Java 微调器（如果再次选择项目）

我在包中创建了一个名为NoDefaultSpinner的类文件。但是，当我尝试在Android应用程序中使用它时，我遇到了一个异常，导致程序崩溃

我从中复制了Dimitar Vukman和Blundell提供的代码，然后在Alex Miragall指示下更新了这些代码（因为现在我正在为Android 4.0创建一个应用程序）。我删除了Dimitar的onClick方法，并将Alex的代码粘贴到类的末尾

然后我用微调器编辑我的活动，我改变了

static Spinner spinner1;

到

及

到

我也试着改变

<Spinner
        android:id="@+id/spinner1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/place" />

如果我更新布局（将微调器更改为NoDefaultSpinner），则这些是错误

我在stack上找到了两种解决问题的方法：

我的问题和问这些问题的人一样。这个问题在那里得到了很好的阐述

---

我尝试了所有的解决方案，但每次尝试启动带有这些特殊微调器的活动时，应用程序都会崩溃。也许我用错类了？

您的第一个异常是由

java.lang.ClassNotFoundException: Didn't find class "android.view.NoDefaultSpinner" on path: /data/app/com.example.life-1.apk

因此，在xml布局中使用完全限定名（

com.myPackage.NoDefaultSpinner

）。否则，Android假定该类是它自己包的一部分，它显然会失败

此外，这：

ClassCastException: android.widget.Spinner cannot be cast to com.example.life.NoDefaultSpinner

---

建议

NoDefaultSpinner

不扩展

Spinner

，请确保它是扩展的。

您可能需要执行

我从同一个包调用该类，不需要使用全名。我将在几分钟后编写日志是的，当您在XML中使用它的时候。正如@A--C所说，在XML中引用自定义视图时使用完全限定的包名。这是因为当您为Android应用程序编写XML时，解析器总是假定XML标记的默认名称空间位于
Android
中的某个位置。但是，在Java代码中，您是对的，对于同一个包中的东西，您不需要完全限定的名称
<Spinner
        android:id="@+id/spinner1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/place" />

<NoDefaultSpinner
        android:id="@+id/spinner1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/place" />

01-08 01:50:48.835: E/AndroidRuntime(13362): FATAL EXCEPTION: main
01-08 01:50:48.835: E/AndroidRuntime(13362): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.life/com.example.life.search_activity}: java.lang.ClassCastException: android.widget.Spinner cannot be cast to com.example.life.NoDefaultSpinner
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.os.Looper.loop(Looper.java:137)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.app.ActivityThread.main(ActivityThread.java:5039)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at java.lang.reflect.Method.invokeNative(Native Method)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at java.lang.reflect.Method.invoke(Method.java:511)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at dalvik.system.NativeStart.main(Native Method)
01-08 01:50:48.835: E/AndroidRuntime(13362): Caused by: java.lang.ClassCastException: android.widget.Spinner cannot be cast to com.example.life.NoDefaultSpinner
01-08 01:50:48.835: E/AndroidRuntime(13362):    at com.example.life.search_activity.onCreate(search_activity.java:181)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.app.Activity.performCreate(Activity.java:5104)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
01-08 01:50:48.835: E/AndroidRuntime(13362):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
01-08 01:50:48.835: E/AndroidRuntime(13362):    ... 11 more

01-08 01:53:22.803: E/AndroidRuntime(13417): FATAL EXCEPTION: main
01-08 01:53:22.803: E/AndroidRuntime(13417): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.life/com.example.life.search_activity}: android.view.InflateException: Binary XML file line #7: Error inflating class NoDefaultSpinner
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.os.Looper.loop(Looper.java:137)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.ActivityThread.main(ActivityThread.java:5039)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at java.lang.reflect.Method.invokeNative(Native Method)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at java.lang.reflect.Method.invoke(Method.java:511)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at dalvik.system.NativeStart.main(Native Method)
01-08 01:53:22.803: E/AndroidRuntime(13417): Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class NoDefaultSpinner
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:698)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.Activity.setContentView(Activity.java:1881)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at com.example.life.search_activity.onCreate(search_activity.java:177)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.Activity.performCreate(Activity.java:5104)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
01-08 01:53:22.803: E/AndroidRuntime(13417):    ... 11 more
01-08 01:53:22.803: E/AndroidRuntime(13417): Caused by: java.lang.ClassNotFoundException: Didn't find class "android.view.NoDefaultSpinner" on path: /data/app/com.example.life-1.apk
01-08 01:53:22.803: E/AndroidRuntime(13417):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.createView(LayoutInflater.java:552)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:643)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:660)
01-08 01:53:22.803: E/AndroidRuntime(13417):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:685)
01-08 01:53:22.803: E/AndroidRuntime(13417):    ... 21 more

java.lang.ClassNotFoundException: Didn't find class "android.view.NoDefaultSpinner" on path: /data/app/com.example.life-1.apk

ClassCastException: android.widget.Spinner cannot be cast to com.example.life.NoDefaultSpinner