ViewFlipper 和 ViewPager 的区别
ViewFlipper继承ViewAnimator，切换view的时候是有动画效果的，适合做ppt，多界面的程序欢迎引导界面，算是个轻量级的组件，适合展示静态数据，少量数据。ViewPager继承ViewGroup。看官网描述，这货和Fragment是好搭档，Fragment有自己的生命周期。也就是说ViewPager更适用复杂的视图切换，而且Viewpager有自己的adapter，这也让其适应复杂对象，实现数据的动态加载。
1、ViewFlipper1）View切换的控件—ViewFlipper介绍ViewFilpper类继承于ViewAnimator类。而ViewAnimator类继承于FrameLayout。查看ViewAnimator类的源码可以看出此类的作用主要是为其中的View切换提供动画效果。该类有如下几个和动画相关的方法。setInAnimation：设置View进入屏幕时候使用的动画。该方法有两个重载方法，即可以直接传入Animation对象，也可以传入定义的Animation文件的resourceID。setOutAnimation：设置View退出屏幕时候使用的动画。使用方法和setInAnimation方法一样。showNext：调用该方法可以显示FrameLayout里面的下一个View。showPrevious：调用该方法可以来显示FrameLayout里面的上一个View。查看ViewFlipper的源码可以看到，ViewFlipper主要用来实现View的自动切换。该类提供了如下几个主要的方法。setFilpInterval：设置View切换的时间间隔。参数为毫秒。startFlipping：开始进行View的切换，时间间隔是上述方法设置的间隔数。切换会循环进行。stopFlipping：停止View切换。setAutoStart：设置是否自动开始。如果设置为“true”，当ViewFlipper显示的时候View的切换会自动开始。一般情况下，我们都会使用ViewFilpper类实现View的切换，而不使用它的父类ViewAnimator类。2）实现滑动—GestureDetector介绍如果想要实现滑动翻页的效果，就要了解另外一个类：Android.view.GestureDetector类。GestureDetector类中可以用来检测各种手势事件。该类有两个回调接口，分别用来通知具体的事件。GestureDetector.OnDoubleTapListener：用来通知DoubleTap事件，类似于PC上面的鼠标的双击事件。GestureDetector.OnGestureListener：用来通知普通的手势事件，该接口有六个回调方法，具体的可以查看API。这里想要实现滑动的判断，就需要用到其中的onFling()方法。3）具体的实现下面的代码片段详细说明了如何实现滑动翻页。
<?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" >
<ViewFlipper
android:id="@+id/viewFlipper1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ImageView
android:id="@+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/b" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/c" />
<ImageView
android:id="@+id/imageView3"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/d" />
<ImageView
android:id="@+id/imageView4"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/f" />
<ImageView
android:id="@+id/imageView5"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/g" />
</ViewFlipper>
</LinearLayout>
public class ViewFlipperActivity extends Activity implements OnTouchListener, android.view.GestureDetector.OnGestureListener {
private ViewFlipper flipper;
GestureDetector mGestureDetector;
private int mCurrentLayoutState;
private static final int FLING_MIN_DISTANCE = 80;
private static final int FLING_MIN_VELOCITY = 150;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.viewflipper);
flipper=(ViewFlipper) this.findViewById(R.id.viewFlipper1);
//注册一个用于手势识别的类
mGestureDetector = new GestureDetector(this);
//给mFlipper设置一个listener
flipper.setOnTouchListener(this);
mCurrentLayoutState = 0;
//允许长按住ViewFlipper,这样才能识别拖动等手势
flipper.setLongClickable(true);
}
/**
* 此方法在本例中未用到，可以指定跳转到某个页面
* @param switchTo
*/
public void switchLayoutStateTo(int switchTo) {
while (mCurrentLayoutState != switchTo) {
if (mCurrentLayoutState > switchTo) {
mCurrentLayoutState--;
flipper.setInAnimation(inFromLeftAnimation());
flipper.setOutAnimation(outToRightAnimation());
flipper.showPrevious();
} else {
mCurrentLayoutState++;
flipper.setInAnimation(inFromRightAnimation());
flipper.setOutAnimation(outToLeftAnimation());
flipper.showNext();
}
}
}
/**
* 定义从右侧进入的动画效果
* @return
*/
protected Animation inFromRightAnimation() {
Animation inFromRight = new TranslateAnimation(
Animation.RELATIVE_TO_PARENT, +1.0f,
Animation.RELATIVE_TO_PARENT, 0.0f,
Animation.RELATIVE_TO_PARENT, 0.0f,
Animation.RELATIVE_TO_PARENT, 0.0f);
