1.学习此文章之前请先学习
Android高级图片滚动控件，编写3D版的图片轮播器_guolin的博客-CSDN博客_android 轮播图3d
本文主要是介绍如何实现动态的轮播图，主要是基于上一篇文章的获取网络图片，从而实现动态的轮播图。传统轮播图是使用本地固定的几张图片进行轮播，现在实现的是从网络上获取图片进行3D轮播展示效果。
实现了三种触发获取图片的事件，一种是点击按钮进行更新图片，一种是进行向左滑动获取图片，一种是按键获取图片。
2.项目结构
项目结构比较简单，一个mainactivity和两个文件进行辅助，还有一个xml文件进行布局。
3.activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffaa3f" >
<com.qiri.myapplication.Image3DSwitchView
android:id="@+id/image_switch_view"
android:layout_width="match_parent"
android:layout_height="300dp"
android:layout_marginTop="100dp">
<com.qiri.myapplication.Image3DView
android:id="@+id/image1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@drawable/t1" />
<com.qiri.myapplication.Image3DView
android:id="@+id/image2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@drawable/t2" />
<com.qiri.myapplication.Image3DView
android:id="@+id/image3"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@drawable/t3" />
<com.qiri.myapplication.Image3DView
android:id="@+id/image4"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@drawable/t4" />
<com.qiri.myapplication.Image3DView
android:id="@+id/image5"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@drawable/t5" />
<com.qiri.myapplication.Image3DView
android:id="@+id/image6"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@drawable/t1" />
<com.qiri.myapplication.Image3DView
android:id="@+id/image7"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@drawable/t2" />
</com.qiri.myapplication.Image3DSwitchView>
<Button
android:id="@+id/btn"
android:text="1/7"
android:textSize="32dp"
android:textColor="#ffffff"
android:layout_below="@+id/image_switch_view"
android:background="#fadd44"
android:layout_width="200dp"
android:layout_height="100dp"
android:layout_marginLeft="350dp"/>
<Button
android:layout_width="200dp"
android:layout_height="100dp"
android:id="@+id/btn2"
android:hint="点击更换图片"
android:background="@color/fastlane_background"
android:layout_below="@+id/image_switch_view"
android:layout_marginLeft="620dp"
/>
</RelativeLayout>效果
这里主要是设置了七个图片，还有一个索引展示是第几张图片，还有一个点击按钮。
在drawable中存放了最开始的几张图片，这样程序刚运行的时候会进行加载。
4.colors.xml
<resources>
<color name="background_gradient_start">#000000</color>
<color name="background_gradient_end">#DDDDDD</color>
<color name="fastlane_background">#0096a6</color>
<color name="search_opaque">#ffaa3f</color>
<color name="selected_background">#ffaa3f</color>
<color name="default_background">#3d3d3d</color>
</resources>
这个文件是放一些颜色布局，没有可能会报错，但是很好解决。
5.Image3DView
public class Image3DView extends ImageView {
/**
* 旋转角度的基准值
*/
private static final float BASE_DEGREE = 50f;
/**
* 旋转深度的基准值
*/
private static final float BASE_DEEP = 150f;
private Camera mCamera;
private Matrix mMaxtrix;
private Bitmap mBitmap;
/**
* 当前图片对应的下标
*/
private int mIndex;
/**
* 在前图片在X轴方向滚动的距离
*/
private int mScrollX;
/**
* Image3DSwitchView控件的宽度
*/
private int mLayoutWidth;
/**
* 当前图片的宽度
*/
private int mWidth;
/**
* 当前旋转的角度
*/
private float mRotateDegree;
/**
* 旋转的中心点
*/
private float mDx;
/**
* 旋转的深度
