「Android 自定义 View」—— AreaSelectL

作者: SkyRiN | 来源:发表于2018-12-21 10:10 被阅读1次

前几天写了一个小工具，其中一个设置项需要屏幕区域范围坐标参数，由于通过观察直接填写坐标信息不太现实，于是就有了通过直接拖拽屏幕去取这个参数的需求，又因为需要在任意界面都能选取，所以就想到了悬浮窗，这里以前写过一个悬浮窗工具类《FloatWindowUtils 实现及事件冲突解决详解》，想着再加一些手势及绘制应该就能实现，于是吭叽吭叽搞了半天，发现其中还是有些坑的，所以在此记录备忘。

效果图和用法如下：

未命名.gif

如上图，这个 View 的功能很简单，就是在屏幕上弹出一个全屏悬浮窗遮罩，然后在上面拖拽选择区域，最后保存坐标信息就好了。

详细实现我就不讲了，后面会贴源码，这里主要讲一下实现思路和几个需要注意的点

实现思路

继承 View 还是 ViewGroup

由于悬浮窗里需要有提示文字以及取消和保存两个按钮，所以我没有直接去继承 View 来写，直接继承 View 来实现当然也可以，但是需要把下面的文字以及按钮都画出来，可能还需要内置按钮的触发回调等等业务，最终我选择了继承 ViewGroup(ConstrainsLayout) 来实现，这样做可以共享 ConstrainsLayout 的所有属性。和直接继承 View 实现相比，它的优点就是可以在布局文件中方便的添加子 View，缺点是集成度不够高，需要引用外部资源，所以具体实现可以看使用场景，这里没有复用的场景，集成度要求不高，所以就选择了更简单的继承 ViewGroup 来实现。

class AreaSelectLayout : ConstraintLayout {
    constructor(context: Context) : super(context) {}
    constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {}
    
    override fun onDraw(canvas: Canvas) {
        super.onDraw(canvas)
    }

    @SuppressLint("ClickableViewAccessibility")
    override fun onTouchEvent(event: MotionEvent): Boolean {
        return super.onTouchEvent(event)
    }
}

<?xml version="1.0" encoding="utf-8"?>
<com.example.area_select_layout.AreaSelectLayout
    ...
    android:background="@color/half_trans">

    <ImageButton
        android:id="@+id/btn_save"
        ... />

    <ImageButton
        android:id="@+id/btn_cancel"
        ... />

    <LinearLayout ...>
        <TextView
            android:id="@+id/textView4"
            android:text="拖动选取"
            ... />

        <TextView
            android:id="@+id/textView5"
            android:text="起始"
            ... />

        <TextView
            android:text="和"
            ... />

        <TextView
            android:text="结束"
            ... />

        <TextView
            android:text="区域"
            ... />
    </LinearLayout>

</com.example.area_select_layout.AreaSelectLayout>

跟随手指移动绘制方框

区域选择，其实就是在屏幕上画对角线，手指落下，记录起点，手指移动，不断更新终点并通知 Canvas 画出来，手指抬起，保存最终坐标。这里需要注意的是 Y 坐标要减去 StatusBar 的高度。

@SuppressLint("ClickableViewAccessibility")
override fun onTouchEvent(event: MotionEvent): Boolean {
    when (event.action) {
        MotionEvent.ACTION_DOWN -> {
            // 记录起点位置
            setStartPos(event.rawX.toInt(), (event.rawY - statusBarHeight).toInt())
        }
        MotionEvent.ACTION_MOVE -> {
            // 更新终点位置
            setStopPos(event.rawX.toInt(), (event.rawY - statusBarHeight).toInt())
            // 使布局失效，让系统触发 onDraw 重绘界面
            invalidate()
        }
    }
    return super.onTouchEvent(event)
}

位置存储以及方向判断

由于位置总共有四个点，八个坐标值，用变量来存很不便，所以我直接用 Rect 来存了，一是便于管理，可以用这些值方便的判断正在选区起始区域或是结束区域，二是可以直接通过 Canvas.drawRect(Rect, Paint) 来绘制方框了。

