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

Question

我正在尝试做导航抽屉选项.

这是我的xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <Button
             android:id="@+id/sendnewmessages"
             android:layout_width="wrap_content"
             android:layout_height="30dp"
             android:background="@drawable/nothere"
             android:gravity="center_horizontal"
             android:shadowColor="@android:color/black"
             android:shadowDx="1"
             android:shadowDy="1"
             android:shadowRadius="1"
             android:text="Send New Messages"
             android:textAlignment="center"
             android:textColor="@android:color/black" />
        <EditText
             android:id="@+id/searchmessage"
             android:layout_height="40dp"
             android:layout_width="200dp"
             android:gravity="center"
             android:hint="Search Messages"/>
        <ListView
            android:id="@+id/listview"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
        </ListView>
        <ListView android:id="@+id/left_drawer"
            android:layout_width="240dp"
            android:layout_height="match_parent"
            android:layout_gravity="start"
            android:choiceMode="singleChoice"
            android:divider="@android:color/transparent"
            android:dividerHeight="0dp"
            android:background="#111"/>
    </LinearLayout>
</android.support.v4.widget.DrawerLayout>

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

如果我不删除,linearlayout我会收到此错误:

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

堆栈跟踪:

E/AndroidRuntime(3454):FATAL EXCEPTION:main进程:com.brilliant.bridge,PID:3454 java.lang.ClassCastException:android.widget.LinearLayout $ LayoutParams无法强制转换为android.support.v4.widget.DrawerLayout $ LayoutParams在android.support.v4.widget.DrawerLayout.isDrawerView(DrawerLayout.java:910)的android.support.v4.widget.DrawerLayout.isDrawerOpen(DrawerLayout.java:1156)com.brilliant.bridge.AdminMessages.onPrepareOptionsMenu(AdminMessages) .java:220)在com.android.internal.policy的com.android.internal.policy.impl.PhoneWindow.preparePanel(PhoneWindow.java:464)的android.app.Activity.onPreparePanel(Activity.java:2556).位于android.view.Choreographer的com.android.internal.policy.impl.PhoneWindow $ 1.run(PhoneWindow.java:221)中的impl.PhoneWindow.doInvalidatePanelMenu(PhoneWindow.java:800)$ CallbackRecord.run(Choreographer.java:761 )在Android.view.Chore上的android.view.Choreographer.doCrame(Choreographer.java:544)的android.view.Chore上的android.view.Choreographer.doCallbacks(Choreographer.java:544)ographer $ FrameDisplayEventReceiver.run(Choreographer.java:747)在android.os.Handler.handleCallback(Handler.java:733)android.os.Handler.dispatchMessage(Handler.java:95)android.os.Looper.loop (Looper.java:136)位于java.lang.reflect.Method.invoke(Method.java)java.lang.reflect.Method.invokeNative(Native Method)的android.app.ActivityThread.main(ActivityThread.java:5017) :515)at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:779)位于dalvik.system.NativeStart的com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595). main(原生方法)

public boolean onPrepareOptionsMenu(Menu menu) {

    boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
    menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
    return super.onPrepareOptionsMenu(menu);
}

Answer 1

在xml文件中为LinearLayout分配一个ID:

<LinearLayout
        android:id="@+id/DrawerLinear"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <!-- YOUR LISTVIEW IS HERE -->
</LinearLayout>

然后在你的java类中,抛出这个LinearLayout:

private LinearLayout    DrawerLinear;

在OnCreate中你应该这样做:

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

在你的onPrepareOptionMenu中,把这个:

public boolean onPrepareOptionsMenu(Menu menu) {

    boolean drawerOpen = mDrawerLayout.isDrawerOpen(DrawerLinear);
    menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
    return super.onPrepareOptionsMenu(menu);
}

它应该解决你的问题.