*/
private float mDeep;
public Image3DView(Context context, AttributeSet attrs) {
super(context, attrs);
mCamera = new Camera();
mMaxtrix = new Matrix();
//设置可获焦 & 可点击
setFocusable(true);
setClickable(true);
}
/**
* 初始化Image3DView所需要的信息，包括图片宽度，截取背景图等。
*/
public void initImageViewBitmap() {
if (mBitmap == null) {
//我们要获取cache首先要通过setDrawingCacheEnable方法开启cache，然后再调用getDrawingCache方法就可以获得view的cache图片了。
setDrawingCacheEnabled(true);
buildDrawingCache();
mBitmap = getDrawingCache();
}
mLayoutWidth = Image3DSwitchView.mWidth;
mWidth = getWidth() + Image3DSwitchView.IMAGE_PADDING * 2;
}
/**
* 设置旋转角度。
*
* @param index 当前图片的下标
* @param scrollX 当前图片在X轴方向滚动的距离
*/
public void setRotateData(int index, int scrollX) {
mIndex = index;
mScrollX = scrollX;
}
/**
* 回收当前的Bitmap对象，以释放内存。
*/
public void recycleBitmap() {
if (mBitmap != null && !mBitmap.isRecycled()) {
mBitmap.recycle();
}
}
@Override
public void setImageResource(int resId) {
super.setImageResource(resId);
mBitmap = null;
initImageViewBitmap();
}
@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
mBitmap = null;
initImageViewBitmap();
}
@Override
public void setImageDrawable(Drawable drawable) {
super.setImageDrawable(drawable);
mBitmap = null;
initImageViewBitmap();
}
@Override
public void setImageURI(Uri uri) {
super.setImageURI(uri);
//mBitmap = null;
initImageViewBitmap();
}
@Override
protected void onDraw(Canvas canvas) {
if (mBitmap == null) {
// 如果Bitmap对象还不存在，先使用父类的onDraw方法进行绘制
super.onDraw(canvas);
} else {
if (isImageVisible()) {
// 绘图时需要注意，只有当图片可见的时候才进行绘制，这样可以节省运算效率
computeRotateData();
mCamera.save();
mCamera.translate(0.0f, 0.0f, mDeep);
mCamera.rotateY(mRotateDegree);
mCamera.getMatrix(mMaxtrix);
mCamera.restore();
mMaxtrix.preTranslate(-mDx, -getHeight() / 2);
mMaxtrix.postTranslate(mDx, getHeight() / 2);
canvas.drawBitmap(mBitmap, mMaxtrix, null);
}
}
}
/**
* 在这里计算所有旋转所需要的数据。
*/
private void computeRotateData() {
float degreePerPix = BASE_DEGREE / mWidth;
float deepPerPix = BASE_DEEP / ((mLayoutWidth - mWidth) / 2);
switch (mIndex) {
case 0:
mDx = mWidth;
mRotateDegree = 360f - (2 * mWidth + mScrollX) * degreePerPix;
if (mScrollX < -mWidth) {
mDeep = 0;
} else {
mDeep = (mWidth + mScrollX) * deepPerPix;
}
break;
case 1:
if (mScrollX > 0) {
mDx = mWidth;
mRotateDegree = (360f - BASE_DEGREE) - mScrollX * degreePerPix;
mDeep = mScrollX * deepPerPix;
} else {
if (mScrollX < -mWidth) {
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = (-mScrollX - mWidth) * degreePerPix;
} else {
mDx = mWidth;
mRotateDegree = 360f - (mWidth + mScrollX) * degreePerPix;
}
mDeep = 0;
}
break;
case 2:
if (mScrollX > 0) {
mDx = mWidth;
mRotateDegree = 360f - mScrollX * degreePerPix;
mDeep = 0;
if (mScrollX > mWidth) {
mDeep = (mScrollX - mWidth) * deepPerPix;
}
} else {
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = -mScrollX * degreePerPix;
mDeep = 0;
if (mScrollX < -mWidth) {
mDeep = -(mWidth + mScrollX) * deepPerPix;
}
}
break;
case 3:
if (mScrollX < 0) {