private fun setStartPos(rawX: Int, rawY: Int) {
    // 起始区域已经绘制
    if (startRect.bottom != 0) {
        startSelected = true
    }
    // 如果存在两个选区的话，则清屏重绘制
    if (startRect.bottom != 0 && endRect.bottom != 0) {
        clear()
    }
    // 判断落点属于起始区域还是结束区域
    if (startSelected) {
        end.x = rawX
        end.y = rawY
    } else {
        start.x = rawX
        start.y = rawY
    }
}
private fun setStopPos(rawX: Int, rawY: Int) {
    // 判断终点属于起始区域还是结束区域
    if (startSelected) {
        // rawX < end.x 表示从左向右拖动 ⇨
        // ⇨ 时 x 更新 right，y 同理
        endRect.left = if (rawX < end.x) rawX else end.x
        // rawX > end.x 表示从右向左拖动 ⇦
        // ⇦ 时 x 更新 left，y 同理
        endRect.right = if (rawX > end.x) rawX else end.x
        endRect.top = if (rawY < end.y) rawY else end.y
        endRect.bottom = if (rawY > end.y) rawY else end.y
    } else {
        startRect.left = if (rawX < start.x) rawX else start.x
        startRect.right = if (rawX > start.x) rawX else start.x
        startRect.top = if (rawY < start.y) rawY else start.y
        startRect.bottom = if (rawY > start.y) rawY else start.y
    }
}

使布局悬浮在应用之外

这块考虑了一下，最后还是没有用 FloatWindowUtils，因为就一个布局，了解了悬浮窗怎么玩之后，悬浮起一个布局也很简单，直接用 WindowManager 十几行代码搞定了。

private fun showSelectLayout() {
    if (!SystemSetings.isAppOpsOn(this)) {
        SystemSetings.openOpsSettings(this)
        Toast.makeText(this,"请先开启悬浮窗权限",Toast.LENGTH_SHORT).show()
        return
    }
    wm = getSystemService(Context.WINDOW_SERVICE) as WindowManager
    val lp = WindowManager.LayoutParams()
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        lp.type = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY
    } else {
        lp.type = WindowManager.LayoutParams.TYPE_PHONE
    }
    lp.format = PixelFormat.TRANSLUCENT
    lp.flags = lp.flags or WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
    lp.width = WindowManager.LayoutParams.MATCH_PARENT
    lp.height = WindowManager.LayoutParams.MATCH_PARENT
    lp.gravity = Gravity.END or Gravity.TOP
    if (selectLayout.parent!=null){
        wm.removeView(selectLayout)
    }
    wm.addView(selectLayout, lp)
}

核心部分基本就是上面这些了，算位置的时候稍微有点绕但是不难，多分析下就出来了，下面贴下源码

项目源码

manifests.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.area_select_layout">
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

MainActivity.kt

class MainActivity : AppCompatActivity() {
    private lateinit var selectLayout: AreaSelectLayout
    private lateinit var btnSave: View
    private lateinit var btnCancel: View
    private lateinit var wm: WindowManager
    @SuppressLint("SetTextI18n")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        selectLayout = View.inflate(this,R.layout.dialog_select_layout,null) as AreaSelectLay
        btnSave = selectLayout.findViewById(R.id.btn_save)
        btnCancel = selectLayout.findViewById(R.id.btn_cancel)
        btnSave.setOnClickListener {
            hideSelectLayout()
            val startRect = selectLayout.getStartRect()
            val endRect = selectLayout.getEndRect()
            textView.text = "start-area:[${startRect.left},${startRect.top}]," +
                    "[${startRect.right},${startRect.bottom}]" +
                    "\n" +
                    "end-area:[${endRect.left},${endRect.top}]," +
                    "[${endRect.right},${endRect.bottom}]"
        }
        btnCancel.setOnClickListener {
            hideSelectLayout()
            selectLayout.clear()
        }
        button.setOnClickListener {
            showSelectLayout()
        }
    }
    private fun hideSelectLayout() {
        wm.removeView(selectLayout)
    }
    private fun showSelectLayout() {
        if (!SystemSetings.isAppOpsOn(this)) {
            SystemSetings.openOpsSettings(this)
            Toast.makeText(this,"请先开启悬浮窗权限",Toast.LENGTH_SHORT).show()
            return
        }
        // 设置位置
        wm = getSystemService(Context.WINDOW_SERVICE) as WindowManager
        val lp = WindowManager.LayoutParams()
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            lp.type = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY
        } else {
            lp.type = WindowManager.LayoutParams.TYPE_PHONE
        }
        lp.format = PixelFormat.TRANSLUCENT
        lp.flags = lp.flags or WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
        lp.width = WindowManager.LayoutParams.MATCH_PARENT
        lp.height = WindowManager.LayoutParams.MATCH_PARENT
        lp.gravity = Gravity.END or Gravity.TOP
        if (selectLayout.parent!=null){
            wm.removeView(selectLayout)
        }
        wm.addView(selectLayout, lp)
    }
}

