我正在尝试使用include标签添加一些自定义视图到我使用DataBinding的活动布局。我的自定义视图也使用DataBinding。但是我在申请开始时遇到了崩溃：
05-02 17:30:03.685 12595-12595/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.novachevskyi.databindingtest, PID: 12595
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.novachevskyi.databindingtest/com.novachevskyi.databindingtest.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.novachevskyi.databindingtest.databinding.CustomViewBinding.invalidateAll()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.novachevskyi.databindingtest.databinding.CustomViewBinding.invalidateAll()' on a null object reference
at com.novachevskyi.databindingtest.databinding.ActivityMainBinding.invalidateAll(ActivityMainBinding.java:41)
at com.novachevskyi.databindingtest.databinding.ActivityMainBinding.<init>(ActivityMainBinding.java:33)
at com.novachevskyi.databindingtest.databinding.ActivityMainBinding.bind(ActivityMainBinding.java:105)
at android.databinding.DataBinderMapper.getDataBinder(DataBinderMapper.java:11)
at android.databinding.DataBindingUtil.bind(DataBindingUtil.java:185)
at android.databinding.DataBindingUtil.bindToAddedViews(DataBindingUtil.java:299)
at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:279)
at android.databinding.DataBindingUtil.setContentView(DataBindingUtil.java:261)
at com.novachevskyi.databindingtest.MainActivity.onCreate(MainActivity.java:11)
at android.app.Activity.performCreate(Activity.java:6251)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
我的名字是c：
public class MainActivity extends AppCompatActivity {
@Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
DataBindingUtil.setContentView(this, R.layout.activity_main);
}
}
CustomView：
public class CustomView extends LinearLayout {
public CustomView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override protected void onFinishInflate() {
super.onFinishInflate();
DataBindingUtil.bind(this);
}
}
activity_main.xml中：
<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.novachevskyi.databindingtest.MainActivity">
<include layout="@layout/custom_view"/>
</RelativeLayout>
</layout>
custom_view.xml：
<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android">
<com.novachevskyi.databindingtest.CustomView
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:text="Hello World!"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</com.novachevskyi.databindingtest.CustomView>
</layout>
我还创建了带有示例项目的公共回购：https://github.com/novachevskyi/DataBinding-issue
我正在使用com.android.tools.build:gradle:1.3.1的数据绑定，现在，当我尝试将构建工具版本升级到com.android.tools.build:gradle:2.1.0时，我面临着包含include xml标记的所有视图的问题。对于上述问题的任何信息，我们将不胜感激。
我看了看你的项目并运行它。我认为它崩溃的原因是因为
@Override protected void onFinishInflate() {
super.onFinishInflate();
DataBindingUtil.bind(this);
}
如果你删除DataBindingUtil.bind(this)它将停止崩溃。原因是绑定调用正在寻找围绕视图的qazxswpo，但它找不到它所以它抛出异常。由于CustomView在自身上调用bind，因此它不被任何导致<layout>到ViewDataBinding的东西所包围
我并不完全确定你想要实现的目标，但是在throw new IllegalArgumentException("View is not a binding layout")中调用bind将是多余的，因为当它绑定活动的布局时，活动正在为你做这件事。如果您需要onFinishInflate类中的绑定，您可以执行以下操作：
CustomView@ SeptimusX75的答案不起作用，因为@Override protected void onAttachedToWindow() {
super.onAttachedToWindow();
CustomViewBinding binding = DataBindingUtil.findBinding(this);
}
在内部调用DataBindingUtil.findBinding(this)来获取绑定，但是当调用this.getTag(R.id.dataBinding)时标签尚未设置。
相反，当您需要使用绑定时，尝试通过onFinishInflate获取绑定。
this.getTag(R.id.dataBinding);或者，在调用CustomView上的任何方法之前，从活动中手动设置绑定。
public class CustomView extends LinearLayout {
// ...
public CustomViewBinding binding;
// ...
public void setTitle(final String text) {
if (binding == null) {
binding = Objects.requireNonNull(getTag(R.id.dataBinding));
}
binding.title.setText(text);
}
}
public class CustomView extends LinearLayout {
// ...
public CustomViewBinding binding;
// ...
public void setBinding(final CustomViewBinding binding) {
this.binding = binding;
}
}
如果有其他人犯了er..dumb错误我做了......
当我错误地使用两个重复的布局文件时，发生了这个错误，一个使用数据绑定，另一个没有...
删除副本为我修复了错误。