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = BASE_DEGREE - mScrollX * degreePerPix;
mDeep = -mScrollX * deepPerPix;
} else {
if (mScrollX > mWidth) {
mDx = mWidth;
mRotateDegree = 360f - (mScrollX - mWidth) * degreePerPix;
} else {
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = BASE_DEGREE - mScrollX * degreePerPix;
}
mDeep = 0;
}
break;
case 4:
mDx = -Image3DSwitchView.IMAGE_PADDING * 2;
mRotateDegree = (2 * mWidth - mScrollX) * degreePerPix;
if (mScrollX > mWidth) {
mDeep = 0;
} else {
mDeep = (mWidth - mScrollX) * deepPerPix;
}
break;
}
}
/**
* 判断当前图片是否可见。
*
* @return 当前图片可见返回true，不可见返回false。
*/
private boolean isImageVisible() {
boolean isVisible = false;
switch (mIndex) {
case 0:
if (mScrollX < (mLayoutWidth - mWidth) / 2 - mWidth) {
isVisible = true;
} else {
isVisible = false;
}
break;
case 1:
if (mScrollX > (mLayoutWidth - mWidth) / 2) {
isVisible = false;
} else {
isVisible = true;
}
break;
case 2:
if (mScrollX > mLayoutWidth / 2 + mWidth / 2
|| mScrollX < -mLayoutWidth / 2 - mWidth / 2) {
isVisible = false;
} else {
isVisible = true;
}
break;
case 3:
if (mScrollX < -(mLayoutWidth - mWidth) / 2) {
isVisible = false;
} else {
isVisible = true;
}
break;
case 4:
if (mScrollX > mWidth - (mLayoutWidth - mWidth) / 2) {
isVisible = true;
} else {
isVisible = false;
}
break;
}
return isVisible;
}
}6.Image3DSwitchView
public class Image3DSwitchView extends LinearLayout {
private int currentPage =0;//定义当前第几页
/**
* 图片左右两边的空白间距
*/
public static final int IMAGE_PADDING = 5;
private static final int TOUCH_STATE_REST = 0;
private static final int TOUCH_STATE_SCROLLING = 1;
/**
* 滚动到下一张图片的速度
*/
private static final int SNAP_VELOCITY = 600;
/**
* 表示滚动到下一张图片这个动作
*/
private static final int SCROLL_NEXT = 0;
/**
* 表示滚动到上一张图片这个动作
*/
private static final int SCROLL_PREVIOUS = 1;
/**
* 表示滚动回原图片这个动作
*/
private static final int SCROLL_BACK = 2;
private static Handler handler = new Handler();
/**
* 控件宽度
*/
public static int mWidth;
private VelocityTracker mVelocityTracker;//主要用跟踪触摸屏事件(flinging事件和其他gestures手势事件)的速率
private Scroller mScroller;
/**
* 图片滚动监听器，当图片发生滚动时回调这个接口
*/
private OnImageSwitchListener mListener;
/**
* 记录当前的触摸状态
*/
private int mTouchState = TOUCH_STATE_REST;
/**
* 记录被判定为滚动运动的最小滚动值
*/
private int mTouchSlop;
/**
* 记录控件高度
*/
private int mHeight;
/**
* 记录每张图片的宽度
*/
private int mImageWidth;
/**
* 记录图片的总数量
*/
private int mCount;
/**
* 记录当前显示图片的坐标
*/
private int mCurrentImage;
public int getmCurrentImage() {
return mCurrentImage;
}
public void setmCurrentImage(int mCurrentImage) {
this.mCurrentImage = mCurrentImage;
}
/**
* 记录上次触摸的横坐标值
*/
private float mLastMotionX;
/**
* 是否强制重新布局
*/
private boolean forceToRelayout;
private int[] mItems;
public Image3DSwitchView(Context context, AttributeSet attrs) {
super(context, attrs);
mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
mScroller = new Scroller(context);
//设置可以获得焦点
setFocusable(true);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed || forceToRelayout) {
mCount = getChildCount();
