android水平循环滚动控件使用详解

本文实例为大家分享了android水平循环滚动控件的具体代码，供大家参考，具体内容如下

CycleScrollView.java

package com.example.test; 
 
import android.content.Context; 
import android.graphics.Rect; 
import android.os.Handler; 
import android.util.AttributeSet; 
import android.view.GestureDetector; 
import android.view.GestureDetector.OnGestureListener; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.Scroller; 
 
@SuppressWarnings("deprecation") 
public class CycleScrollView extends ViewGroup implements onGestureListener { 
 
 static final String TAG = "CycleScrollView"; 
 Context mContext; 
 
  
 public static final long SCROLL_VELOCITY = 50; 
 
  
 public static final int SCROLL_OFFSET = -1; 
 
  
 public static final long TOUCH_DELAYMILLIS = 2000; 
 
  
 public static final int FLING_DURATION = 2000; 
 
  
 public static final int MAX_VELOCITY_X = 1000; 
 
 private GestureDetector detector; 
 private Handler mHandler; 
 private Scroller mScroller; 
 
  
 private CycleScrollAdapter mAdapter; 
 private onItemClickListener mOnItemClickListener; 
 
  
 private int mPreIndex; 
 private int mCurrentIndex; 
 private int mNextIndex; 
 private View mCurrentView; 
 private View mPreView; 
 private View mNextView; 
 
 private float mLastMotionX; 
 
 // The reLayout is false can not invoke onLayout. 
 private boolean reLayout = false; 
 
 // If the item count more than screen that can scroll. 
 private boolean canScroll = false; 
 
 // A flag for switch current view. 
 private boolean mCurrentViewAtLeft = true; 
 
 // Fling distance. 
 private int mFlingX = 0; 
 
 private boolean isMoveAction = false; 
 
 private int defaultItemY = 10; 
   
 private int maxItemCount = 7; 
 
 private int initItemX = 20; 
 
  
 private int screenWidth; 
 
  
 private int itemHeight; 
 
  
 private int itemWidth; 
 
  
 private int itemX = getInitItemX(); 
 
  
 private int itemY = defaultItemY; 
 
 // Auto scroll view task. 
 private final Runnable mScrollTask = new Runnable() { 
 
  @Override 
  public void run() { 
   if (canScroll) { 
    scrollView(SCROLL_OFFSET); 
    mHandler.postDelayed(this, SCROLL_VELOCITY);// Loop self. 
   } 
  } 
 }; 
 
 public CycleScrollView(Context context) { 
  super(context); 
  onCreate(context); 
 } 
 
 public CycleScrollView(Context context, AttributeSet attrs) { 
  super(context, attrs); 
  onCreate(context); 
 } 
 
 public CycleScrollView(Context context, AttributeSet attrs, int defStyle) { 
  super(context, attrs, defStyle); 
  onCreate(context); 
 } 
 
 private void onCreate(Context context) { 
  mContext = context; 
  detector = new GestureDetector(this); 
  mHandler = new Handler(); 
  mScroller = new Scroller(context); 
 } 
 
  
 public void createIndex() { 
  if (canScroll) { 
   mPreIndex = maxItemCount - 1; 
   mCurrentIndex = 0; 
   mNextIndex = 1; 
   mPreView = getChildAt(mPreIndex); 
   mCurrentView = getChildAt(mCurrentIndex); 
   mNextView = getChildAt(mNextIndex); 
  } 
 } 
 
  
 public void setonItemClickListener(onItemClickListener onItemClickListener) { 
  monItemClickListener = onItemClickListener; 
 } 
 
  
 public void setAdapter(CycleScrollAdapter adapter) { 
  mAdapter = adapter; 
 } 
 
  
 public void startScroll() { 
  if (canScroll) { 
   mHandler.post(mScrollTask); 
  } 
 } 
 
  
 public void stopScroll() { 
  mHandler.removeCallbacks(mScrollTask); 
 } 
 
  
 public void delayStartScroll() { 
  if (canScroll) { 
   mHandler.postDelayed(mScrollTask, TOUCH_DELAYMILLIS); 
  } 
 } 
 
