LinearLayout $LayoutParams无法强制转换为android.support.v4.widget.DrawerLayout $LayoutParams

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我正在尝试做导航抽屉选项.

这是我的xml:

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <android.support.v4.widget.DrawerLayout
  3. xmlns:android="http://schemas.android.com/apk/res/android"
  4. android:id="@+id/drawer_layout"
  5. android:layout_width="match_parent"
  6. android:layout_height="match_parent">
  7. <LinearLayout
  8. android:layout_width="match_parent"
  9. android:layout_height="wrap_content"
  10. android:orientation="vertical">
  11. <Button
  12. android:id="@+id/sendnewmessages"
  13. android:layout_width="wrap_content"
  14. android:layout_height="30dp"
  15. android:background="@drawable/nothere"
  16. android:gravity="center_horizontal"
  17. android:shadowColor="@android:color/black"
  18. android:shadowDx="1"
  19. android:shadowDy="1"
  20. android:shadowRadius="1"
  21. android:text="Send New Messages"
  22. android:textAlignment="center"
  23. android:textColor="@android:color/black" />
  24. <EditText
  25. android:id="@+id/searchmessage"
  26. android:layout_height="40dp"
  27. android:layout_width="200dp"
  28. android:gravity="center"
  29. android:hint="Search Messages"/>
  30. <ListView
  31. android:id="@+id/listview"
  32. android:layout_width="match_parent"
  33. android:layout_height="wrap_content">
  34. </ListView>
  35. <ListView android:id="@+id/left_drawer"
  36. android:layout_width="240dp"
  37. android:layout_height="match_parent"
  38. android:layout_gravity="start"
  39. android:choiceMode="singleChoice"
  40. android:divider="@android:color/transparent"
  41. android:dividerHeight="0dp"
  42. android:background="#111"/>
  43. </LinearLayout>
  44. </android.support.v4.widget.DrawerLayout>

如果我删除Linearlayout则没有错误.此按钮出现在listview后面,edittext出现在屏幕中间.问题是对象没有对齐.有没有办法在DrawerLayout中对齐视图对象?

如果我不删除linearlayout,我会收到此错误

  1. LinearLayout$LayoutParams cannot be cast to android.support.v4.widget.DrawerLayout$LayoutParams

堆栈跟踪:

E/AndroidRuntime(3454): FATAL EXCEPTION: main Process: com.brilliant.bridge,PID: 3454 java.lang.ClassCastException:
android.widget.LinearLayout$LayoutParams cannot be cast to
android.support.v4.widget.DrawerLayout$LayoutParams at
android.support.v4.widget.DrawerLayout.isDrawerView(DrawerLayout.java:910)
at
android.support.v4.widget.DrawerLayout.isDrawerOpen(DrawerLayout.java:1156)
at
com.brilliant.bridge.AdminMessages.onPrepareOptionsMenu(AdminMessages.java:220)
at android.app.Activity.onPreparePanel(Activity.java:2556) at
com.android.internal.policy.impl.PhoneWindow.preparePanel(PhoneWindow.java:464)
at
com.android.internal.policy.impl.PhoneWindow.doInvalidatePanelMenu(PhoneWindow.java:800)
at
com.android.internal.policy.impl.PhoneWindow$1.run(PhoneWindow.java:221)
at
android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
at android.view.Choreographer.doCallbacks(Choreographer.java:574) at
android.view.Choreographer.doFrame(Choreographer.java:543) at
android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
at android.os.Handler.handleCallback(Handler.java:733) at
android.os.Handler.dispatchMessage(Handler.java:95) at
android.os.Looper.loop(Looper.java:136) at
android.app.ActivityThread.main(ActivityThread.java:5017) at
java.lang.reflect.Method.invokeNative(Native Method) at
java.lang.reflect.Method.invoke(Method.java:515) at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) at
dalvik.system.NativeStart.main(Native Method)

  1. public boolean onPrepareOptionsMenu(Menu menu) {
  2.  
  3. boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
  4. menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
  5. return super.onPrepareOptionsMenu(menu);
  6. }

解决方法

在xml文件中为LinearLayout分配一个ID:
  1. <LinearLayout
  2. android:id="@+id/DrawerLinear"
  3. android:layout_width="match_parent"
  4. android:layout_height="wrap_content"
  5. android:orientation="vertical">
  6.  
  7. <!-- YOUR LISTVIEW IS HERE -->
  8. </LinearLayout>

然后在你的java类中,抛出这个LinearLayout:

  1. private LinearLayout DrawerLinear;

在OnCreate中你应该这样做:

  1. DrawerLinear = (LinearLayout) findViewById(R.id.DrawerLinear);

在你的onPrepareOptionMenu中,把这个:

  1. public boolean onPrepareOptionsMenu(Menu menu) {
  2.  
  3. boolean drawerOpen = mDrawerLayout.isDrawerOpen(DrawerLinear);
  4. menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
  5. return super.onPrepareOptionsMenu(menu);
  6. }

它应该解决你的问题.

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