必需的 DataBindingComponent 在类 AgentDetailsActivityBindingImpl 中为 null

Question

在我的 agent_details_activity.xml 中：

 <ImageView
            android:id="@+id/imageViewPhoto"
            android:layout_width="0dp"
            android:layout_height="400dp"
            app:agentImageUrl="@{item.url}"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/toolBarContainer" />

在活动中：

class AgentDetailsActivity : AppCompatActivity() {
    private lateinit var binding: AgentDetailsActivityBinding

    companion object {
        val AGENT_DETAILS = AgentDetailsActivity::class.java.name + "_AGENT_DETAILS"
    }

    private val TAG = AgentDetailsActivity::class.java.name

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = AgentDetailsActivityBinding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.setHandler(this);
    }

  @BindingAdapter("agentImageUrl")
    fun loadImage(view: ImageView, imageUrl: String) {
        Glide.with(view.context)
            .load(imageUrl)
            .apply(RequestOptions().error(R.drawable.no_image))
            .into(view)
    }

但在运行时我得到错误：

Shutting down VM
 FATAL EXCEPTION: main
 Process: com.android.testproject.android.kotlin.debug, PID: 24924
 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.testproject.android.kotlin.debug/com.android.testproject.android.kotlin.coroutine_retrofit.ui.activity.AgentDetailsActivity}: java.lang.IllegalStateException: Required DataBindingComponent is null in class AgentDetailsActivityBindingImpl. A BindingAdapter in com.android.testproject.android.kotlin.coroutine_retrofit.ui.activity.AgentDetailsActivity is not static and requires an object to use, retrieved from the DataBindingComponent. If you don't use an inflation method taking a DataBindingComponent, use DataBindingUtil.setDefaultComponent or make all BindingAdapter methods static.
    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.IllegalStateException: Required DataBindingComponent is null in class AgentDetailsActivityBindingImpl. A BindingAdapter in com.android.testproject.android.kotlin.coroutine_retrofit.ui.activity.AgentDetailsActivity is not static and requires an object to use, retrieved from the DataBindingComponent. If you don't use an inflation method taking a DataBindingComponent, use DataBindingUtil.setDefaultComponent or make all BindingAdapter methods static.
    at androidx.databinding.ViewDataBinding.ensureBindingComponentIsNotNull(ViewDataBinding.java:666)
    at com.android.testproject.android.kotlin.databinding.AgentDetailsActivityBindingImpl.<init>(AgentDetailsActivityBindingImpl.java:40)
    at com.android.testproject.android.kotlin.databinding.AgentDetailsActivityBindingImpl.<init>(AgentDetailsActivityBindingImpl.java:32)
    at com.android.testproject.android.kotlin.DataBinderMapperImpl.getDataBinder(DataBinderMapperImpl.java:52)
    at androidx.databinding.MergedDataBinderMapper.getDataBinder(MergedDataBinderMapper.java:74)
    at androidx.databinding.DataBindingUtil.bind(DataBindingUtil.java:199)
    at androidx.databinding.DataBindingUtil.inflate(DataBindingUtil.java:130)
    at androidx.databinding.ViewDataBinding.inflateInternal(ViewDataBinding.java:1366)
    at com.android.testproject.android.kotlin.databinding.AgentDetailsActivityBinding.inflate(AgentDetailsActivityBinding.java:95)
    at com.android.testproject.android.kotlin.databinding.AgentDetailsActivityBinding.inflate(AgentDetailsActivityBinding.java:81)
    at com.android.testproject.android.kotlin.coroutine_retrofit.ui.activity.AgentDetailsActivity.onCreate(AgentDetailsActivity.kt:37)
    at android.app.Activity.performCreate(Activity.java:6251)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)

Answer 1

详细说明@mahdi shahbazi 的答案（绑定适配器方法必须是静态的）：

在 kotlin 中，将你的绑定方法放在任何类之外（所以在你的情况下 Activity 类之外）。这将解决问题。在你的情况下，它看起来像：

@BindingAdapter("agentImageUrl")
fun loadImage(view: ImageView, imageUrl: String) {
    Glide.with(view.context)
        .load(imageUrl)
        .apply(RequestOptions().error(R.drawable.no_image))
        .into(view)
}

class AgentDetailsActivity : AppCompatActivity() {
    private lateinit var binding: AgentDetailsActivityBinding

    companion object {
        val AGENT_DETAILS = AgentDetailsActivity::class.java.name + "_AGENT_DETAILS"
    }

    private val TAG = AgentDetailsActivity::class.java.name

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = AgentDetailsActivityBinding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.setHandler(this);
    }

    ...

}

由于这篇文章，我已经能够想出这个答案：https : //proandroiddev.com/custom-attributes-using-bindingadapters-in-kotlin-971ef8fcc259。其中还有很多其他好的技巧，我建议您查看它以获取有关视图绑定的美味佳肴。

Answer 2

就我而言，我找到了一个非常简单的方法，我和你有同样的错误。我只需要添加@JvmStatic注释。

代码如下所示：

 @JvmStatic // add this line !!
 @BindingAdapter("agentImageUrl")
    fun loadImage(view: ImageView, imageUrl: String) {
        Glide.with(view.context)
            .load(imageUrl)
            .apply(RequestOptions().error(R.drawable.no_image))
            .into(view)
    }

Answer 3

是的，首先将您的绑定方法放在任何类之外。其次，使 imageUrl 可以为空！因为如果您将 imageUrl 设为 null，您将调用崩溃而不是 onError

@BindingAdapter("agentImageUrl")
fun loadImage(view: ImageView, imageUrl: String?) {
    Glide.with(view.context)
        .load(imageUrl)
        .apply(RequestOptions().error(R.drawable.no_image))
        .into(view)
}

Answer 4

    // Solution 1
@BindingAdapter("android:loadImage")
fun loadImage(userImageView: ImageView, imageUrl: String): Unit {
    Glide
        .with(userImageView)
        .load(imageUrl)
        .into(userImageView)
}

**This is my solution, I have written my function outside the class**