android之帧动画实现

今天实现了一个帧动画的例子，

首先在res/anim下建立一个frame.xml来存放帧动画

<?xml version="1.0" encoding="utf-8"?> <animation-list xmlns:android="http://schemas.android.com/apk/res/android" android:oneshot="false"> <item android:drawable="@drawable/girl_1" android:duration="100"/> <item android:drawable="@drawable/girl_2" android:duration="100"/> <item android:drawable="@drawable/girl_3" android:duration="100"/> <item android:drawable="@drawable/girl_4" android:duration="100"/> <item android:drawable="@drawable/girl_5" android:duration="100"/> <item android:drawable="@drawable/girl_6" android:duration="100"/> <item android:drawable="@drawable/girl_7" android:duration="100"/> <item android:drawable="@drawable/girl_8" android:duration="100"/> <item android:drawable="@drawable/girl_9" android:duration="100"/> <item android:drawable="@drawable/girl_10" android:duration="100"/> <item android:drawable="@drawable/girl_11" android:duration="100"/> </animation-list>
引用的是drawable下面的图片，duration是设置时间是100毫秒

看下main.xml的布局

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" /> <LinearLayout android:id="@+id/linearLayout1" android:layout_width="match_parent" android:layout_height="wrap_content" > <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="播放动画" /> <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="停止动画" /> </LinearLayout> <RadioGroup android:id="@+id/radioGroup1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" > <RadioButton android:id="@+id/radioButton1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:checked="true" android:text="单次播放" /> <RadioButton android:id="@+id/radioButton2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="循环播放" /> </RadioGroup> <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="拖动进度条修改透明度(0 - 255)之间" /> <SeekBar android:id="@+id/seekBar1" android:layout_width="match_parent" android:layout_height="wrap_content" /> <ImageView android:id="@+id/imageView1" android:layout_width="200dip" android:layout_height="200dip" android:background="@anim/frame" /> </LinearLayout>

下面是控制帧动画的主要代码：

public class FrameDemoActivity extends Activity { /** Called when the activity is first created. */ private Button button1,button2; private RadioGroup radioGroup; private RadioButton radioButton1,radioButton2; private SeekBar seekBar; private ImageView imageView1; private AnimationDrawable animationDrawable; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); button1=(Button) this.findViewById(R.id.button1); button2=(Button) this.findViewById(R.id.button2); radioGroup=(RadioGroup) this.findViewById(R.id.radioGroup1); radioButton1=(RadioButton) this.findViewById(R.id.radioButton1); radioButton2=(RadioButton) this.findViewById(R.id.radioButton2); seekBar=(SeekBar) this.findViewById(R.id.seekBar1); imageView1=(ImageView) this.findViewById(R.id.imageView1); //通过ImageView对象拿到背景显示的AnimationDrawable animationDrawable=(AnimationDrawable) imageView1.getBackground(); button1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub if(!animationDrawable.isRunning()){ animationDrawable.start(); } } }); button2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub if(animationDrawable.isRunning()){ animationDrawable.stop(); } } }); radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() { @Override public void onCheckedChanged(RadioGroup group, int checkedId) { // TODO Auto-generated method stub if(checkedId==radioButton1.getId()){ //设置单次播放 animationDrawable.setOneShot(true); }else if(checkedId==radioButton2.getId()){ //设置循环播放 animationDrawable.setOneShot(false); } //设置播放后重新启动 animationDrawable.stop(); animationDrawable.start(); } }); //监听的进度条修改透明度 seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() { @Override public void onStopTrackingTouch(SeekBar seekBar) { // TODO Auto-generated method stub } @Override public void onStartTrackingTouch(SeekBar seekBar) { // TODO Auto-generated method stub } @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { // TODO Auto-generated method stub //设置动画Alpha值 animationDrawable.setAlpha(progress); //通知imageView 刷新屏幕 imageView1.postInvalidate(); } }); } }

运行效果如图所示：

进度条seekbar是设置透明度的。