binds
    abstract fun bindApi(apiImpl: IApiImpl): IApi
}

在Activity中注入

@AndroidEntryPoint
class TestActivity: AppCompatActivity() {

    @Inject lateinit var iApi: IApi
    @Inject lateinit var iApi2: IApi
}

class Test2Activity: AppCompatActivity() {

    @Inject lateinit var iApi: IApi
}

TestActivity和Test2Activity中获取到的IApi对象为不同的实例。
TestActivity中iApi和iApi2也是不同的实例对象。

SingletonComponent、Singleton

修改IApiImpl和ApiModule，将IApiImpl修改为单例实现。

@Singleton
class IApiImpl @Inject constructor(@ApplicationContext private val context: Context) : IApi {

    override fun sayHello() {
        Log.e("IApiImpl${this.hashCode()}", "sayHello ${context}")
    }
}

@Module
@InstallIn(SingletonComponent::class)
abstract class ApiModule {

    @Binds
    abstract fun bindApi(apiImpl: IApiImpl): IApi
}

ANR?

EMPTY