我是Android新手，我在布局背景中播放动画.gif文件时遇到问题。当我运行应用程序时，背景是动画.gif的单帧，就像图片一样。我主要在两个方面做过研究：
下面的链接是我得到最多帮助的地方。
下面的链接让我觉得我收到的错误与设置为private，public或protected的类有关。
这是守则---------------------------------------------- -------------------------------------------------- -------------------
错误由:: ERROR＃::表示，代码下方有完整描述。
import java.io.InputStream;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Movie;
import android.view.Menu;
import android.view.View;
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(new MYGIFView()); :: ERROR 1 ::
}
}
private class MYGIFView extends View{ :: ERROR 2 ::
Movie movie,movie1;
InputStream is=null , is1=null;
long moviestart;
public GIFView(Context context) { :: ERROR 3 ::
super(context); :: ERROR 4 ::
is=context.getResources().openRawResource(R.drawable.swing);
movie=Movie.decodeStream(is);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
super.onDraw(canvas);
long now=android.os.SystemClock.uptimeMillis();
System.out.println("now="+now);
if (moviestart == 0) { // first time
moviestart = now;
}
System.out.println("\tmoviestart="+moviestart);
int relTime = (int)((now - moviestart) % movie.duration()) ;
System.out.println("time="+relTime+"\treltime="+movie.duration());
movie.setTime(relTime);
movie.draw(canvas,this.getWidth()/2-20,this.getHeight()/2-40);
this.invalidate();
}
}
:: ERRORS LIST :: ERRORS LIST ::错误列表::错误列表::错误列表::错误列表::
::错误1 ::构造函数MYGIFView（）不可见
::错误2 ::隐式超级构造函数View（）未定义为可见构造函数
::错误3 ::缺少方法的返回类型
:: ERROR 4 ::构造函数调用必须是构造函数中的第一个语句
.
.
---------- UPDATE --------- UPDATE ------------ UPDATE --------------- UPDATE ------------- UPDATE ---------- UPDATE --------- UPDATE ------------ UPDATE - -------------更新-------------更新---------更新
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.
我创建了动画列表= res / drawable-hdpi / progress_animation.xml
<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/selected" android:oneshot="false">
<item android:drawable="@drawable/frame02" android:duration="50" />
<item android:drawable="@drawable/frame03" android:duration="50" />
<item android:drawable="@drawable/frame04" android:duration="50" />
<item android:drawable="@drawable/frame05" android:duration="50" />
<item android:drawable="@drawable/frame06" android:duration="50" />
<item android:drawable="@drawable/frame07" android:duration="50" />
<item android:drawable="@drawable/frame08" android:duration="50" />
<item android:drawable="@drawable/frame09" android:duration="50" />
<item android:drawable="@drawable/frame10" android:duration="50" />
.........................................
<item android:drawable="@drawable/frame57" android:duration="50" />
<item android:drawable="@drawable/frame58" android:duration="50" />
</animation-list>
.
.
我创建了布局文件来托管Image View = res / layout / activity_main.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="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<ImageView android:id="@+id/swing_play" android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</RelativeLayout>
.
Java Class Activity调用ImageView和AnimationDrawable = com.example.apptwo / MainActivity.java
.
package com.exampleone.apptwo;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.drawable.AnimationDrawable;
import android.view.Menu;
import android.widget.ImageView;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.acivity_main);
ImageView img = (ImageView)findViewById(R.id.swing_play);
img.setBackgroundResource(R.drawable.progress_animation);
AnimationDrawable frameAnimation = (AnimationDrawable) img.getBackground();
frameAnimation.start();
}
}
.
IDE不会在代码中标记任何错误。但是，当我运行应用程序时，我的模拟器显示一个白色背景，并显示消息“不幸的是，AppTwo已停止”。
ErrorLog读取=“未处理的事件循环异常”
LOGCAT ------------------------------------------------- -------------------------------------------------- --------------------------------
这是会话过滤器LOGCAT
04-06 17:10:48.193: D/AndroidRuntime(989): Shutting down VM
04-06 17:10:48.193: W/dalvikvm(989): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
04-06 17:10:48.213: E/AndroidRuntime(989): FATAL EXCEPTION: main
04-06 17:10:48.213: E/AndroidRuntime(989): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.apptwo/com.example.apptwo.MainActivity}: java.lang.NullPointerException
04-06 17:10:48.213: E/AndroidRuntime(989): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.app.ActivityThread.access$600(ActivityThread.java:141)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.os.Handler.dispatchMessage(Handler.java:99)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.os.Looper.loop(Looper.java:137)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-06 17:10:48.213: E/AndroidRuntime(989): at java.lang.reflect.Method.invokeNative(Native Method)
04-06 17:10:48.213: E/AndroidRuntime(989): at java.lang.reflect.Method.invoke(Method.java:511)
04-06 17:10:48.213: E/AndroidRuntime(989): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-06 17:10:48.213: E/AndroidRuntime(989): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-06 17:10:48.213: E/AndroidRuntime(989): at dalvik.system.NativeStart.main(Native Method)
04-06 17:10:48.213: E/AndroidRuntime(989): Caused by: java.lang.NullPointerException
04-06 17:10:48.213: E/AndroidRuntime(989): at com.example.apptwo.MainActivity.onCreate(MainActivity.java:14)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.app.Activity.performCreate(Activity.java:5104)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
04-06 17:10:48.213: E/AndroidRuntime(989): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
04-06 17:10:48.213: E/AndroidRuntime(989): ... 11 more
要发布的LogCat（所有消息）太多，但下面的这个消息似乎在错误发生时很重要。
04-06 17:10:48.213: E/AndroidRuntime(989): FATAL EXCEPTION: main
.