AreaSelectLayout.kt

class AreaSelectLayout : ConstraintLayout {
    private var paint = Paint(Paint.ANTI_ALIAS_FLAG)
    private var endPaint = Paint(Paint.ANTI_ALIAS_FLAG)
    private var paintText = Paint(Paint.ANTI_ALIAS_FLAG)
    /**
     * 滑动范围
     */
    private var startRect = Rect()
    private var endRect = Rect()
    /**
     * 坐标文字边框
     */
    private var ltStrBounds = Rect()
    private var rbStrBounds = Rect()
    private var start = Point()
    private var end = Point()
    private var startSelected = false
    private val statusBarHeight: Int
        get() {
            val resourceId = resources.getIdentifier("status_bar_height", "dimen", "android")
            return resources.getDimensionPixelSize(resourceId)
        }
    constructor(context: Context) : super(context) {}
    constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {}
    init {
        paint.strokeWidth = dp2px(2f)
        paint.style = Paint.Style.STROKE
        paint.color = Color.parseColor("#1aad19")
        endPaint.strokeWidth = dp2px(2f)
        endPaint.style = Paint.Style.STROKE
        endPaint.color = Color.parseColor("#f45454")
        paintText.textSize = dp2px(12f)
        paintText.color = Color.parseColor("#1aad19")
    }
    override fun onDraw(canvas: Canvas) {
        super.onDraw(canvas)
        // 绘制结束区域
        canvas.drawRect(endRect, endPaint)
        // 绘制起始区域
        canvas.drawRect(startRect, paint)
    }
    @SuppressLint("ClickableViewAccessibility")
    override fun onTouchEvent(event: MotionEvent): Boolean {
        when (event.action) {
            MotionEvent.ACTION_DOWN -> {
                setStartPos(event.rawX.toInt(), (event.rawY - statusBarHeight).toInt())
            }
            MotionEvent.ACTION_MOVE -> {
                setStopPos(event.rawX.toInt(), (event.rawY - statusBarHeight).toInt())
                invalidate()
            }
        }
        return super.onTouchEvent(event)
    }
    private fun setStartPos(rawX: Int, rawY: Int) {
        if (startRect.bottom != 0) {
            startSelected = true
        }
        if (startRect.bottom != 0 && endRect.bottom != 0) {
            clear()
        }
        if (startSelected) {
            end.x = rawX
            end.y = rawY
        } else {
            start.x = rawX
            start.y = rawY
        }
    }
    private fun setStopPos(rawX: Int, rawY: Int) {
        if (startSelected) {
            endRect.left = if (rawX < end.x) rawX else end.x
            endRect.right = if (rawX > end.x) rawX else end.x
            endRect.top = if (rawY < end.y) rawY else end.y
            endRect.bottom = if (rawY > end.y) rawY else end.y
        } else {
            startRect.left = if (rawX < start.x) rawX else start.x
            startRect.right = if (rawX > start.x) rawX else start.x
            startRect.top = if (rawY < start.y) rawY else start.y
            startRect.bottom = if (rawY > start.y) rawY else start.y
        }
    }
    fun clear() {
        startSelected = false
        startRect.top = 0
        startRect.bottom = 0
        startRect.left = 0
        startRect.right = 0
        endRect.top = 0
        endRect.bottom = 0
        endRect.left = 0
        endRect.right = 0
        invalidate()
    }
    fun setStartRect(rect: Rect) {
        this.startRect = rect
    }
    fun getStartRect(): Rect {
//        val rstRect = startRect
//        rstRect.top += statusBarHeight
//        rstRect.bottom += statusBarHeight
        return startRect
    }
    fun setEndRect(rect: Rect) {
        this.endRect = rect
    }
    fun getEndRect(): Rect {
//        val rstRect = endRect
//        rstRect.top += statusBarHeight
//        rstRect.bottom += statusBarHeight
        return endRect
    }
    fun dp2px(dp: Float): Float {
        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, Resources.getSystem().displayMetrics)
    }
}