inFromRight.setDuration(200);
inFromRight.setInterpolator(new AccelerateInterpolator());
return inFromRight;
}
/**
* 定义从左侧退出的动画效果
* @return
*/
protected Animation outToLeftAnimation() {
Animation outtoLeft = new TranslateAnimation(
Animation.RELATIVE_TO_PARENT, 0.0f,
Animation.RELATIVE_TO_PARENT, -1.0f,
Animation.RELATIVE_TO_PARENT, 0.0f,
Animation.RELATIVE_TO_PARENT, 0.0f);
outtoLeft.setDuration(200);
outtoLeft.setInterpolator(new AccelerateInterpolator());
return outtoLeft;
}
/**
* 定义从左侧进入的动画效果
* @return
*/
protected Animation inFromLeftAnimation() {
Animation inFromLeft = new TranslateAnimation(
Animation.RELATIVE_TO_PARENT, -1.0f,
Animation.RELATIVE_TO_PARENT, 0.0f,
Animation.RELATIVE_TO_PARENT, 0.0f,
Animation.RELATIVE_TO_PARENT, 0.0f);
inFromLeft.setDuration(200);
inFromLeft.setInterpolator(new AccelerateInterpolator());
return inFromLeft;
}
/**
* 定义从右侧退出时的动画效果
* @return
*/
protected Animation outToRightAnimation() {
Animation outtoRight = new TranslateAnimation(
Animation.RELATIVE_TO_PARENT, 0.0f,
Animation.RELATIVE_TO_PARENT, +1.0f,
Animation.RELATIVE_TO_PARENT, 0.0f,
Animation.RELATIVE_TO_PARENT, 0.0f);
outtoRight.setDuration(200);
outtoRight.setInterpolator(new AccelerateInterpolator());
return outtoRight;
}
public boolean onDown(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
/*
* 用户按下触摸屏、快速移动后松开即触发这个事件
* e1：第1个ACTION_DOWN MotionEvent
* e2：最后一个ACTION_MOVE MotionEvent
* velocityX：X轴上的移动速度，像素/秒
* velocityY：Y轴上的移动速度，像素/秒
* 触发条件 ：
* X轴的坐标位移大于FLING_MIN_DISTANCE，且移动速度大于FLING_MIN_VELOCITY个像素/秒
*/
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) {
// 当像左侧滑动的时候
//设置View进入屏幕时候使用的动画
flipper.setInAnimation(inFromRightAnimation());
//设置View退出屏幕时候使用的动画
flipper.setOutAnimation(outToLeftAnimation());
flipper.showNext();
} else if (e2.getX() - e1.getX() > FLING_MIN_DISTANCE
&& Math.abs(velocityX) > FLING_MIN_VELOCITY) {
// 当像右侧滑动的时候
flipper.setInAnimation(inFromLeftAnimation());
flipper.setOutAnimation(outToRightAnimation());
flipper.showPrevious();
}
return false;
}
public void onLongPress(MotionEvent e) {
// TODO Auto-generated method stub
}
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
float distanceY) {
// TODO Auto-generated method stub
return false;
}
public void onShowPress(MotionEvent e) {
// TODO Auto-generated method stub
}
public boolean onSingleTapUp(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
// 一定要将触屏事件交给手势识别类去处理（自己处理会很麻烦的）
return mGestureDetector.onTouchEvent(event);
}
}
2、ViewPager说明：ViewPager用于实现多页面的切换效果，该类存在于Google的兼容包里面，所以在引用时记得在BuilldPath中加入“android-support-v4.jar”主布局文件main.xml
<?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" >
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" >
<android.support.v4.view.PagerTitleStrip
android:id="@+id/pagertitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top" />
</android.support.v4.view.ViewPager>
</LinearLayout>其中ViewPager为多页显示控件，PagerTitleStrip用于显示当前页面的标题主窗口代码：PagerTitleDemoActivity.java
package com.ns.pager;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.PagerTitleStrip;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
public class PagerTitleDemoActivity extends Activity {
/** Called when the activity is first created. */
private ViewPager mViewPager;
