如何为LinearLayout（适用于Android键盘）充气？

Question

I'm trying to create an android keyboard, right now I want it just to inflate, ie show, linearlayout from main.xml

Here's the java file

package keyboard.rob.com;

import ...

public class zyz extends InputMethodService 
implements KeyboardView.OnKeyboardActionListener {

    private KeyboardView mInputView;

    @Override public void onCreate() {
        super.onCreate();
    }

    @Override public View onCreateInputView() {
        mInputView = (KeyboardView) getLayoutInflater().inflate(R.layout.main, null);
        return mInputView;
    }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>


<LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android" android:layout_gravity="center" android:id="@+id/LL_whole" android:orientation="vertical" android:clickable="false">


    <LinearLayout android:layout_width="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android" android:background="@layout/backrep" android:layout_gravity="center" android:id="@+id/LL_total" android:orientation="vertical" android:layout_height="wrap_content">
        <LinearLayout android:layout_height="wrap_content" android:layout_width="match_parent" android:background="@drawable/spell_frame" android:layout_marginBottom="10px" android:layout_marginTop="5px" android:layout_gravity="center" android:id="@+id/LL_spell" android:paddingLeft="10px">
        </LinearLayout>


        <LinearLayout android:layout_height="wrap_content" android:orientation="horizontal" android:layout_gravity="center" android:layout_width="wrap_content" android:id="@+id/LLrow1">

        </LinearLayout>
        <LinearLayout android:layout_height="wrap_content" android:layout_gravity="center" android:orientation="horizontal" android:layout_width="wrap_content" android:id="@+id/LLrow2"></LinearLayout>
        <LinearLayout android:layout_height="wrap_content" android:layout_gravity="center" android:orientation="horizontal" android:layout_width="wrap_content" android:id="@+id/LLrow3"></LinearLayout>
        <LinearLayout android:layout_height="wrap_content" android:layout_gravity="center" android:orientation="horizontal" android:layout_width="wrap_content" android:id="@+id/LLrow4">
        </LinearLayout>

    </LinearLayout>


</LinearLayout>

and the error it crashes with:

08-29 20:21:28.128: ERROR/AndroidRuntime(10227): java.lang.ClassCastException: android.widget.LinearLayout

Any ideas? Thanks!

Answer 1

try below code..

package keyboard.rob.com;

import ...

public class TotalKeyboard extends InputMethodService 
implements KeyboardView.OnKeyboardActionListener {

    private LinearLayout mInputView;

    @Override public void onCreate() {
        super.onCreate();
    }

    @Override public View onCreateInputView() {
        mInputView = (LinearLayout) getLayoutInflater().inflate(R.layout.main, null);
        return mInputView;
    }
}

Answer 2

You're casting your layout, which basically is a LinearLayout , to a KeyboardView . This gives you a classcast exception. Since onCreateInputView() returns a View , it should suffice to remove the cast. LayoutInflater.inflate() already returns a View . No need to cast it to anything. ( LinearLayout extends the View class, so it's valid in this case)

So try changing

mInputView = (KeyboardView) getLayoutInflater().inflate(R.layout.main, null);

to

mInputView = getLayoutInflater().inflate(R.layout.main, null);

Alternatively you can cast it to a LinearLayout , but thats unneccesary here.