// 图片数量必须大于5，不然无法正常显示
if (mCount < 5) {
return;
}
mWidth = getMeasuredWidth();
mHeight = getMeasuredHeight();
// 每张图片的宽度设定为控件宽度的百分之六十
mImageWidth = (int) (mWidth * 0.6);
if (mCurrentImage >= 0 && mCurrentImage < mCount) {
mScroller.abortAnimation();
setScrollX(0);
int left = -mImageWidth * 2 + (mWidth - mImageWidth) / 2;
// 分别获取每个位置上应该显示的图片下标
int[] items = {getIndexForItem(1), getIndexForItem(2),
getIndexForItem(3), getIndexForItem(4),
getIndexForItem(5)};
mItems = items;
// 通过循环为每张图片设定位置
for (int i = 0; i < items.length; i++) {
Image3DView childView = (Image3DView) getChildAt(items[i]);
childView.layout(left + IMAGE_PADDING, 0, left
+ mImageWidth - IMAGE_PADDING, mHeight);
childView.initImageViewBitmap();
left = left + mImageWidth;
}
refreshImageShowing();
}
forceToRelayout = false;
}
}
public interface OnFocusListener{
void changeImage();
void onFocus();
void setValue(String value);
}
private OnFocusListener onFocusListener;
public void setonFocusListener(OnFocusListener onFocusListener){
this.onFocusListener = onFocusListener;
}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
onFocusListener.changeImage();
if (event.getAction() == KeyEvent.ACTION_DOWN){
switch (event.getKeyCode()){
//按下键 响应回调
case KeyEvent.KEYCODE_DPAD_DOWN:
if (onFocusListener != null){onFocusListener.onFocus();}
break;
//按确定键
case KeyEvent.KEYCODE_DPAD_CENTER:
Toast.makeText(getContext(),"点击了图片"+(currentPage%7+1),Toast.LENGTH_SHORT).show();
break;
//右键
case KeyEvent.KEYCODE_DPAD_RIGHT:
scrollToNext();
if (onFocusListener !=null){
onFocusListener.setValue((currentPage%7+1)+"");
}
break;
//左键
case KeyEvent.KEYCODE_DPAD_LEFT:
scrollToPrevious();
if (onFocusListener !=null){
onFocusListener.setValue((currentPage%7+1)+"");
}
break;
}
}
return true;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (mScroller.isFinished()) {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
int action = event.getAction();
float x = event.getX();
switch (action) {
case MotionEvent.ACTION_DOWN:
// 记录按下时的横坐标
mLastMotionX = x;
break;
case MotionEvent.ACTION_MOVE:
int disX = (int) (mLastMotionX - x);
mLastMotionX = x;
scrollBy(disX, 0);
// 当发生移动时刷新图片的显示状态
refreshImageShowing();
break;
case MotionEvent.ACTION_UP:
mVelocityTracker.computeCurrentVelocity(1000);
int velocityX = (int) mVelocityTracker.getXVelocity();
if (shouldScrollToNext(velocityX)) {
// 滚动到下一张图
onFocusListener.changeImage();
onFocusListener.setValue(String.valueOf(mCurrentImage));
scrollToNext();
} else if (shouldScrollToPrevious(velocityX)) {
// 滚动到上一张图
onFocusListener.setValue(String.valueOf(mCurrentImage));
scrollToPrevious();
} else {
// 滚动回当前图片
scrollBack();
}
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
break;
}
}
return true;
}
/**
* 根据当前的触摸状态来决定是否屏蔽子控件的交互能力。
*/
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE)
&& (mTouchState != TOUCH_STATE_REST)) {
return true;
}
float x = ev.getX();
switch (action) {
case MotionEvent.ACTION_DOWN:
mLastMotionX = x;
mTouchState = TOUCH_STATE_REST;
break;
