Anko 0.8-未解析的lparams参考 [英] Anko 0.8 - unresolved lparams reference

问题描述

主要问题是:lparams只是从Anko消失了，还是我做错了什么?以下代码段无法编译:

The main question is: is lparams simply gone from Anko, or am I doing something terribly wrong? The following snippet fails to compile:

verticalLayout {
}.lparams(width = matchParent, height = matchParent) {
    topMargin = dip(10)
}

虽然可以正常工作，但没有任何问题:

While this works without any problems:

verticalLayout {
    layoutParams = LinearLayout.LayoutParams(matchParent, matchParent).apply {
        topMargin = dip(10)
    }
}

我不太在乎第二个选项，但是在生成参数时必须指定布局类型，这可能会有点累(并且比原始解决方案还脆弱).

I wouldn't mind the second option too much, but you have to specify the layout type when generating the params, which can get a bit tiresome (and is also more brittle than the original solution).

在Anko GitHub页面上，更改日志中，或者通过浏览最近的提交，我都没有找到任何东西.这是完整的UI类供参考:

I haven't found anything on the Anko GitHub page, the changelog, or by skimming recent commits. Here's the full UI class for reference:

class ReviewsFragmentUi(ctx: AnkoContext<ReviewsFragment>) : AnkoComponent<ReviewsFragment> {
    override fun createView(ui: AnkoContext<ReviewsFragment>) = ui.apply {
        verticalLayout {
            layoutParams = LinearLayout.LayoutParams(matchParent, matchParent).apply {
                topMargin = dip(10)
            }
        }
    }.view
}

相关的Gradle条目(我使用的是Kotlin 1.0.0-beta-3595):

Relevant Gradle entries (I'm using Kotlin 1.0.0-beta-3595):

ext.versions = [
    anko : '0.8.1',
]

compile "org.jetbrains.anko:anko-common:$versions.anko",
compile "org.jetbrains.anko:anko-sdk21:$versions.anko",
compile "org.jetbrains.anko:anko-support-v4:$versions.anko",
compile "org.jetbrains.anko:anko-design:$versions.anko",
compile "org.jetbrains.anko:anko-appcompat-v7:$versions.anko",
compile "org.jetbrains.anko:anko-cardview-v7:$versions.anko",
compile "org.jetbrains.anko:anko-recyclerview-v7:$versions.anko",
compile "org.jetbrains.anko:anko-gridlayout-v7:$versions.anko",

作为后续问题:如果lparams确实消失了，那么有没有比我已经在做的更好的替代品了?

As a follow-up question: if lparams is indeed gone, then is there a more elegant replacement than what I'm already doing?

推荐答案

显然lparams仍然存在，但不能用作最外层布局的扩展功能:

Apparently lparams is still there, but cannot be used as an extension function for the outermost layout:

因此以下代码失败:

override fun createView(ui: AnkoContext<ReviewsFragment>) = ui.apply {
    verticalLayout {
        // Layout elements here
    }.lparams { 
        // Layout params here
    }
}.view

但这可以很好地编译:

override fun createView(ui: AnkoContext<ReviewsFragment>) = ui.apply {
    verticalLayout {
        lparams {
            // Layout params here
        }

        // Layout elements here
        verticalLayout { }.lparams {
            // lparams works fine if there is a parent layout
        }
    } 
}.view

值得注意的是，内部布局不建议使用lparams的非tailing版本:当嵌套布局的类型不同时，它将创建LayoutParams的错误子集.有关完整的讨论，请参见此 GitHub问题.

It's worth noting that using the non-tailing version of lparams is discouraged for inner layouts: it will create the wrong sublass of LayoutParams when the nested layouts are of different types. For a complete discussion, see this GitHub Issue.

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