dependencies {
// Anko Commons
implementation "org.jetbrains.anko:anko-commons:$anko_version"
// Anko Layouts
implementation "org.jetbrains.anko:anko-sdk25:$anko_version" // sdk15, sdk19, sdk21, sdk23 are also available
implementation "org.jetbrains.anko:anko-appcompat-v7:$anko_version"
// Coroutine listeners for Anko Layouts
implementation "org.jetbrains.anko:anko-sdk25-coroutines:$anko_version"
implementation "org.jetbrains.anko:anko-appcompat-v7-coroutines:$anko_version"
// Anko SQLite
implementation "org.jetbrains.anko:anko-sqlite:$anko_version"
}
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val listItems = arrayOf("Russia", "USA", "Japan", "Australia") //传数组
val listDialog: AlertDialog.Builder = AlertDialog.Builder(this)
listDialog.setItems(listItems) { p0, p1 ->
toast(p1)
}
val dialog: AlertDialog = listDialog.create()
dialog.show()
val window: Window = dialog.window
val params: WindowManager.LayoutParams = window.attributes
params.y = 45 * ScreenUtils.getScreenDensity().toInt()
params.gravity = Gravity.TOP or Gravity.RIGHT
params.width = ScreenUtils.getScreenWidth() / 2
params.height = ViewGroup.LayoutParams.WRAP_CONTENT
window.attributes = params
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但是我们用Anko是这样的：
val countries = listOf("Russia", "USA", "Japan", "Australia") //传list
selector("Where are you from?", countries, { dialogInterface, i ->
toast("So you're living in ${countries[i]}, right?")
})
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看起来只是简化了dialog的创建过程。
2.2.5 Progress dialogs
不显示进度的 Loading Dialg
pressDialog("Please wait a minute.", "Downloading…")
indeterminateProgressDialog("Fetching the data…")
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2.3 Logging
打印log辅助工具。
Android SDK 提供 android.util.Log 类来提供一些 logging 方法，，这些方法都很实用，但是我们每次必须传递一个 Tag 参数，同时这个 Tag 信息必须是 String 类型的，这就略显麻烦。不过现在我们可以通过 AnkoLogger 类摆脱这些恼人的问题：
class SomeActivity : Activity(), AnkoLogger {
fun someMethod() {
info("Info message")
debug(42) // .toString() method will be called automatically
}
}
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默认的 Tag 名是当前的类名( 本例中的是SomeActivity），但是通过重写 AnkoLogger 的 loggerTag 属性我们是可以来更改的，而且每个方法有两个版本： plain and lazy (inlined)
class SomeActivity : Activity() {
private val log = AnkoLogger(this.javaClass)
private val logWithASpecificTag = AnkoLogger("my_tag")
private fun someMethod() {
log.warning("Big brother is watching you!")
}
}
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上面两种方法分别是不同Tag的实现方式。
AnkoLogger中loggerTag 属性具体对照如下：
2.4 Resources and dimensions
你可以在你的项目中使用Anko Resources and dimensions来简化你的代码，例如Color、Dimen等，颜色透明度直接色值.opaque就可以，尺寸的话直接使用dip(dipValue)、sp(spValue)就可以。在这里面还有一个就是applyRecursively()用来控制子View的操作，如：
class DatabaseHelper(ctx: Context) : ManagedSQLiteOpenHelper(ctx, "LibraryDatabase", null, 1) {
companion object {
private var instance: DatabaseHelper? = null
@Synchronized
fun Instance(context: Context): DatabaseHelper {
if (instance == null) {
instance = DatabaseHelper(context.applicationContext)
}
return instance!!
}
}
override fun onCreate(database: SQLiteDatabase) {
createTable(Book.TABLE_NAME, true, Book.COLUMN_ID to INTEGER + PRIMARY_KEY, Book.COLUMN_TITLE to TEXT, Book.COLUMN_AUTHOR to TEXT)
}
override fun onUpgrade(database: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
dropTable(Book.TABLE_NAME, true)
}
}
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访问数据库的推荐做法是通过依赖注入，或者为 Context 添加一个 extension:
val Context.database: DatabaseHelper
get() = DatabaseHelper.Instance(applicationContext)
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下面这是一个简单的 model 类：
data class Book(val id: Int, val title: String, val author: String) {
companion object {
val Book.COLUMN_ID = "id"
val TABLE_NAME = "books"
val COLUMN_TITLE = "title"
val COLUMN_AUTHOR = "author"
}
}
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当数据库准备好后，就可以通过 use 方法来进行操作了。比如：
database.use {
insert(Book.TABLE_NAME, Book.COLUMN_ID to 1, Book.COLUMN_TITLE to "2666", Book.COLUMN_AUTHOR to "Roberto Bolano")
}
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doAsync(UI) {
val data: Deferred<Data> = bg {
// Runs in background
getData()
}
// This code is executed on the UI thread
showData(data.await())
}
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David Sawyer McFarland / O Reilly / 2011-10-28 / USD 39.99
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