case MotionEvent.ACTION_MOVE:
int xDiff = (int) Math.abs(mLastMotionX - x);
if (xDiff > mTouchSlop) {
mTouchState = TOUCH_STATE_SCROLLING;
}
break;
case MotionEvent.ACTION_UP:
default:
mTouchState = TOUCH_STATE_REST;
break;
}
return mTouchState != TOUCH_STATE_REST;
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
refreshImageShowing();
postInvalidate();
}
}
/**
* 设置图片滚动的监听器，每当有图片滚动时会回调此接口。
*
* @param listener 图片滚动监听器
*/
public void setOnImageSwitchListener(OnImageSwitchListener listener) {
mListener = listener;
}
/**
* 设置当前显示图片的下标，注意如果该值小于零或大于等于图片的总数量，图片则无法正常显示。
*
* @param currentImage 图片的下标
*/
public void setCurrentImage(int currentImage) {
mCurrentImage = currentImage;
requestLayout();
}
/**
* 滚动到下一张图片。
*/
public void scrollToNext() {
if (mScroller.isFinished()) {
currentPage++;
int disX = mImageWidth - getScrollX();
checkImageSwitchBorder(SCROLL_NEXT);
if (mListener != null) {
mListener.onImageSwitch(mCurrentImage);
}
beginScroll(getScrollX(), 0, disX, 0, SCROLL_NEXT);
}
}
/**
* 滚动到上一张图片。
*/
public void scrollToPrevious() {
if (mScroller.isFinished()) {
if (currentPage ==0){
currentPage = 7;
}else
currentPage--;
int disX = -mImageWidth - getScrollX();
checkImageSwitchBorder(SCROLL_PREVIOUS);
if (mListener != null) {
mListener.onImageSwitch(mCurrentImage);
}
beginScroll(getScrollX(), 0, disX, 0, SCROLL_PREVIOUS);
}
}
/**
* 滚动回原图片。
*/
public void scrollBack() {
if (mScroller.isFinished()) {
beginScroll(getScrollX(), 0, -getScrollX(), 0, SCROLL_BACK);
}
}
/**
* 回收所有图片对象，释放内存。
*/
public void clear() {
for (int i = 0; i < mCount; i++) {
Image3DView childView = (Image3DView) getChildAt(i);
childView.recycleBitmap();
}
}
/**
* 让控件中的所有图片开始滚动。
*/
private void beginScroll(int startX, int startY, int dx, int dy,
final int action) {
int duration = (int) (700f / mImageWidth * Math.abs(dx));
mScroller.startScroll(startX, startY, dx, dy, duration);
invalidate();
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (action == SCROLL_NEXT || action == SCROLL_PREVIOUS) {
forceToRelayout = true;
requestLayout();
}
}
}, duration);
}
/**
* 根据当前图片的下标和传入的item参数，来判断item位置上应该显示哪张图片。
*
* @param item 取值范围是1-5
* @return 对应item位置上应该显示哪张图片。
*/
private int getIndexForItem(int item) {
int index = -1;
index = mCurrentImage + item - 3;
while (index < 0) {
index = index + mCount;
}
while (index > mCount - 1) {
index = index - mCount;
}
return index;
}
/**
* 刷新所有图片的显示状态，包括当前的旋转角度。
*/
private void refreshImageShowing() {
for (int i = 0; i < mItems.length; i++) {
Image3DView childView = (Image3DView) getChildAt(mItems[i]);
childView.setRotateData(i, getScrollX());
childView.invalidate();
}
}
/**
* 检查图片的边界，防止图片的下标超出规定范围。
*/
private void checkImageSwitchBorder(int action) {
if (action == SCROLL_NEXT && ++mCurrentImage >= mCount) {
mCurrentImage = 0;
} else if (action == SCROLL_PREVIOUS && --mCurrentImage < 0) {
mCurrentImage = mCount - 1;
}
}
/**
* 判断是否应该滚动到下一张图片。
*/
private boolean shouldScrollToNext(int velocityX) {
return velocityX < -SNAP_VELOCITY || getScrollX() > mImageWidth / 2;