 @Override 
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
  super.onMeasure(widthMeasureSpec, heightMeasureSpec); 
  int count = this.getChildCount(); 
  for (int i = 0; i < count; i++) { 
   View child = this.getChildAt(i); 
   child.measure(widthMeasureSpec, heightMeasureSpec); 
  } 
 } 
 
 @Override 
 protected void onLayout(boolean changed, int l, int t, int r, int b) { 
   
  if (reLayout) {// Run one times. 
   for (int i = 0; i < getChildCount(); i++) { 
    View child = this.getChildAt(i); 
    child.setVisibility(View.VISIBLE); 
    child.layout(itemX, getItemY(), itemX + getItemWidth(), 
      getItemY() + getItemHeight()); 
    itemX += getItemMargin(); 
   } 
   reLayout = !reLayout; 
  } 
 } 
 
  
 @Override 
 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, 
   float velocityY) { 
 
  if (e1 == null || e2 == null) { 
   return false; 
  } 
 
  // When deltaX and velocityX not good return false. 
  if (Math.abs(velocityX) < MAX_VELOCITY_X) { 
   return false; 
  } 
 
  // Get the delta x. 
  float deltaX = (e1.getX() - e2.getX()); 
 
   
  mHandler.removeCallbacks(mScrollTask); 
  if (canScroll) { 
   mHandler.postDelayed(mScrollTask, TOUCH_DELAYMILLIS 
     + FLING_DURATION - 1000); 
  } 
 
   
  mFlingX = (int) deltaX; 
 
  // Start scroll with fling x. 
  mScroller.startScroll(0, 0, mFlingX, 0, FLING_DURATION); 
  return false; 
 } 
 
 @Override 
 public void computeScroll() { 
  if (canScroll && mScroller.computeScrollOffset()) { 
    
   int deltaX = mFlingX - mScroller.getCurrX(); 
   scrollView(-deltaX / 10); 
   postInvalidate(); 
  } 
 } 
 
  
 @Override 
 public boolean onTouchEvent(MotionEvent ev) { 
 
  // Get event x,y at parent view. 
  final float x = ev.getX(); 
 
   
  final int rawX = (int) ev.getRawX(); 
  final int rawY = (int) ev.getRawY(); 
 
  switch (ev.getAction()) { 
  case MotionEvent.ACTION_DOWN: 
   // Reset isMoveAction. 
   isMoveAction = false; 
   // Get motionX. 
   mLastMotionX = x; 
   break; 
  case MotionEvent.ACTION_MOVE: 
   // When action move set isMoveAction true. 
   isMoveAction = true; 
   // only support one pointer. 
   if (ev.getPointerCount() == 1) { 
    // Compute delta X. 
    int deltaX = 0; 
    deltaX = (int) (x - mLastMotionX); 
    mLastMotionX = x; 
    // When canScroll is true, scrollView width deltaX. 
    if (canScroll) { 
     scrollView(deltaX); 
    } 
   } 
   break; 
  case MotionEvent.ACTION_UP: 
    
   if (!isMoveAction) { 
    View view = getClickItem(rawX, rawY); 
    if (view != null) { 
     mOnItemClickListener.onItemClick(Integer.valueOf(view 
.getTag().toString())); 
    } 
   } 
   break; 
  } 
  return this.detector.onTouchEvent(ev); 
 } 
 
  
 private View getClickItem(final int rawX, final int rawY) { 
  for (int i = 0; i < getChildCount(); i++) { 
   View child = getChildAt(i); 
   // Get item view rect. 
   Rect rect = new Rect(); 
   child.getGlobalVisibleRect(rect); 
   // If click point on the item view, invoke the click event. 
   if (rect.contains(rawX, rawY)) { 
    return child; 
   } 
  } 
  return null; 
 } 
 
