设置图像按钮的背景时解析错误

Question

Hi I am trying to create a custom button. The button has basically two modes, pressed and not pressed. I have created an xml file named addtransaction which holds the two button images, the code is as follows

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/add_transaction_after" android:state_pressed="true"></item>
    <item android:drawable="@drawable/add_transaction_before"   android:state_focused="false"></item>
</selector>

The problem I am facing is that, when the button corresponding to which the xml file is created is assigned the background. The following message appears

Failed to parse file/Users/Rudi/Desktop/ABC/res/drawable/addtransaction.xml

I am able to provide customisation to other buttons, but only this xml file is showing errors. Can some one tell me what I am doing wrong?

And as an edit, here is the code for the xml file which holds my buttons

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:baselineAligned="false"
    android:layout_gravity="center"
    android:orientation="horizontal"
    android:weightSum="10" >

    <LinearLayout
        android:id="@+id/mainLayout"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:layout_weight="6"
        android:background="@drawable/background"
        android:gravity="center"
        android:orientation="vertical" >

        <ImageButton
            android:id="@+id/addAccount"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/account"
            android:gravity="center" />
        <ImageButton
            android:id="@+id/addTransaction"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/addtransaction"
            android:gravity="center" />
        <ImageButton
            android:id="@+id/viewAccount"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/viewaccount"
            android:gravity="center" />
        <ImageButton
            android:id="@+id/recentTransaction"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/viewtransaction"
            android:gravity="center" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="4" >
    </LinearLayout>

</LinearLayout>

here are the errors which log cat displays.

10-26 20:26:02.836: E/ActivityThread(4454): **Failed to inflate
10-26 20:26:02.836: E/ActivityThread(4454): android.view.InflateException: Binary XML file line #28: Error inflating class <unknown>**
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.createView(LayoutInflater.java:613)
10-26 20:26:02.836: E/ActivityThread(4454):     at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:56)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.onCreateView(LayoutInflater.java:660)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:685)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
10-26 20:26:02.836: E/ActivityThread(4454):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.app.Activity.setContentView(Activity.java:1867)
10-26 20:26:02.836: E/ActivityThread(4454):     at com.code.accountmanager.AccountManagerActivity.onCreate(AccountManagerActivity.java:41)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.app.Activity.performCreate(Activity.java:5008)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2141)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2212)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.app.ActivityThread.access$600(ActivityThread.java:144)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.os.Handler.dispatchMessage(Handler.java:99)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.os.Looper.loop(Looper.java:137)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.app.ActivityThread.main(ActivityThread.java:4965)
10-26 20:26:02.836: E/ActivityThread(4454):     at java.lang.reflect.Method.invokeNative(Native Method)
10-26 20:26:02.836: E/ActivityThread(4454):     at java.lang.reflect.Method.invoke(Method.java:511)
10-26 20:26:02.836: E/ActivityThread(4454):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
10-26 20:26:02.836: E/ActivityThread(4454):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
10-26 20:26:02.836: E/ActivityThread(4454):     at dalvik.system.NativeStart.main(Native Method)
10-26 20:26:02.836: E/ActivityThread(4454): Caused by: java.lang.reflect.InvocationTargetException
10-26 20:26:02.836: E/ActivityThread(4454):     at java.lang.reflect.Constructor.constructNative(Native Method)
10-26 20:26:02.836: E/ActivityThread(4454):     at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.LayoutInflater.createView(LayoutInflater.java:587)
10-26 20:26:02.836: E/ActivityThread(4454):     ... 25 more
10-26 20:26:02.836: E/ActivityThread(4454): **Caused by: android.content.res.Resources$NotFoundException: File res/drawable/transaction.xml from drawable resource ID #0x7f02000f**
10-26 20:26:02.836: E/ActivityThread(4454):     at android.content.res.Resources.loadDrawable(Resources.java:1947)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.content.res.TypedArray.getDrawable(TypedArray.java:601)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.view.View.<init>(View.java:3336)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.widget.ImageView.<init>(ImageView.java:114)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.widget.ImageButton.<init>(ImageButton.java:87)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.widget.ImageButton.<init>(ImageButton.java:83)
10-26 20:26:02.836: E/ActivityThread(4454):     ... 28 more
10-26 20:26:02.836: E/ActivityThread(4454): **Caused by: java.lang.NullPointerException
10-26 20:26:02.836: E/ActivityThread(4454):     at android.graphics.drawable.DrawableContainer$DrawableContainerState.addChild(DrawableContainer.java:524)**
10-26 20:26:02.836: E/ActivityThread(4454):     at android.graphics.drawable.StateListDrawable$StateListState.addStateSet(StateListDrawable.java:278)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.graphics.drawable.StateListDrawable.inflate(StateListDrawable.java:186)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.graphics.drawable.Drawable.createFromXmlInner(Drawable.java:881)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.graphics.drawable.Drawable.createFromXml(Drawable.java:818)
10-26 20:26:02.836: E/ActivityThread(4454):     at android.content.res.Resources.loadDrawable(Resources.java:1944)
10-26 20:26:02.836: E/ActivityThread(4454):     ... 33 more

Answer 1

Try adding:

<item android:drawable="@drawable/some_drawable" />

If this doesn't help, try these steps:

1. Remove the library declaration of the project.
2. Open the layout causing the error (the one which using the selector) in graphical layout.
3. Clean the project (Project -> Clean)
4. Close and reopen eclipse. (the layout should be ok now)
5. You can set the project as library again.

Here's original answer.

Answer 2

You say your drawable xml is named addtransaction.xml - in your layout file you reference it as @drawable/trans -

So change that line to android:background="@drawable/addtransaction" and you should be done.

Answer 3

事实证明图像本身存在一些错误，再次制作了图像，将其用作按钮的背景并且没有解析错误。