SystemSetings.kt

/**
 * Created by skyrin on 2016/9/25.
 * 系统设置相关
 */
object SystemSetings {
    /**
     * 辅助服务是否开启
     * @param context
     * @return true if Accessibility is on.
     */
    fun isAccessibilitySettingsOn(context: Context): Boolean {
        var i: Int
        try {
            i = Settings.Secure.getInt(context.contentResolver, "accessibility_enabled")
        } catch (e: Settings.SettingNotFoundException) {
            Log.i("AccessibilitySettingsOn", e.message)
            i = 0
        }
        if (i != 1) {
            return false
        }
        val string = Settings.Secure.getString(context.contentResolver, "enabled_accessibility_services")
        return string?.toLowerCase()?.contains(context.packageName.toLowerCase()) ?: false
    }
    /**
     * 打开辅助服务的设置
     */
    fun openAccessibilityServiceSettings(context: Context): Boolean {
        var result = true
        try {
            val intent = Intent(Settings.ACTION_ACCESSIBILITY_SETTINGS)
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
            context.startActivity(intent)
        } catch (e: Exception) {
            result = false
            e.printStackTrace()
        }
        return result
    }
    /** 打开通知栏设置 */
    @TargetApi(Build.VERSION_CODES.LOLLIPOP_MR1)
    fun openNotificationServiceSettings(context: Context) {
        try {
            val intent = Intent(Settings.ACTION_NOTIFICATION_LISTENER_SETTINGS)
            context.startActivity(intent)
        } catch (e: Exception) {
            e.printStackTrace()
        }
    }
    /**
     * 打开app权限的设置
     * @param context
     * @return
     */
    fun openFloatWindowSettings(context: Context): Boolean {
        try {
            val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)
            val uri = Uri.fromParts("package", context.packageName, null)
            intent.data = uri
            context.startActivity(intent)
        } catch (e: Exception) {
            e.printStackTrace()
            return false
        }
        return true
    }
    /**
     * 打开app权限的设置
     * @param context
     * @return
     */
    fun openFloatWindowSettings(context: Context, pkgName: String): Boolean {
        try {
            val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)
            val uri = Uri.fromParts("package", pkgName, null)
            intent.data = uri
            context.startActivity(intent)
        } catch (e: Exception) {
            e.printStackTrace()
            return false
        }
        return true
    }
    /**
     * 打开悬浮窗设置页
     * 部分第三方ROM无法直接跳转可使用[.openAppSettings]跳到应用详情页
     *
     * @param context
     * @return true if it's open successful.
     */
    fun openOpsSettings(context: Context): Boolean {
        try {
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {
                val intent = Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION, Uri.parse("package:" + context.packageName))
                context.startActivity(intent)
            } else {
                return openAppSettings(context)
            }
        } catch (e: Exception) {
            e.printStackTrace()
            return false
        }
        return true
    }
    /**
     * 打开应用详情页
     *
     * @param context
     * @return true if it's open success.
     */
    fun openAppSettings(context: Context): Boolean {
        try {
            val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)
            val uri = Uri.fromParts("package", context.packageName, null)
            intent.data = uri
            context.startActivity(intent)
        } catch (e: Exception) {
            e.printStackTrace()
            return false
        }
        return true
    }
    /**
     * 判断 悬浮窗口权限是否打开
     * 由于android未提供直接跳转到悬浮窗设置页的api，此方法使用反射去查找相关函数进行跳转
     * 部分第三方ROM可能不适用
     *
     * @param context
     * @return true 允许  false禁止
     */
    fun isAppOpsOn(context: Context): Boolean {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            return Settings.canDrawOverlays(context)
        }
        try {
            val `object` = context.getSystemService(Context.APP_OPS_SERVICE) ?: return false
            val localClass = `object`.javaClass
            val arrayOfClass = arrayOfNulls<Class<*>>(3)
            arrayOfClass[0] = Integer.TYPE
            arrayOfClass[1] = Integer.TYPE
            arrayOfClass[2] = String::class.java
            val method = localClass.getMethod("checkOp", *arrayOfClass) ?: return false
            val arrayOfObject1 = arrayOfNulls<Any>(3)
            arrayOfObject1[0] = 24
            arrayOfObject1[1] = Binder.getCallingUid()
            arrayOfObject1[2] = context.packageName
            val m = method.invoke(`object`, *arrayOfObject1) as Int
            return m == AppOpsManager.MODE_ALLOWED
        } catch (ex: Exception) {
            ex.stackTrace
        }
        return false
    }
    /**
     * 启动app
     *
     * @param context
     * @param pkgName 包名
     * @return 是否启动成功
     */
    fun startApp(context: Context, pkgName: String): Boolean {
        try {
            val manager = context.packageManager
            val openApp = manager.getLaunchIntentForPackage(pkgName) ?: return false
            openApp.flags = Intent.FLAG_ACTIVITY_SINGLE_TOP
            context.startActivity(openApp)
        } catch (e: Exception) {
            return false
        }
        return true
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="160dp"
        android:text="选择区域"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent" />
    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="80dp"
        android:text="TextView"
        app:layout_constraintBottom_toTopOf="@+id/button"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />
</android.support.constraint.ConstraintLayout>

