我有一个自定义视图,使用这些构造函数扩展LinearLayout:
public class CustomView extends LinearLayout {
public CustomView(Context context) {
this(context, null);
}
public CustomView(Context context, AttributeSet attrs) {
this(context, attrs, R.attr.customViewStyle);
}
public CustomView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
/* set custom attributes with TypedArray */
}
/* other methods */
}
在我的/res/values/attrs.xml中:
<attr name="customViewStyle" format="reference" />
<declare-styleable name="CustomeView">
<attr name="value" format="integer" />
<attr name="android:imeOptions" />
<attr name="android:imeActionId" />
<attr name="android:imeActionLabel" />
</declare-styleable>
在我的/res/values/styles.xml中:
<style name="AppTheme" parent="@android:style/Theme.Black">
<item name="android:windowBackground">@drawable/bg_dark_fiber</item>
<item name="customViewStyle">@style/CustomViewStyle</item>
</style>
<style name="CustomViewStyle">
<item name="android:clickable">true</item>
<item name="android:focusable">true</item>
<item name="android:focusableInTouchMode">true</item>
</style>
AppTheme被设置为整个应用程序的主题。理想的结果是我的自定义视图是可聚焦的并且可以在默认情况下单击,而不必在布局文件中添加这些属性(而不是常规的LinearLayout)。当我运行应用程序时,它会崩溃并显示以下堆栈跟踪:
05-17 14:58:53.010: E/ActivityThread(26767): Failed to inflate
05-17 14:58:53.010: E/ActivityThread(26767): android.view.InflateException: Binary XML file line #8: Error inflating class com.example.customviews.CustomView
05-17 14:58:53.010: E/ActivityThread(26767): at android.view.LayoutInflater.createView(LayoutInflater.java:518)
05-17 14:58:53.010: E/ActivityThread(26767): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:570)
05-17 14:58:53.010: E/ActivityThread(26767): at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
05-17 14:58:53.010: E/ActivityThread(26767): at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
05-17 14:58:53.010: E/ActivityThread(26767): at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
05-17 14:58:53.010: E/ActivityThread(26767): at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
05-17 14:58:53.010: E/ActivityThread(26767): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:212)
05-17 14:58:53.010: E/ActivityThread(26767): at android.app.Activity.setContentView(Activity.java:1657)
05-17 14:58:53.010: E/ActivityThread(26767): at com.example.pincode.PinCodeActivity.onCreate(PinCodeActivity.java:26)
05-17 14:58:53.010: E/ActivityThread(26767): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-17 14:58:53.010: E/ActivityThread(26767): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1722)
05-17 14:58:53.010: E/ActivityThread(26767): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1784)
05-17 14:58:53.010: E/ActivityThread(26767): at android.app.ActivityThread.access$1500(ActivityThread.java:123)
05-17 14:58:53.010: E/ActivityThread(26767): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
05-17 14:58:53.010: E/ActivityThread(26767): at android.os.Handler.dispatchMessage(Handler.java:99)
05-17 14:58:53.010: E/ActivityThread(26767): at android.os.Looper.loop(Looper.java:130)
05-17 14:58:53.010: E/ActivityThread(26767): at android.app.ActivityThread.main(ActivityThread.java:3835)
05-17 14:58:53.010: E/ActivityThread(26767): at java.lang.reflect.Method.invokeNative(Native Method)
05-17 14:58:53.010: E/ActivityThread(26767): at java.lang.reflect.Method.invoke(Method.java:507)
05-17 14:58:53.010: E/ActivityThread(26767): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847)
05-17 14:58:53.010: E/ActivityThread(26767): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605)
05-17 14:58:53.010: E/ActivityThread(26767): at dalvik.system.NativeStart.main(Native Method)
05-17 14:58:53.010: E/ActivityThread(26767): Caused by: java.lang.reflect.InvocationTargetException
05-17 14:58:53.010: E/ActivityThread(26767): at java.lang.reflect.Constructor.constructNative(Native Method)
05-17 14:58:53.010: E/ActivityThread(26767): at java.lang.reflect.Constructor.newInstance(Constructor.java:415)
05-17 14:58:53.010: E/ActivityThread(26767): at android.view.LayoutInflater.createView(LayoutInflater.java:505)
05-17 14:58:53.010: E/ActivityThread(26767): ... 21 more
05-17 14:58:53.010: E/ActivityThread(26767): Caused by: java.lang.NoSuchMethodError: android.widget.LinearLayout.<init>
05-17 14:58:53.010: E/ActivityThread(26767): at com.example.customviews.CustomView.<init>(CustomView.java:98)
05-17 14:58:53.010: E/ActivityThread(26767): at com.example.customviews.CustomView.<init>(CustomView.java:94)
05-17 14:58:53.010: E/ActivityThread(26767): ... 24 more
我无法理解调用super(context, attrs, defStyle)
时导致InflateException的原因。我也尝试了super(context, attrs, 0)
,但这没有用,这真的很奇怪,因为即使是LinearLayout也使用它,就像我检查过的源代码的大多数其他视图一样。
答案 0 :(得分:13)
我在Android开发者Google网上找到了这个答案:
LinearLayout构造函数的三参数版本是唯一的 适用于API 11及更高版本 - 即Android 3.0。
这种依赖关系必须在运行时由实际的Android来满足 在设备上运行的版本。
我在运行Gingerbread(2.3.3)的手机上进行测试。果然,当我在带有ICS(4.0.3)的仿真器上运行程序时,它工作正常。仍在寻找一种解决方法,以便我可以在预蜂窝上使用我的代码。
答案 1 :(得分:0)
您的构造函数正在调用this
而不是super
。如果你改变了,那就可以了。
我刚刚使用构造函数扩展了线性布局,以测试它的工作原理。
答案 2 :(得分:0)
我也遇到了自定义LinearLayout的这个问题。我所做的是在构造函数中调用super
而不是this
,并在单独的方法中设置属性。
public class CustomView extends LinearLayout {
public CustomView(Context context) {
super(context);
}
public CustomView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
setAttributes(attrs);
}
private void setAttributes(AttributeSet attrs) {
/* set custom attributes with TypedArray */
}
/* other methods */
}