当 android 中的数据绑定导致找不到符号 ActivityMainBindingImpl 时出错

Question

因此，我正在尝试使用本教程使用数据绑定在按钮上创建一个 onclick 侦听器。

数据绑定教程，因此当我将 onclick 保留在我的activity_main.xml布局中时，按钮单击有效。但是我想将我的数据发送到include_main_layout.xml但它告诉我我有错误。

build.gradle(app(

apply plugin: 'com.android.application'
android {
compileSdkVersion 29
dataBinding {
enabled = true
}

buildToolsVersion "29.0.2"
defaultConfig {
applicationId "com.example.datahelpsworld"
minSdkVersion 23
targetSdkVersion 29
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test.ext:junit:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}

主要活动.java

public class MainActivity extends AppCompatActivity {
User user;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);

user = new User();
user.setEmail("Ebola chebola chernobyl caronvirus");
user.setName("dilo dilo bolo bolo");

binding.setUser(user);

MyClickHandlers handlers = new MyClickHandlers(this);
binding.setHandlers(handlers);

}

public class MyClickHandlers {
Context context;
public MyClickHandlers(Context context) {
this.context = context;
}
public void onFabClicked(View view) {
user.setName("Ashutosh is awesome");
user.setEmail("email address is magical and cannot be retrieved");
Toast.makeText(getApplicationContext(), "FAB clicked!", Toast.LENGTH_SHORT).show();
}
public void onButtonClick() {
Toast.makeText(getApplicationContext(), "Button clicked!", Toast.LENGTH_SHORT).show();
}
public void onButtonClickWithParam(View view, User user) {
Toast.makeText(getApplicationContext(), "Button clicked! Name: " + user.getName(), Toast.LENGTH_SHORT).show();
}
public boolean onButtonLongPressed(View view) {
Toast.makeText(getApplicationContext(), "Button long pressed!", Toast.LENGTH_SHORT).show();
return false;
}
}
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:bind="http://schemas.android.com/apk/res-auto">
<data>

<variable
name="handlers"
type="com.example.datahelpsworld.MainActivity.MyClickHandlers" />
<variable
name="user"
type="com.example.datahelpsworld.User" />
</data>

<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="wrap_content"
android:orientation="vertical"
tools:context=".MainActivity">
<include
layout="@layout/main_layout"
bind:handlers="@{handlers}"
bind:user="@{user}" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:longClickable="true"
android:onClick="@{(v)->handlers.onFabClicked()}"
android:text="activity main layout">
</Button>
</LinearLayout>

</layout>

main_layout.xml

<layout>
<data>
<variable
name="user"
type="com.example.datahelpsworld.User" />

<variable
name="handlers"
type="com.example.datahelpsworld.MainActivity.MyClickHandlers" />

</data>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/username"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@{user.name}">
</TextView>
<TextView
android:id="@+id/email"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@{user.email}">
</TextView>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@={(v)->handlers.onButtonClick()}"
android:text="inside include">
</Button>

</LinearLayout>
</layout>

我的错误是以下几行。

error: cannot find symbol class ActivityMainBindingImpl

我尝试清理项目并从地面重建，但仍然没有运气。我做错了什么？

Answer 1

问题就在这里。

android:onClick="@{(v)->handlers.onFabClicked()}"

它应该android:onClick="@{handlers.onFabClicked()}"简单。

Answer 2

如果你想

从xml传递视图参数，那么你的onClick方法应该如下所示。

android:onClick="@{(v)->handlers.onFabClicked(v)}"