如何在嵌套布局中设置 Android DataBinding
How to set Android DataBinding in nested layouts
我刚刚阅读了 android 中的数据绑定功能。我试图从嵌套布局绑定视图。我的 activity 是 android 的默认模板 DrawerMenuActivity，它有 content_my_activity 布局嵌套在 activity_my_activity 布局中。
我有 3 个自动生成的绑定 classes。 MyActivityBinding、AppBarMyActivityBinding 和 ContentMyActivityBinding。
我尝试初始化所有 3 个 class，如下所示：
MyActivity.java
MyActivityBinding activityBinding;
AppBarMyActivityBinding appBarBinding;
ContentMyActivityBinding contentBinding;
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
activityBinding = DataBindingUtils.setContentView(this,
R.layout.activity_my_activity);
appBarBinding = DataBindingUtils.setContentView(this,
R.layout.app_bar_my_activity);
contentBinding = DataBindingUtils.setContentView(this,
R.layout.content_my_activity);
setName();
}
private void setName(){
contentBinding.setFirstName("Omkar");
}
但它抛出如下 RuntimeException：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example, PID: 18305
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example/com.example.userInterface.activity.MyActivity}: android.view.InflateException: Binary XML file line #35: Binary XML file line #27: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2426)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.access0(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Caused by: android.view.InflateException: Binary XML file line #35: Binary XML file line #27: Error inflating class fragment
at android.view.LayoutInflater.inflate(LayoutInflater.java:539)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276)
at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88)
at android.app.Activity.performCreate(Activity.java:6259)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.access0(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Caused by: android.view.InflateException: Binary XML file line #27: Error inflating class fragment
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:782)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:838)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:971)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:831)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276)
at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88)
at android.app.Activity.performCreate(Activity.java:6259)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.access0(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Caused by: java.lang.IllegalArgumentException: Binary XML file line #27: Duplicate id 0x7f0e0081, tag null, or parent id 0xffffffff with another fragment for com.google.android.gms.maps.SupportMapFragment
at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2416)
at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:120)
at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:374)
at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:33)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:75)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:754)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:838)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:971)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:831)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276)
at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88)
at android.app.Activity.performCreate(Activity.java:6259)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.access0(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
如何在 MyActivity.java class 中绑定来自 content_my_activity 的视图，如有任何帮助，我们将不胜感激。
谢谢。
DataBindingUtils.setContentView() 完全按照它的名字命名：它将当前视图设置为给定的参数。我认为您不希望 AppBar 作为整个视图，是吗？
尽管如此，我假设您 include 您的布局在 layout_activity_main.xml 中。 George Mount 写了一篇关于此功能的 whole blog post。代码示例来自此 post。
第一个示例是您的 layout_activity_main.xml（或者无论您如何命名），其中包括您的 AppBar、您的 Content 等等。
hello_world.xml
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/hello"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<include
android:id="@+id/world1"
layout="@layout/included_layout"/>
<include
android:id="@+id/world2"
layout="@layout/included_layout"/>
</LinearLayout>
</layout>
included_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/world"/>
</layout>
现在使用的布局已经很清楚了，您需要跳转到 ActivityMain，初始化 DataBinding 并访问您的字段：
//This works if you have used a variable in your <data> tag and you have built your project afterwards, if you don't have an activity
HelloWorldBinding binding = HelloWorldBinding.inflate(getLayoutInflater());
//if you have an activity, you can use setContentView from the DataBindingUtils. Don't forget to delete the generic setContentView
HelloWorldBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_my_activity);
//Once you have accomplished the above, you can access your data-bound fields like this:
binding.hello.setText(“Hello”);
binding.world1.world.setText(“First World”);
binding.world2.world.setText(“Second World”);
重要的是将 Ids 设置为您的 <include> 标签以便在您的 Activity.
