Java 单击按钮时出现AnimationDrawable错误

我相信我的xml是正确的，但我不确定是什么原因导致了代码中的这个错误。我试图在imagebutton上尝试animationdrawable，但每次单击按钮时都会出错

这是我的动画列表“音乐图标”：

my layout.xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="wrap_content" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".HomeScreen"
    android:background="@android:drawable/screen_background_dark_transparent"
    android:clickable="true"
    android:id="@+id/homescreen_view">

    <Button
        android:layout_width="100.0dp"
        android:layout_height="25.0dp"
        android:text="Help"
        android:id="@+id/instructionsButton"
        android:layout_alignParentTop="false"
        android:layout_alignParentStart="true"
        android:textColor="#05ffda"
        android:background="@android:color/holo_purple"
        android:longClickable="true" />

    <ImageButton
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:scaleType="centerCrop"
        android:id="@+id/soundEnable_button"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:longClickable="true"
        android:nestedScrollingEnabled="true"/>

    <Button
        style="?android:attr/buttonStyleSmall"
        android:layout_width="100dp"
        android:layout_height="25dp"
        android:text="Highscores"
        android:id="@+id/highscores_button"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:background="@android:color/holo_purple"
        android:textColor="#05ffda" />

    <Button
        style="?android:attr/buttonStyleSmall"
        android:layout_width="100dp"
        android:layout_height="30dp"
        android:text="Play Game"
        android:id="@+id/startGame_button"
        android:background="@android:color/holo_purple"
        android:textColor="#05ffda"
        android:layout_marginTop="175dp"
        android:singleLine="true"
        android:layout_alignParentTop="false"
        android:layout_centerHorizontal="true" />

</RelativeLayout>

2件事：

更改您的可绘图项（删除

selector

tag）：

我看不到您正在设置

musicEnable\u ImageButton

的背景，您只想

获取它。。。是我遗漏了什么，还是你一开始就忘了设置背景

---

StateListDrawable无法强制转换为android.graphics.drawable.AnimationDrawable

请原谅，我是新手，但“选择器标签”是什么？关于背景设置，“setImageResource”与setBackgroundResource是否不同？你能提供一个例子吗？如果你把你发布的drawable与我发布的drawable进行比较，你会发现封装的东西不再是

选择器

，而是

动画列表

本身

setImageResource

和

setBackgroundResource

是两个完全不同的东西。这是

ImageView

的一个重要部分。删除了选择器标记并更改为setImageResource，但我仍然收到相同的错误。“更改为setImageResource”？我的原始：final AnimationDrawable frameAnimation=（AnimationDrawable）musicEnable_ImageButton.getBackground（）；musicEnable_ImageButton.setBackgroundResource（R.drawable.music_图标）；我的更改：final AnimationDrawable frameAnimation=（AnimationDrawable）musicEnable_ImageButton.getBackground（）；musicEnable_ImageButton.setImageResource（R.drawable.music_图标）；我觉得我误解了你的第二个建议。

import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageButton;
import android.graphics.drawable.AnimationDrawable;


public class HomeScreen extends AppCompatActivity {

ImageButton musicEnable_ImageButton;
Handler musicIcon_animate = new Handler();
int ArrayPos = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home_screen);

    musicEnable_ImageButton = (ImageButton) findViewById(R.id.soundEnable_button);
    musicEnable_ImageButton.setBackgroundResource(R.drawable.musicoff);
    musicEnable_ImageButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            musicEnable_ImageButton.setBackgroundResource(R.drawable.music_icon);
            final AnimationDrawable frameAnimation = (AnimationDrawable) musicEnable_ImageButton.getBackground();
            frameAnimation.start();
        }
    });
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="wrap_content" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".HomeScreen"
    android:background="@android:drawable/screen_background_dark_transparent"
    android:clickable="true"
    android:id="@+id/homescreen_view">

    <Button
        android:layout_width="100.0dp"
        android:layout_height="25.0dp"
        android:text="Help"
        android:id="@+id/instructionsButton"
        android:layout_alignParentTop="false"
        android:layout_alignParentStart="true"
        android:textColor="#05ffda"
        android:background="@android:color/holo_purple"
        android:longClickable="true" />

    <ImageButton
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:scaleType="centerCrop"
        android:id="@+id/soundEnable_button"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:longClickable="true"
        android:nestedScrollingEnabled="true"/>

    <Button
        style="?android:attr/buttonStyleSmall"
        android:layout_width="100dp"
        android:layout_height="25dp"
        android:text="Highscores"
        android:id="@+id/highscores_button"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:background="@android:color/holo_purple"
        android:textColor="#05ffda" />

    <Button
        style="?android:attr/buttonStyleSmall"
        android:layout_width="100dp"
        android:layout_height="30dp"
        android:text="Play Game"
        android:id="@+id/startGame_button"
        android:background="@android:color/holo_purple"
        android:textColor="#05ffda"
        android:layout_marginTop="175dp"
        android:singleLine="true"
        android:layout_alignParentTop="false"
        android:layout_centerHorizontal="true" />

</RelativeLayout>

06-07 05:00:48.004 19844-19844/com.example.comp.app_name E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.ClassCastException: android.graphics.drawable.StateListDrawable cannot be cast to android.graphics.drawable.AnimationDrawable
at com.example.comp.app_name.HomeScreen$1.onClick(HomeScreen.java:36)
at android.view.View.performClick(View.java:4240)
at android.view.View$PerformClick.run(View.java:17721)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)

<animation-list xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/selected" android:oneshot="true">
    <item android:drawable="@drawable/musicon1" android:duration="50" />
    <item android:drawable="@drawable/musicon2" android:duration="50" />
    <item android:drawable="@drawable/musicon3" android:duration="50" />
    <item android:drawable="@drawable/musicon4" android:duration="50" />
    <item android:drawable="@drawable/musicon5" android:duration="50" />
</animation-list>