android - LinearLayout$LayoutParams 无法转换为 android.support.v4.widget.DrawerLayout$LayoutParams

Question

我正在尝试做抽屉导航选项。

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 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 View 对象？

如果我不删除 linearlayout 我会得到这个错误:

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)

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 文件中为您的 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，转换这个 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);
}

它应该可以解决您的问题。