包含内容视图的LOGCAT更新！ ！ ！
: error opening trace file: No such file or directory (2)
: GC_FOR_ALLOC freed 67K, 7% free 2500K/2688K, paused 49ms, total 54ms
: I/dalvikvm-heap(1813): Grow heap (frag case) to 4.022MB for 1536016-byte allocation
: D/dalvikvm(1813): GC_FOR_ALLOC freed 2K, 5% free 3998K/4192K, paused 125ms, total 125ms
: D/dalvikvm(1813): GC_CONCURRENT freed <1K, 5% free 3998K/4192K, paused 5ms+15ms, total 105ms
: D/dalvikvm(1813): GC_FOR_ALLOC freed <1K, 5% free 3998K/4192K, paused 36ms, total 37ms
: Grow heap (frag case) to 5.485MB for 1536016-byte allocation
: GC_CONCURRENT freed <1K, 4% free 5498K/5696K, paused 75ms+14ms, total 156ms
: GC_FOR_ALLOC freed <1K, 4% free 5499K/5696K, paused 32ms, total 33ms
: Grow heap (frag case) to 6.950MB for 1536016-byte allocation
: GC_CONCURRENT freed <1K, 3% free 6999K/7200K, paused 74ms+17ms, total 156ms
: D/dalvikvm(1813): GC_FOR_ALLOC freed <1K, 3% free 6999K/7200K, paused 46ms, total 47ms
: I/dalvikvm-heap(1813): Grow heap (frag case) to 8.416MB for 1536016-byte allocation
: GC_CONCURRENT freed <1K, 3% free 8499K/8704K, paused 79ms+4ms, total 173ms
: GC_FOR_ALLOC freed <1K, 3% free 10001K/10208K, paused 33ms, total 34ms
: GC_FOR_ALLOC freed <1K, 2% free 11501K/11712K, paused 35ms, total 35ms
: GC_FOR_ALLOC freed <1K, 2% free 13002K/13216K, paused 38ms, total 38ms
: GC_FOR_ALLOC freed <1K, 2% free 14503K/14720K, paused 35ms, total 36ms
: GC_FOR_ALLOC freed <1K, 2% free 16003K/16224K, paused 39ms, total 40ms
: GC_FOR_ALLOC freed <1K, 2% free 17504K/17728K, paused 41ms, total 41ms
: GC_FOR_ALLOC freed <1K, 2% free 19004K/19232K, paused 42ms, total 43ms
: GC_FOR_ALLOC freed <1K, 2% free 20505K/20736K, paused 58ms, total 58ms
: GC_FOR_ALLOC freed <1K, 2% free 22006K/22240K, paused 137ms, total 138ms
: GC_FOR_ALLOC freed <1K, 1% free 23506K/23744K, paused 47ms, total 47ms
: GC_FOR_ALLOC freed <1K, 1% free 25007K/25248K, paused 48ms, total 48ms
: GC_FOR_ALLOC freed <1K, 1% free 26507K/26752K, paused 50ms, total 51ms
: GC_FOR_ALLOC freed <1K, 1% free 28008K/28256K, paused 56ms, total 57ms
: GC_FOR_ALLOC freed <1K, 1% free 29509K/29760K, paused 58ms, total 58ms
: Clamp target GC heap from 32.398MB to 32.000MB
: GC_FOR_ALLOC freed <1K, 1% free 31009K/31264K, paused 57ms, total 58ms
: Clamp target GC heap from 33.863MB to 32.000MB
: GC_FOR_ALLOC freed <1K, 1% free 32510K/32768K, paused 56ms, total 56ms
: Forcing collection of SoftReferences for 1536016-byte allocation
:Clamp target GC heap from 33.855MB to 32.000MB
: GC_BEFORE_OOM freed 9K, 1% free 32500K/32768K, paused 87ms, total 88ms
: Out of memory on a 1536016-byte allocation.