  
 private void scrollView(int deltaX) { 
  // Move child view by deltaX. 
  moveChildView(deltaX); 
  // After move change index. 
  if (deltaX < 0) {// move left 
   // If current at right switch current view to left. 
   switchCurrentViewToLeft(); 
   // change previous current next index. 
   moveTonext(); 
  } else {// move right 
   // If current at left switch current view to right. 
   switchCurrentViewToRight(); 
   // change previous current next index. 
   moveToPre(); 
  } 
  invalidate(); 
 } 
 
  
 private void moveChildView(int deltaX) { 
  for (int i = 0; i < getChildCount(); i++) { 
   View child = getChildAt(i); 
   child.layout(child.getLeft() + deltaX, child.getTop(), 
     child.getRight() + deltaX, child.getBottom()); 
  } 
 } 
 
  
 private void switchCurrentViewToLeft() { 
  if (!mCurrentViewAtLeft) { 
   mPreIndex = mCurrentIndex; 
   mCurrentIndex = mNextIndex; 
   mNextIndex++; 
   if (mNextIndex > maxItemCount - 1) { 
    mNextIndex = 0; 
   } 
   mCurrentView = getChildAt(mCurrentIndex); 
   mPreView = getChildAt(mPreIndex); 
   mNextView = getChildAt(mNextIndex); 
   mCurrentViewAtLeft = !mCurrentViewAtLeft; 
  } 
 } 
 
  
 private void switchCurrentViewToRight() { 
  if (mCurrentViewAtLeft) { 
   mNextIndex = mCurrentIndex; 
   mCurrentIndex = mPreIndex; 
   mPreIndex--; 
   if (mPreIndex < 0) { 
    mPreIndex = maxItemCount - 1; 
   } 
   mCurrentView = getChildAt(mCurrentIndex); 
   mPreView = getChildAt(mPreIndex); 
   mNextView = getChildAt(mNextIndex); 
   mCurrentViewAtLeft = !mCurrentViewAtLeft; 
  } 
 } 
 
  
 private void moveTonext() { 
  if (mCurrentView.getRight() < 0) { 
   mCurrentView.layout(mPreView.getLeft() + getItemMargin(), 
     getItemY(), mPreView.getLeft() + getItemMargin() 
+ getItemWidth(), getItemY() + getItemHeight()); 
 
   if (mCurrentView.getTag() != null) { 
    int listIndex = (Integer) mCurrentView.getTag(); 
    int index = (listIndex + maxItemCount) % mAdapter.getCount(); 
    mAdapter.bindView(mCurrentView, mAdapter.get(index)); 
    mCurrentView.setTag(index); 
   } 
 
   mPreIndex = mCurrentIndex; 
   mCurrentIndex = mNextIndex; 
   mNextIndex++; 
   if (mNextIndex > maxItemCount - 1) { 
    mNextIndex = 0; 
   } 
   mCurrentView = getChildAt(mCurrentIndex); 
   mPreView = getChildAt(mPreIndex); 
   mNextView = getChildAt(mNextIndex); 
   moveTonext(); 
  } 
 } 
 
  
 private void moveToPre() { 
  if (mCurrentView.getLeft() > getScreenWidth()) { 
   mCurrentView.layout(mNextView.getLeft() - getItemMargin(), 
     getItemY(), mNextView.getLeft() - getItemMargin() 
+ getItemWidth(), getItemY() + getItemHeight()); 
 
   if (mCurrentView.getTag() != null) { 
    int listIndex = (Integer) mCurrentView.getTag(); 
    int index = (listIndex - maxItemCount + mAdapter.getCount()) 
      % mAdapter.getCount(); 
    mAdapter.bindView(mCurrentView, mAdapter.get(index)); 
    mCurrentView.setTag(index); 
   } 
 
   mNextIndex = mCurrentIndex; 
   mCurrentIndex = mPreIndex; 
   mPreIndex--; 
   if (mPreIndex < 0) { 
    mPreIndex = maxItemCount - 1; 
   } 
   mCurrentView = getChildAt(mCurrentIndex); 
   mPreView = getChildAt(mPreIndex); 
   mNextView = getChildAt(mNextIndex); 
   moveToPre(); 
  } 
 } 
 