dialog_select_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<com.example.area_select_layout.AreaSelectLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:background="@color/half_trans">
    <ImageButton
        android:id="@+id/btn_save"
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:background="@null"
        android:src="@drawable/ic_ok"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />
    <ImageButton
        android:id="@+id/btn_cancel"
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:layout_marginBottom="0dp"
        android:background="@null"
        android:src="@drawable/ic_cancel"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent" />
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="0dp"
        android:layout_marginEnd="8dp"
        android:orientation="horizontal"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/btn_save">
        <TextView
            android:id="@+id/textView4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="拖动选取"
            android:textColor="@color/white"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintTop_toTopOf="@+id/btn_save"
            app:layout_constraintVertical_bias="0.448"
            tools:layout_editor_absoluteX="61dp" />
        <TextView
            android:id="@+id/textView5"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="起始"
            android:textColor="#1aad19"
            tools:layout_editor_absoluteX="162dp"
            tools:layout_editor_absoluteY="476dp" />
        <TextView
            android:id="@+id/textView6"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="和"
            android:textColor="@color/white"
            tools:layout_editor_absoluteX="209dp"
            tools:layout_editor_absoluteY="475dp" />
        <TextView
            android:id="@+id/textView7"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="结束"
            android:textColor="#f45454"
            tools:layout_editor_absoluteX="243dp"
            tools:layout_editor_absoluteY="474dp" />
        <TextView
            android:id="@+id/textView8"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="区域"
            android:textColor="@color/white"
            tools:layout_editor_absoluteX="276dp"
            tools:layout_editor_absoluteY="474dp" />
    </LinearLayout>
</com.example.area_select_layout.AreaSelectLayout>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#008577</color>
    <color name="colorPrimaryDark">#00574B</color>
    <color name="colorAccent">#D81B60</color>
    <color name="red">#d02129</color>
    <color name="vip">#f5b53a</color>
    <color name="light_red">#ff620d</color>
    <color name="blue">#1189ff</color>
    <color name="blue_dark">#ff187998</color>
    <color name="white">#FFF</color>
    <color name="green">#ff1ce322</color>
    <color name="grey">#eeeffd</color>
    <color name="dark_gray">#525252</color>
    <color name="black">#000000</color>
    <color name="main">#09537a</color>
    <color name="main_trans">#991296db</color>
    <color name="full_trans">#00000000</color>
    <color name="no_trans">#00000001</color>
    <color name="half_trans">#80000000</color>
    <color name="status_bar">#09537a</color>
    <color name="df_layout">#fafafa</color>
    <color name="main_gray">#f5f5f5</color>
    <color name="waring">#ff620d</color>
    <color name="room_panel_bg">#80000000</color>
    <color name="sys_msg_bg">#b4b4b4</color>
    <color name="dialogue_msg">#3e3f3f</color>
    <color name="green0">#45C01A</color>
    <color name="green1">#45C01A</color>
    <color name="green2">#A3DEA3</color>
    <color name="green3">#1AAD19</color>
    <color name="ok">#1aad19</color>
    <color name="no">#ff620d</color>
    <color name="alpha_05_black">#0D000000</color>
    <color name="alpha_10_black">#1A000000</color>
    <color name="alpha_15_black">#26000000</color>
    <color name="alpha_20_black">#33000000</color>
    <color name="alpha_25_black">#40000000</color>
    <color name="alpha_30_black">#4D000000</color>
    <color name="alpha_33_black">#54000000</color>
    <color name="alpha_35_black">#59000000</color>
    <color name="alpha_40_black">#66000000</color>
    <color name="alpha_45_black">#73000000</color>
    <color name="alpha_50_black">#80000000</color>
    <color name="alpha_55_black">#8C000000</color>
    <color name="alpha_60_black">#99000000</color>
    <color name="alpha_65_black">#A6000000</color>
    <color name="alpha_70_black">#B3000000</color>
    <color name="alpha_75_black">#BF000000</color>
    <color name="alpha_80_black">#CC000000</color>
    <color name="alpha_85_black">#D9000000</color>
    <color name="alpha_90_black">#E6000000</color>
    <color name="alpha_95_black">#F2000000</color>
</resources>

「Android 自定义 View」—— AreaSelectL

实现思路

继承 View 还是 ViewGroup

跟随手指移动绘制方框

位置存储以及方向判断

使布局悬浮在应用之外

项目源码

manifests.xml

MainActivity.kt

AreaSelectLayout.kt

SystemSetings.kt

activity_main.xml

dialog_select_layout.xml

colors.xml

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