Android之ViewFlipper实现手动+自动切换图片(附加动画效果)
分类:
IT文章
•
2022-05-28 08:47:41
ViewFlipper组件可以让你在activity中的一块区域实现自动动画效果切换图片的效果，若要手势切换，还需要GestureDetector的支持
首先写出布局文件，这里就简单的只添加一个ViewFlipper：
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<LinearLayout 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:orientation="vertical"
tools:context=".MainActivity" >
<!-- 为了使动画效果比较流畅这里还通过persistentDrawingCache设置了控件的绘制缓存策略，
一共有4中策略：
PERSISTENT_NO_CACHE 说明不在内存中保存绘图缓存；
PERSISTENT_ANIMATION_CACHE 说明只保存动画绘图缓存；
PERSISTENT_SCROLLING_CACHE 说明只保存滚动效果绘图缓存
PERSISTENT_ALL_CACHES 说明所有的绘图缓存都应该保存在内存中。 -->
<ViewFlipper
android:id="@+id/viewFlipper"
android:layout_width="match_parent"
android:layout_height="180dp"
android:inAnimation="@anim/anim_in_left"
android:outAnimation="@anim/anim_out_left"
android:persistentDrawingCache="animation"
/>
</LinearLayout>
View Code
然后写出几个定义动画的xml文件，这里只给出一个例子：
![]()
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="@android:anim/decelerate_interpolator">
<translate
android:duration="500"
android:fromXDelta="100%"
android:fromYDelta="0"
android:toXDelta="0"
android:toYDelta="0"
/>
<!-- <alpha
android:duration="500"
android:fromAlpha="0.0"
android:toAlpha="1.0"
/> -->
</set>
View Code
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import android.os.Bundle;
import android.app.Activity;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.ViewFlipper;
public class MainActivity extends Activity implements OnTouchListener {
private ViewFlipper flipper = null;
private GestureDetector gestureDetector = null;
private int[] images = new int[] {R.drawable.pic_about_banner01, R.drawable.pic_about_banner02, R.drawable.pic_about_banner03};
private static final int FLING_MIN_DISTANCE = 80;
private static final int FLING_MIN_VELOCITY = 150;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
flipper = (ViewFlipper) findViewById(R.id.viewFlipper);
// 将所有待显示图片填充入ViewFlipper
for (int i = 0; i < images.length; i++) {
ImageView view = new ImageView(this);
view.setBackgroundResource(images[i]);
flipper.addView(view);
}
// 开启自动启动并设置时间间隔
flipper.setAutoStart(true);
flipper.setFlipInterval(4000);
// 生成手势识别类实例
gestureDetector = new GestureDetector(this, new GerstureListener());
// 给ViewFlipper设置一个TouchListener
flipper.setOnTouchListener(this);
// 允许长按ViewFlipper
flipper.setLongClickable(true);
}
public boolean onTouch(View v, MotionEvent event) {
// 将触屏事件交给手势识别类处理
return gestureDetector.onTouchEvent(event);
}
private class GerstureListener implements OnGestureListener {
public boolean onDown(MotionEvent e) {
return false;
}
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
if (e1.getX() - e2.getX() > FLING_MIN_DISTANCE
&& Math.abs(velocityX) > FLING_MIN_VELOCITY) {
// 左滑时,按照规定动画切换
flipper.setInAnimation(MainActivity.this, R.anim.anim_in_left);
flipper.setOutAnimation(MainActivity.this, R.anim.anim_out_left);
flipper.showNext();
} else if (e2.getX() - e1.getX() > FLING_MIN_DISTANCE
&& Math.abs(velocityX) > FLING_MIN_VELOCITY) {
// 右滑时,按照规定动画切换
flipper.setInAnimation(MainActivity.this, R.anim.anim_in_right);
flipper.setOutAnimation(MainActivity.this, R.anim.anim_out_right);
flipper.showPrevious();
}
// 滑动动作完毕后,设置回右进左出的动画
flipper.setInAnimation(MainActivity.this, R.anim.anim_in_left);
flipper.setOutAnimation(MainActivity.this, R.anim.anim_out_left);
return false;
}
@Override
public void onLongPress(MotionEvent e) {
// TODO Auto-generated method stub
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
// TODO Auto-generated method stub
return false;
}
@Override
public void onShowPress(MotionEvent e) {
// TODO Auto-generated method stub
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
}
}