 @Override 
 public boolean onDown(MotionEvent e) { 
  return true; 
 } 
 
 @Override 
 public void onShowPress(MotionEvent e) { 
 } 
 
 @Override 
 public boolean onSingleTapUp(MotionEvent e) { 
  return false; 
 } 
 
 @Override 
 public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, 
   float distanceY) { 
  return false; 
 } 
 
 @Override 
 public void onLongPress(MotionEvent e) { 
 } 
 
 public int getMaxItemCount() { 
  return maxItemCount; 
 } 
 
 public void setMaxItemCount(int maxItemCount) { 
  this.maxItemCount = maxItemCount; 
 } 
 
 public void setReLayout(boolean reLayout) { 
  this.reLayout = reLayout; 
 } 
 
 public void setCanScroll(boolean canScroll) { 
  this.canScroll = canScroll; 
 } 
 
 public int getItemX() { 
  return itemX; 
 } 
 
 public void setItemX(int itemX) { 
  this.itemX = itemX; 
 } 
 
 public int getItemY() { 
  return itemY; 
 } 
 
 public void setItemY(int itemY) { 
  this.itemY = itemY; 
 } 
 
 public int getItemWidth() { 
  return itemWidth; 
 } 
 
 public void setItemWidth(int itemWidth) { 
  this.itemWidth = itemWidth; 
 } 
 
 public int getItemHeight() { 
  return itemHeight; 
 } 
 
 public void setItemHeight(int itemHeight) { 
  this.itemHeight = itemHeight; 
 } 
 
 public int getItemMargin() { 
  return (screenWidth - itemWidth * (maxItemCount - 1) - initItemX * 2)/(maxItemCount - 2) + itemWidth; 
 } 
 
 public int getScreenWidth() { 
  return screenWidth; 
 } 
 
 public void setScreenWidth(int screenWidth) { 
  this.screenWidth = screenWidth; 
 } 
 
 public int getInitItemX() { 
  return initItemX; 
 } 
 
 public void setInitItemX(int initItemX) { 
  this.initItemX = initItemX; 
 } 
 
  
 interface onItemClickListener { 
  public boolean onItemClick(int position); 
 } 
 
} 

CycleScrollAdapter.java

package com.example.test; 
 
import java.util.List; 
 
import android.app.Activity; 
import android.content.Context; 
import android.util.DisplayMetrics; 
import android.view.View; 
 
public abstract class CycleScrollAdapter { 
 
 private List list; 
 private CycleScrollView mCycleScrollView; 
 Context mContext; 
 
  
 public CycleScrollAdapter(List list, CycleScrollView cycleScrollView, 
   Context context) { 
  this.list = list; 
  mContext = context; 
  mCycleScrollView = cycleScrollView; 
  mCycleScrollView.setAdapter(this); 
  GetScreenWidthPixels(); 
  initView(list); 
 } 
 
  
 private void GetScreenWidthPixels() { 
  DisplayMetrics dm = new DisplayMetrics(); 
  Activity a = (Activity) mContext; 
  a.getWindowManager().getDefaultDisplay().getMetrics(dm); 
  mCycleScrollView.setScreenWidth(dm.widthPixels); 
 } 
 
  
 protected void initView(List list) { 
  if (list == null || list.size() == 0) { 
   return; 
  } 
   
  // Clear all view from ViewGroup at first. 
  mCycleScrollView.removeAllViewsInLayout(); 
 
  // Loop list. 
  for (int i = 0; i < list.size(); i++) { 
    
   if (i == mCycleScrollView.getMaxItemCount()) { 
    break; 
   } 
 
    
   if (i == list.size() - 1 
     || i == mCycleScrollView.getMaxItemCount() - 1) { 
    mCycleScrollView.setItemX(mCycleScrollView.getInitItemX()); 
    mCycleScrollView.setReLayout(true); 
   } 
   add(list.get(i), i); 
  } 
 
   
  if (list.size() >= mCycleScrollView.getMaxItemCount()) { 
   mCycleScrollView.setCanScroll(true); 
  } else { 
   mCycleScrollView.setCanScroll(false); 
  } 
 