中正确访问它们
可以传递 XML 中的对象...需要 xmlns:bind 命名空间（类似于 xmlns:app）。
<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:bind="http://schemas.android.com/apk/res-auto">
<data>
<variable name="user" type="com.example.User"/>
</data>
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<include
layout="@layout/name"
bind:user="@{user}"/>
<include
layout="@layout/contact"
bind:user="@{user}"/>
</LinearLayout>
</layout>
我刚刚阅读了 android 中的数据绑定功能。我试图从嵌套布局绑定视图。我的 activity 是 android 的默认模板 DrawerMenuActivity，它有 content_my_activity 布局嵌套在 activity_my_activity 布局中。
我有 3 个自动生成的绑定 classes。 MyActivityBinding、AppBarMyActivityBinding 和 ContentMyActivityBinding。
我尝试初始化所有 3 个 class，如下所示：
MyActivity.java
MyActivityBinding activityBinding;
AppBarMyActivityBinding appBarBinding;
ContentMyActivityBinding contentBinding;
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
activityBinding = DataBindingUtils.setContentView(this,
R.layout.activity_my_activity);
appBarBinding = DataBindingUtils.setContentView(this,
R.layout.app_bar_my_activity);
contentBinding = DataBindingUtils.setContentView(this,
R.layout.content_my_activity);
setName();
}
private void setName(){
contentBinding.setFirstName("Omkar");
}
但它抛出如下 RuntimeException：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example, PID: 18305
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example/com.example.userInterface.activity.MyActivity}: android.view.InflateException: Binary XML file line #35: Binary XML file line #27: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2426)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.access0(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Caused by: android.view.InflateException: Binary XML file line #35: Binary XML file line #27: Error inflating class fragment
at android.view.LayoutInflater.inflate(LayoutInflater.java:539)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276)
at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88)
at android.app.Activity.performCreate(Activity.java:6259)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.access0(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Caused by: android.view.InflateException: Binary XML file line #27: Error inflating class fragment
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:782)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:838)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:971)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:831)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276)
at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88)
at android.app.Activity.performCreate(Activity.java:6259)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.access0(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Caused by: java.lang.IllegalArgumentException: Binary XML file line #27: Duplicate id 0x7f0e0081, tag null, or parent id 0xffffffff with another fragment for com.google.android.gms.maps.SupportMapFragment
at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2416)
at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:120)
at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:374)
at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:33)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:75)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:754)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:838)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:971)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:831)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:276)
at com.example.userInterface.activity.MyActivity.onCreate(MyActivity.java:88)
at android.app.Activity.performCreate(Activity.java:6259)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.access0(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
如何在 MyActivity.java class 中绑定来自 content_my_activity 的视图，如有任何帮助，我们将不胜感激。
谢谢。
DataBindingUtils.setContentView() 完全按照它的名字命名：它将当前视图设置为给定的参数。我认为您不希望 AppBar 作为整个视图，是吗？
尽管如此，我假设您 include 您的布局在 layout_activity_main.xml 中。 George Mount 写了一篇关于此功能的 whole blog post。代码示例来自此 post。
第一个示例是您的 layout_activity_main.xml（或者无论您如何命名），其中包括您的 AppBar、您的 Content 等等。
hello_world.xml
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/hello"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<include
android:id="@+id/world1"
layout="@layout/included_layout"/>
<include
android:id="@+id/world2"
layout="@layout/included_layout"/>
</LinearLayout>
</layout>
included_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/world"/>
</layout>
现在使用的布局已经很清楚了，您需要跳转到 ActivityMain，初始化 DataBinding 并访问您的字段：
//This works if you have used a variable in your <data> tag and you have built your project afterwards, if you don't have an activity
HelloWorldBinding binding = HelloWorldBinding.inflate(getLayoutInflater());
//if you have an activity, you can use setContentView from the DataBindingUtils. Don't forget to delete the generic setContentView
HelloWorldBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_my_activity);
//Once you have accomplished the above, you can access your data-bound fields like this:
binding.hello.setText(“Hello”);
binding.world1.world.setText(“First World”);
binding.world2.world.setText(“Second World”);
重要的是将 Ids 设置为您的 <include> 标签以便在您的 Activity.
可以传递 XML 中的对象...需要 xmlns:bind 命名空间（类似于 xmlns:app）。
<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:bind="http://schemas.android.com/apk/res-auto">
<data>
<variable name="user" type="com.example.User"/>
</data>
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<include
layout="@layout/name"
bind:user="@{user}"/>
<include
layout="@layout/contact"
bind:user="@{user}"/>
</LinearLayout>
</layout>