: "main" prio=5 tid=1 RUNNABLE
: | group="main" sCount=0 dsCount=0 obj=0x40a729a0 self=0x2a00bba8
: | sysTid=1813 nice=0 sched=0/0 cgrp=apps handle=1073849308
: | state=R schedstat=( 3245039730 1438341923 288 ) utm=275 stm=49 core=0
: at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method)
: at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:502)
: at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:355)
: at android.graphics.drawable.Drawable.createFromResourceStream(Drawable.java:785)
: at android.content.res.Resources.loadDrawable(Resources.java:1965)
: at android.content.res.Resources.getDrawable(Resources.java:660)
: at android.graphics.drawable.AnimationDrawable.inflate(AnimationDrawable.java:282)
: at android.graphics.drawable.Drawable.createFromXmlInner(Drawable.java:885)
: at android.graphics.drawable.Drawable.createFromXml(Drawable.java:822)
: at android.content.res.Resources.loadDrawable(Resources.java:1950)
: at android.content.res.Resources.getDrawable(Resources.java:660)
: at android.view.View.setBackgroundResource(View.java:14468)
: at com.example.appthree.MainActivity.onCreate(MainActivity.java:15)
: at android.app.Activity.performCreate(Activity.java:5104)
: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
: at android.app.ActivityThread.access$600(ActivityThread.java:141)
: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
: at android.os.Handler.dispatchMessage(Handler.java:99)
: at android.os.Looper.loop(Looper.java:137)
: at android.app.ActivityThread.main(ActivityThread.java:5041)
: at java.lang.reflect.Method.invokeNative(Native Method)
: at java.lang.reflect.Method.invoke(Method.java:511)
: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
: at dalvik.system.NativeStart.main(Native Method)
: --- decoder->decode returned false
: Shutting down VM
: threadid=1: thread exiting with uncaught exception (group=0x40a71930)
: FATAL EXCEPTION: main
: java.lang.OutOfMemoryError
: at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method)
: at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:502)
: at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:355)
: at android.graphics.drawable.Drawable.createFromResourceStream(Drawable.java:785)
: at android.content.res.Resources.loadDrawable(Resources.java:1965)
: at android.content.res.Resources.getDrawable(Resources.java:660)
: at android.graphics.drawable.AnimationDrawable.inflate(AnimationDrawable.java:282)
: at android.graphics.drawable.Drawable.createFromXmlInner(Drawable.java:885)
: at android.graphics.drawable.Drawable.createFromXml(Drawable.java:822)
: at android.content.res.Resources.loadDrawable(Resources.java:1950)
: at android.content.res.Resources.getDrawable(Resources.java:660)
: at android.view.View.setBackgroundResource(View.java:14468)
: at com.example.appthree.MainActivity.onCreate(MainActivity.java:15)
: at android.app.Activity.performCreate(Activity.java:5104)
: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
: at android.app.ActivityThread.access$600(ActivityThread.java:141)
: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
: at android.os.Handler.dispatchMessage(Handler.java:99)
: at android.os.Looper.loop(Looper.java:137)
: at android.app.ActivityThread.main(ActivityThread.java:5041)
: at java.lang.reflect.Method.invokeNative(Native Method)
: at java.lang.reflect.Method.invoke(Method.java:511)
: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
: at dalvik.system.NativeStart.main(Native Method)
: GC_CONCURRENT freed 30038K, 93% free 2539K/32768K, paused 73ms+97ms, total 472ms
正如马丁所说，Android不支持GIF。作为一种解决方法，Android提供Animation List/AnimationDrawable。您需要将GIF转换为单独的帧[.png文件]。我使用GIMP进行转换
这个GIF可以分解为它的框架：
将它们保存为frame01.png，frame02.png等，然后创建动画列表XML文件，例如progress_animation.xml
<animation-list android:id="@+id/selected" android:oneshot="false">
<item android:drawable="@drawable/frame01" android:duration="50" />
<item android:drawable="@drawable/frame02" android:duration="50" />
<item android:drawable="@drawable/frame03" android:duration="50" />
....
<item android:drawable="@drawable/frameN" android:duration="50" />
要开始动画，您需要将图像转换为AnimationDrawable，并在其上调用start（）
AnimationDrawable progressAnimation = (AnimationDrawable) yourImageView.getBackground();
progressAnimation.start();
当GIF动画作为电影播放时，Android支持gif动画。
把你的gif图像放在app \ src \ main \ assets中
像一个班级
public class MyGifView extends View {
Movie movie;
InputStream is;
long startTime;
public MyGifView(Context context) {
super(context);
try {
is = getResources().getAssets().open("anim.gif");
movie = Movie.decodeStream(is);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
super.onDraw(canvas);
long now = System.currentTimeMillis();
if (startTime == 0) // first time
startTime = now;
int relTime = (int) ((now - startTime) % movie.duration());
movie.setTime(relTime);
float scalefactorx = (float) this.getWidth() / (float) movie.width();
float scalefactory = (float) this.getHeight() / (float) movie.height();
canvas.scale(scalefactorx,1);
movie.draw(canvas, scalefactorx, scalefactory);
this.invalidate();
}
}
在xml activity_layout（backgroundFrameLayout）中的某处添加布局。在您的活动onCreate（）中使用：
FrameLayout frameLayout = findViewById(R.id.backgroundFrameLayout);
frameLayout.addView(new MyGifView(this));