树莓派小车3——安卓客户端

 项目地址 https://github.com/ffmydream/WiCar

界面做的很难看，美工方面实在不在行。

重点是按钮触摸事件的处理，这里搬了RepeatListener项目代码，例如：

leftButton.setOnTouchListener(
RepeatListener(300, 300, //两个参数，第一个参数：首次响应延时，即第一次响应和第二次响应的间隔时间，第二个参数：从第二次响应后，以后每次响应间隔时间
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
ch.send("car:left:100:")
}
})
)

 为左转按钮绑定监听，检测到左转按钮被按下，每隔300ms，持续发送"car:left:100:"给另一个socket协程。

CoroutineScope(Dispatchers.IO).launch {
try {
val os = Socket("192.168.1.166", 50000).getOutputStream()
val pw = PrintWriter(os)
while (true) {
pw.write(ch.receive())
pw.flush()
}
} catch (e: Exception) {
} finally {
}
}

上面这个是和socket通信，没有数据发送的时候，协程被挂起在ch.receive()，接收到数据，使用pw.write发送到tcp服务器

package com.example.wicar
import android.annotation.SuppressLint
import android.content.pm.ActivityInfo
import android.os.Bundle
import android.util.Log
import android.view.View
import android.webkit.WebChromeClient
import android.webkit.WebSettings
import android.webkit.WebViewClient
import android.widget.CompoundButton
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main.*
import kotlinx.coroutines.*
import kotlinx.coroutines.channels.Channel
import java.io.PrintWriter
import java.net.Socket
object SrvAngle {
var hSrvAngle = 90
var vSrvAngle = 90
}
class MainActivity : AppCompatActivity() {
@SuppressLint("SetJavascriptEnabled")
override fun onCreate(savedInstanceState: Bundle?) {
requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val ch = Channel(0)
webView.settings.apply {
JavascriptEnabled = true
JavascriptCanOpenWindowsAutomatically = true
allowFileAccess = true // 设置允许访问文件数据
setSupportZoom(false)
builtInZoomCOntrols= true
cacheMode = WebSettings.LOAD_CACHE_ELSE_NETWORK
domStorageEnabled = true
databaseEnabled = true
useWideViewPort = true
loadWithOverviewMode = true
}
webView.webChromeClient = WebChromeClient()
webView.loadUrl("http://192.168.1.166:8081/")
camSwitch.setOnCheckedChangeListener { _, isChecked ->
CoroutineScope(Dispatchers.IO).launch {
if (isChecked) {
ch.send("cmd:sudo motion:0:")
} else {
ch.send("cmd:sudo pkill -KILL motion:0:")
}
}
}
CoroutineScope(Dispatchers.IO).launch {
try {
val os = Socket("192.168.1.166", 50000).getOutputStream()
val pw = PrintWriter(os)
while (true) {
pw.write(ch.receive())
pw.flush()
}
} catch (e: Exception) {
} finally {
}
}
leftButton.setOnTouchListener(
RepeatListener(300, 300,
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
ch.send("car:left:100:")
}
})
)
rightButton.setOnTouchListener(
RepeatListener(300, 300,
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
ch.send("car:right:100:")
}
})
)
forButton.setOnTouchListener(
RepeatListener(300, 300,
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
ch.send("car:for:100:")
}
})
)
backButton.setOnTouchListener(
RepeatListener(300, 300,
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
ch.send("car:back:100:")
}
})
)
srvLeftButton.setOnTouchListener(
RepeatListener(300, 50,
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
if (SrvAngle.hSrvAngle > 3)
SrvAngle.hSrvAngle = SrvAngle.hSrvAngle - 2
ch.send("srvo:horiz:${SrvAngle.hSrvAngle}:")
delay(5)
}
})
)
srvRightButton.setOnTouchListener(
RepeatListener(300, 50,
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
if (SrvAngle.hSrvAngle <177)
SrvAngle.hSrvAngle = SrvAngle.hSrvAngle + 2
ch.send("srvo:horiz:${SrvAngle.hSrvAngle}:")
delay(5)
}
})
)
srvUpButton.setOnTouchListener(
RepeatListener(300, 50,
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
if (SrvAngle.vSrvAngle <170)
SrvAngle.vSrvAngle = SrvAngle.vSrvAngle + 2
ch.send("srvo:vertic:${SrvAngle.vSrvAngle}:")
delay(5)
}
})
)
srvDownButton.setOnTouchListener(
RepeatListener(300, 50,
View.OnClickListener {
CoroutineScope(Dispatchers.IO).launch {
if (SrvAngle.vSrvAngle > 60)
SrvAngle.vSrvAngle = SrvAngle.vSrvAngle - 2
ch.send("srvo:vertic:${SrvAngle.vSrvAngle}:")
delay(5)
}
})
)
srvInitButton.setOnClickListener() {
CoroutineScope(Dispatchers.IO).launch {
ch.send("srv:init:0:")
}
}
}
}

本文地址：https://blog.csdn.net/ffmydream/article/details/108140128