Intent数据传输：超简洁

用Intent传输数据是安卓常用技术之一，通常的方法是声名一堆键名(key_name)，把数据存储到Intent中，然后在其它地方根据键名和类别读取。

示例如下：

val KEY_USER_NAME = "key_user_name"
val KEY_USER_PWD = "key_user_pwd"
val KEY_USER_NEW = "key_user_new"

val intent = Intent()
intent.putExtra(KEY_USER_NAME, "name")
intent.putExtra(KEY_USER_PWD, 123)
intent.putExtra(KEY_USER_NEW, true)

val name = intent.getStringExtra(KEY_USER_NAME)
val pwd = intent.getIntExtra(KEY_USER_PWD, -1)
val newUser = intent.getBooleanExtra(KEY_USER_NEW, false)

虽然取键名很简单，但如果取太多的话，就不知道取什么好了，到最后可能干脆直接用‘KEY_1’什么的。取无意义键名，容易出现用错名或类型错误的问题，怎么破？用XIntent传输数据，超简洁！

启动Activity

//直接启动新页面，可以把数据跟在后面
XIntent.startActivity(this, MainActivity::class, name, pwd, newUser)

//startActivityForResult方式启动
val intent = XIntent(this, MainActivity::class, name, pwd, newUser)
startActivityForResult(intent, 1)

//读取上个页面传过来的数据
XIntent.with(this).apply {
    val name: String = readExtra()!!
    val pwd: Int = readExtra()!!
    val newUser: Boolean = readExtra()!!
}

SaveInstanceState

override fun onSaveInstanceState(outState: Bundle, outPersistentState: PersistableBundle?) {
    super.onSaveInstanceState(outState, outPersistentState)
    val saveTime = System.currentTimeMillis()
    val user = "userName"
    val pwd = 123
    val newUser = true
    XIntent.with(outState).putSerializableExtra(saveTime, user, pwd, newUser)
}

override fun onRestoreInstanceState(savedInstanceState: Bundle, persistentState: PersistableBundle?) {
    super.onRestoreInstanceState(savedInstanceState, persistentState)
    XIntent.with(savedInstanceState).apply {
        val saveTime: Long? = readExtra()
        val user: String? = readExtra()
        val pwd: Int? = readExtra()
        val newUser: Boolean? = readExtra()
    }
}

ActivityResult

//setResult
XIntent.with().apply {
    val backTime = System.currentTimeMillis()
    putSerializableExtra(backTime)
    setResult(RESULT_OK, this)
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    val backTime: Long? = XIntent.with(data).readExtra()
}

方法说明

//支持三种类型参数
XIntent.with(Activity | Intent? | Bundle): IntentWrapper

IntentWrapper{
    //请确保传入参数都能强制转换为serializable，支持 List，不支持 List
    fun putSerializableExtra(vararg serializable: Any?)
    fun getSerializableExtra(): Array?
    //根据数据类型读取，注：不支持 List 类型（能读到数据，但List的泛型无法读到）
    inline fun  readExtra(defaultValue: T? = null): T?
    //根据 Index 读取类型重复的数据
    inline fun  readExtra(index: Int, defaultValue: T? = null): T?
    inline fun  readExtraList(): List
}

Gradle dependency

最新版本-jitpack

XIntent-github

allprojects {
    repositories {
        mavenLocal()
        maven { url 'https://jitpack.io' }//add to project build.gradle
    }
}

compile 'com.github.DonaldDu:XIntent:x.x.x'//add to module build.gradle

最后

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