我有一个Actionbar和一些片段.问题是我的主屏幕.有一个概述左侧的片段和右侧的细节片段.我的TabListener是动态的,所以我想以编程方式设置我的布局的重量.每当我尝试获取我的LinearLayout的Layoutparams我得到一个ClassCastException：
12-22 16:00:37.620: W/System.err(7235): java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.widget.LinearLayout$LayoutParams 12-22 16:00:37.625: W/System.err(7235): at com.coover.eu.lostandfound.ListSearchFragment.onViewCreated(ListSearchFragment.java:184) 12-22 16:00:37.625: W/System.err(7235): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:884) 12-22 16:00:37.630: W/System.err(7235): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1080) 12-22 16:00:37.630: W/System.err(7235): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:622) 12-22 16:00:37.630: W/System.err(7235): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1416) 12-22 16:00:37.630: W/System.err(7235): at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:505) 12-22 16:00:37.630: W/System.err(7235): at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1178) 12-22 16:00:37.635: W/System.err(7235): at android.app.Activity.performStart(Activity.java:5216) 12-22 16:00:37.635: W/System.err(7235): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2083) 12-22 16:00:37.635: W/System.err(7235): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135) 12-22 16:00:37.635: W/System.err(7235): at android.app.ActivityThread.access$700(ActivityThread.java:140) 12-22 16:00:37.635: W/System.err(7235): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1237) 12-22 16:00:37.640: W/System.err(7235): at android.os.Handler.dispatchMessage(Handler.java:99) 12-22 16:00:37.640: W/System.err(7235): at android.os.Looper.loop(Looper.java:137) 12-22 16:00:37.640: W/System.err(7235): at android.app.ActivityThread.main(ActivityThread.java:4921) 12-22 16:00:37.640: W/System.err(7235): at java.lang.reflect.Method.invokeNative(Native Method) 12-22 16:00:37.640: W/System.err(7235): at java.lang.reflect.Method.invoke(Method.java:511) 12-22 16:00:37.645: W/System.err(7235): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038) 12-22 16:00:37.645: W/System.err(7235): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805) 12-22 16:00:37.645: W/System.err(7235): at dalvik.system.NativeStart.main(Native Method)
膨胀的布局：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="@+id/container_found_list_overview">
<EditText android:id="@+id/search_Box"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:padding="5dp"
android:textSize="35sp"
android:hint="@string/search"
android:inputType="text"
android:maxLines="1"/>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/overview_list_view">
</ListView>
</LinearLayout>
代码：
LinearLayout myView = (LinearLayout)this.getView().findViewById(R.id.container_found_list_overview);
Log.d("found container",""+(myView != null));
try{
LayoutParams lp = (LayoutParams) myView.getLayoutParams();
lp.weight = 1;
lp.width = 0;
myView.setLayoutParams(lp);
}
catch(RuntimeException e){
Log.e("cant get layoutparams",e.getMessage());
e.printStackTrace();
}
解决方法
发生的是一个视图的LayoutParams实际上是父类的类型.在这种情况下,您将获得一个FrameLayout $LayoutParams,因为您的LinearLayout位于FrameLayout中.
为什么是父母的类型？这是因为他们存储对父母有用的信息.如果要检索EditText或ListView的布局参数,您将获得LinearLayout $LayoutParams.