   
  mCycleScrollView.createIndex(); 
 } 
 
  
 public int getCount() { 
  return list.size(); 
 } 
 
  
 public T get(int index) { 
  return list.get(index); 
 } 
 
  
 public void addItem(T t) { 
  list.add(t); 
  initView(list); 
 } 
 
  
 public void removeItem(T t) { 
  list.remove(t); 
  initView(list); 
 } 
 
  
 private void add(T t, int index) { 
  View view = getView(t); 
  ComputeItemSize(view); 
  mCycleScrollView.addView(view); 
  view.setTag(index); 
 } 
 
  
 private void ComputeItemSize(View view) { 
  if (mCycleScrollView.getItemWidth() == 0 
    || mCycleScrollView.getItemHeight() == 0) { 
   int w = View.MeasureSpec.makeMeasureSpec(0, 
     View.MeasureSpec.UNSPECIFIED); 
   int h = View.MeasureSpec.makeMeasureSpec(0, 
     View.MeasureSpec.UNSPECIFIED); 
   view.measure(w, h); 
   int height = view.getMeasuredHeight(); 
   int width = view.getMeasuredWidth(); 
   mCycleScrollView.setItemHeight(height); 
   mCycleScrollView.setItemWidth(width); 
  } 
 } 
 
  
 public abstract View getView(T t); 
 
  
 public abstract void bindView(View child, T t); 
} 

以上两个是核心类，下面是测试代码。

实现CycleScrollAdapter

AppCycleScrollAdapter.java绑定视图和应用数据

package com.example.test; 
 
import java.util.List; 
 
import android.content.Context; 
import android.content.pm.PackageInfo; 
import android.view.View; 
import android.widget.ImageView; 
import android.widget.TextView; 
 
public class AppCycleScrollAdapter extends CycleScrollAdapter { 
  
 public AppCycleScrollAdapter(List list, 
   CycleScrollView cycleScrollView, Context context) { 
  super(list, cycleScrollView, context); 
 } 
  
 @Override 
 protected void initView(List list) { 
  super.initView(list); 
 } 
 
 @Override 
 public void bindView(View child, PackageInfo pi) { 
  ImageView image = (ImageView) child.findViewById(R.id.item_image); 
  TextView text = (TextView) child.findViewById(R.id.item_text); 
  image.setImageDrawable(pi.applicationInfo.loadIcon(mContext 
    .getPackageManager())); 
  text.setText(pi.applicationInfo.loadLabel(mContext.getPackageManager())); 
 } 
 
 @Override 
 public View getView(PackageInfo pi) { 
  View view = View.inflate(mContext, R.layout.view_item, null); 
  // inflate APP icon view 
  ImageView image = (ImageView) view.findViewById(R.id.item_image); 
  // inflate APP name view 
  TextView text = (TextView) view.findViewById(R.id.item_text); 
  image.setImageDrawable(pi.applicationInfo.loadIcon(mContext 
    .getPackageManager())); 
  text.setText(pi.applicationInfo.loadLabel(mContext.getPackageManager())); 
  return view; 
 } 
} 

入口Activity

package com.example.test; 
 
 
import java.util.List; 
 
 
import android.app.Activity; 
import android.content.pm.PackageInfo; 
import android.os.Bundle; 
import android.view.Menu; 
 
public class MainActivity extends Activity{ 
  
 private CycleScrollView mCycleScrollView; 
 private AppCycleScrollAdapter mAdapter; 
  
 @Override 
 public void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
   
  mCycleScrollView = ((CycleScrollView) this.findViewById(R.id.cycle_scroll_view)); 
 
   
  List list = this.getPackageManager() 
    .getInstalledPackages(0); 
 
  mAdapter = new AppCycleScrollAdapter(list, mCycleScrollView, this); 
   
 } 
  
 
 
 @Override 
 public boolean onCreateOptionsMenu(Menu menu) { 
  getMenuInflater().inflate(R.menu.activity_main, menu); 
  return true; 
 } 
 
} 

布局文件

 
 
 
  
 
  
 
 
[java] view plain copy
 
 
  
  
   
 
 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。