具有包含布局的数据绑定变量继承 [英] Databinding variable inheritance with included layout
问题描述
我正在学习数据绑定和mvvm.我有一个问题,我希望BaseViewModel.kt
包括一些与UI相关的变量,例如isLoading
标志和loadingText
.发出网络请求时,我将isLoading
设置为true,并且基本视图模型的某个子级应该设置文本.例如,对于LoginViewModel.kt
,文本可能是正在登录".是否可以将这些变量传递到包含的基本布局中?
I am learning data binding and mvvm. I have an issue where I would like a BaseViewModel.kt
to include some UI related variables such as an isLoading
flag and loadingText
. When a network request is made, I set isLoading
to true and some child of my base view model should set the text. For example for a LoginViewModel.kt
the text might be 'logging in'. Is it possible to pass these variables to an included base layout?
因此login_activity.xml
可能在其布局中包含此内容:
So a login_activity.xml
might include this in it's layout:
<data>
<import type="android.view.View" />
<variable
name="viewModel"
type="core.sdk.ui.login.LoginViewModel" />
</data>
<!-- Various click listeners using the viewModel variable -->
<include
android:id="@+id/progress_include"
layout="@layout/progress_bar"
android:visibility="@{viewModel.isLoading ? View.VISIBLE : View.GONE}"
bind:viewModel="@{viewModel}"/>
现在,我希望我的progress_bar.xml
美观且通用,并使用基本视图模型:
Now I want my progress_bar.xml
to be nice and generic and use the base view model:
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:context="core.sdk.ui.login.LoginActivity">
<data>
<import type="android.view.View" />
<variable
name="viewModel"
type="core.sdk.ui.base.BaseViewModel" />
</data>
<LinearLayout
android:id="@+id/circular_progress"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:gravity="center"
android:orientation="vertical">
<android.support.v4.widget.ContentLoadingProgressBar
style="@style/Widget.AppCompat.ProgressBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/progress_text"
style="@style/TextAppearance.AppCompat.Subhead"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fontFamily="sans-serif-thin"
android:gravity="center_horizontal"
android:text="@{viewModel.loadingText}"
android:textStyle="italic"
tools:text="loading..." />
</LinearLayout>
我得到的错误是类似的
****/ data binding error ****msg:Cannot find the setter for attribute 'bind:viewModel' with parameter type core.sdk.ui.login.LoginViewModel
如果这不可能,我只能看到的唯一方法是删除包含的内容,并将进度条和文本复制并粘贴到每个视图模型中,这不是很好.
If this isn't possible the only alternative I can see is to remove the include and copy and paste the progress bar + text to every view model which isn't very nice.
推荐答案
我认为您应该将其投射在绑定中:
I think you should cast it in the binding:
<include
android:id="@+id/progress_include"
layout="@layout/progress_bar"
android:visibility="@{viewModel.isLoading ? View.VISIBLE : View.GONE}"
bind:viewModel="@{(core.sdk.ui.base.BaseViewModel)viewModel}"/>
这篇关于具有包含布局的数据绑定变量继承的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!