Programmatically inflated layout with Kotlin Andro

2019-06-15 21:20发布

问题:

I have a following layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@android:color/white"
    android:paddingLeft="20dp"
    android:paddingRight="20dp">

    <TextView
        android:id="@+id/tvErrorTitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:textColor="@android:color/background_dark"
        android:textSize="18sp"
        />
    <TextView
        android:id="@+id/tvErrorDesc"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:textColor="@android:color/darker_gray"
        android:textSize="16sp"
        />
    <TextView
        android:id="@+id/tvAction"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:layout_marginBottom="10dp"
        android:layout_gravity="end"
        android:padding="5dp"
        android:textSize="15sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:textColor="@android:color/holo_purple"
        />
</LinearLayout>

When I want to use kotlin android extensions outside of activity like below, it doesn't work. I ended up doing findViewById.

...
...
import kotlinx.android.synthetic.main.dialog_error.*
...
...
 val view = LayoutInflater.from(context).inflate(R.layout.dialog_error, null, false)
    val tvErrorTitle = view.findViewById(R.id.tvErrorTitle) as TextView
    val tvErrorDesc = view.findViewById(R.id.tvErrorDesc) as TextView
    val tvErrorAction = view.findViewById(R.id.tvAction) as TextView

It doesn't pull the views directly from xml. How to use it in programetically inflated layout and avoid findViewById?

Note : This question strictly belongs to Kotlin Android Extensions, not the language itself.

Edit I have imported both :

import kotlinx.android.synthetic.main.dialog_error.view.*
import kotlinx.android.synthetic.main.dialog_error.*

But Android Studio still tries to import from R.id and doesn't recognize those two imports. Is there anything missing?

回答1:

From the docs you linked:

If we want to call the synthetic properties on View (useful in adapter classes), we should also import

kotlinx.android.synthetic.main.activity_main.view.*.

That is, import kotlinx.android.synthetic.main.layout.view.* as well to load the View extension properties.

Then:

val view = LayoutInflater.from(context).inflate(...)
view.tvErrorTitle.text = "test"


回答2:

It returns a view inflated:

layoutInflater.inflate(R.layout.your_layout, null)

See, you can replace this LayoutInflater.from(context) with this layoutInflater when your class extend from a Context superclass