}
/**
* 判断是否应该滚动到上一张图片。
*/
private boolean shouldScrollToPrevious(int velocityX) {
return velocityX > SNAP_VELOCITY || getScrollX() < -mImageWidth / 2;
}
/**
* 图片滚动的监听器
*/
public interface OnImageSwitchListener {
/**
* 当图片滚动时会回调此方法
*
* @param currentImage 当前图片的坐标
*/
void onImageSwitch(int currentImage);
}
}7.MainActivity
public class MainActivity extends Activity {
private static final String TAG="MainActivity";
private Button btn;
private Button btn2;
private Image3DSwitchView image3DSwitchView;
private Image3DView image3DView1,image3DView2,image3DView3,
image3DView4,image3DView5,image3DView6,image3DView7;
String url = "https://api.ixiaowai.cn/gqapi/gqapi.php";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn = (Button) findViewById(R.id.btn);
btn2 = (Button) findViewById(R.id.btn2);
image3DSwitchView = (Image3DSwitchView) findViewById(R.id.image_switch_view);
image3DView1=(Image3DView)findViewById(R.id.image1);
image3DView2=(Image3DView)findViewById(R.id.image2);
image3DView3=(Image3DView)findViewById(R.id.image3);
image3DView4=(Image3DView)findViewById(R.id.image4);
image3DView5=(Image3DView)findViewById(R.id.image5);
image3DView6=(Image3DView)findViewById(R.id.image6);
image3DView7=(Image3DView)findViewById(R.id.image7);
btn2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new Thread(new Runnable() {
@Override
public void run() {
Bitmap bmp = getURLimage(url);
Message msg = new Message();
msg.what = 0;
msg.obj = bmp;
handle.sendMessage(msg);
}
}).start();
}
});
btn.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DPAD_UP && event.getAction()== KeyEvent.ACTION_DOWN)
image3DSwitchView.requestFocus();
return true;
}
});
//设置监听，并实现接口
image3DSwitchView.setonFocusListener(new Image3DSwitchView.OnFocusListener() {
@Override
public void changeImage() {
new Thread(new Runnable() {
@Override
public void run() {
Bitmap bmp = getURLimage(url);
Message msg = new Message();
msg.what = 0;
msg.obj = bmp;
handle.sendMessage(msg);
}
}).start();
}
@Override
public void onFocus() {
btn.requestFocus();
}
@Override
public void setValue(String value) {
btn.setText(value+"/7");
}
});
}
//在消息队列中实现对控件的更改
private Handler handle = new Handler() {
public void handleMessage(Message msg) {
switch (msg.what) {
case 0:
Bitmap bmp=(Bitmap)msg.obj;
int i=image3DSwitchView.getmCurrentImage();
Image3DView image3DView=(Image3DView) image3DSwitchView.getChildAt(i);
Log.d(TAG, "handleMessage: "+image3DView);
image3DView.setImageBitmap(bmp);
break;
}
};
};
//加载图片
public Bitmap getURLimage(String url) {
Bitmap bmp = null;
try {
URL myurl = new URL(url);
// 获得连接
HttpURLConnection conn = (HttpURLConnection) myurl.openConnection();
conn.setConnectTimeout(6000);//设置超时
conn.setDoInput(true);
conn.setUseCaches(false);//不缓存
conn.connect();
InputStream is = conn.getInputStream();//获得图片的数据流
bmp = BitmapFactory.decodeStream(is);//读取图像数据
is.close();
} catch (Exception e) {
e.printStackTrace();
}
return bmp;
}
}
8.效果展示
进行向左滑动的时候，会刷新一张图片，实现轮播图效果，点击更换图片会让当前中间的图片进行更换。