private PagerTitleStrip mPagerTitleStrip;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mViewPager = (ViewPager)findViewById(R.id.viewpager);
mPagerTitleStrip = (PagerTitleStrip)findViewById(R.id.pagertitle);
//将要分页显示的View装入数组中
LayoutInflater mLi = LayoutInflater.from(this);
View view1 = mLi.inflate(R.layout.view1, null);
View view2 = mLi.inflate(R.layout.view2, null);
View view3 = mLi.inflate(R.layout.view3, null);
//每个页面的Title数据
final ArrayList<View> views = new ArrayList<View>();
views.add(view1);
views.add(view2);
views.add(view3);
final ArrayList<String> titles = new ArrayList<String>();
titles.add("tab1");
titles.add("tab2");
titles.add("tab3");
//填充ViewPager的数据适配器
PagerAdapter mPagerAdapter = new PagerAdapter() {
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
@Override
public int getCount() {
return views.size();
}
@Override
public void destroyItem(View container, int position, Object object) {
((ViewPager)container).removeView(views.get(position));
}
@Override
public CharSequence getPageTitle(int position) {
return titles.get(position);
}
@Override
public Object instantiateItem(View container, int position) {
((ViewPager)container).addView(views.get(position));
return views.get(position);
}
};
mViewPager.setAdapter(mPagerAdapter);
}
}运行效果：
3、Gallerypackage xiaosi.gallery;
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.Toast;
public class GalleryActivity extends Activity {
/** Called when the activity is first created. */
private Gallery gallery =null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gallery = (Gallery)findViewById(R.id.gallery);
//设置图片适配器
gallery.setAdapter(new ImageAdapter(this));
gallery.setSpacing(5);
//设置监听器
gallery.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
Toast.makeText(GalleryActivity.this, "点击了第"+arg2+"张图片", Toast.LENGTH_LONG).show();
}
});
}
}
class ImageAdapter extends BaseAdapter{
int mGalleryItemBackground;
private Context context;
//图片源数组
private Integer[] imageInteger={
R.drawable.a,
R.drawable.b,
R.drawable.c,
R.drawable.d
};
public ImageAdapter(Context c){
context = c;
TypedArray attr = context.obtainStyledAttributes(R.styleable.HelloGallery);
mGalleryItemBackground = attr.getResourceId(R.styleable.HelloGallery_android_galleryItemBackground, 0);
attr.recycle();
}
// 获取图片的个数
public int getCount() {
return imageInteger.length;
}
// 获取图片在库中的位置
public Object getItem(int position) {
return position;
}
// 获取图片ID
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView = new ImageView(context);
// 给ImageView设置资源
imageView.setImageResource(imageInteger);
// 设置显示比例类型
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
// 设置布局 图片120*80
imageView.setLayoutParams(new Gallery.LayoutParams(180, 100));
imageView.setBackgroundResource(mGalleryItemBackground);
return imageView;
}
}
mian.xml
<?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" >
<Gallery
android:id="@+id/gallery"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="bottom"
android:background="?android:galleryItemBackground"/>
</LinearLayout>
创建一个新的XML文件在res/values/目录下 attrs.xml命名。
这是一个定制的styleable资源,可以应用于一个布局。
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="HelloGallery">
<attr name="android:galleryItemBackground" />
</declare-styleable>
</resources>
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