Android编程实现的首页左右滑动切换功能示例

/** 滑动后翻页事件 */public interface OnViewChangedListener {  public void OnViewChanged(int viewId);}

import android.content.Context;import android.graphics.Canvas;import android.graphics.PointF;import android.graphics.drawable.Drawable;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.view.ViewConfiguration;import android.widget.FrameLayout;import android.widget.Scroller;public class ScrollerView extends FrameLayout {  private Scroller scroller;  private Drawable drawable;  private OnViewChangedListener listener;  public ScrollerView(Context context) {    this(context, null, 0);  }  public ScrollerView(Context context, AttributeSet attrs) {    this(context, attrs, 0);  }  public ScrollerView(Context context, AttributeSet attrs, int defStyle) {    super(context, attrs, defStyle);    scroller = new Scroller(context);  }  private PointF last = new PointF();  private final int TOUCH_SLOP = ViewConfiguration.get(getContext())      .getScaledTouchSlop();  @Override  public boolean onInterceptTouchEvent(MotionEvent event) {    final int x = (int) event.getX();    boolean flag = false;    switch (event.getAction()) {    case MotionEvent.ACTION_DOWN:      last.x = x;      break;    case MotionEvent.ACTION_MOVE:      final int deltaX = (int) (last.x - x);      if (Math.abs(deltaX) > TOUCH_SLOP) {        flag = true;      }      break;    case MotionEvent.ACTION_UP:      break;    }    return flag;  }  public boolean onTouchEvent(MotionEvent event) {    final int x = (int) event.getX();    final int width = getWidth();    switch (event.getAction()) {    case MotionEvent.ACTION_DOWN:      if (!scroller.isFinished()) {        scroller.abortAnimation();      }      break;    case MotionEvent.ACTION_MOVE:      final int deltaX = (int) (last.x - x);      if (Math.abs(deltaX) < TOUCH_SLOP) {        break;      }      last.x = x;      if (deltaX < 0) {        if (getScrollX() > 0) {          scrollBy(Math.max(-getScrollX(), deltaX), 0);        }      } else if (deltaX > 0) {        final int availableToScroll = getChildAt(getChildCount() - 1)            .getRight() - getScrollX() - getWidth();        if (availableToScroll > 0) {          scrollBy(Math.min(availableToScroll, deltaX), 0);        }      }      break;    case MotionEvent.ACTION_UP:    case MotionEvent.ACTION_CANCEL:      final OnViewChangedListener changedListener = listener;      int dx = (getScrollX() + width / 2) / width;      if (dx < 0) {        dx = 0;      }      if (dx > getChildCount() - 1) {        dx = getChildCount() - 1;      }      changedListener.OnViewChanged(dx);      dx *= width;      dx -= getScrollX();      scroller.startScroll(getScrollX(), 0, dx, 0, Math.abs(dx) * 3);      break;    }    invalidate();    return true;  }  @Override  protected void onLayout(boolean changed, int l, int t, int r, int b) {    final int width = getWidth();    final int count = getChildCount();    int height = getHeight();    int childLeft = 0;    for (int i = 0; i < count; i++) {      final View child = getChildAt(i);      child.layout(childLeft, 0, childLeft + width, height);      childLeft += width;    }  }  @Override  public void setBackgroundDrawable(Drawable d) {    super.setBackgroundDrawable(drawable);    drawable = d;    super.setBackgroundDrawable(null);  }  @Override  protected void dispatchDraw(Canvas canvas) {    if (null != drawable) {      drawable.setBounds(0, 0, getChildCount() * getWidth(), getHeight());      drawable.draw(canvas);    }    super.dispatchDraw(canvas);  }  @Override  public void computeScroll() {    if (scroller.computeScrollOffset()) {      scrollTo(scroller.getCurrX(), scroller.getCurrY());      invalidate();    }  }  /** 设置滑动后翻页事件监听 */  public void setOnViewChangedListener(OnViewChangedListener listener) {    this.listener = listener;  }}

import android.app.Activity;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.Window;import android.widget.ImageView;public class MainActivity extends Activity implements OnViewChangedListener {  private ScrollerView container;  private View view_1, view_2;  private ImageView imgLeft, imgRight;  @Override  public void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    requestWindowFeature(Window.FEATURE_NO_TITLE);    setContentView(R.layout.main);    initView();  }  private void initView() {    LayoutInflater inflater = LayoutInflater.from(this);    container = (ScrollerView) findViewById(R.id.main_container);    container.setOnViewChangedListener(this);    imgLeft = (ImageView) findViewById(R.id.img_left);    imgRight = (ImageView) findViewById(R.id.img_right);    view_1 = inflater.inflate(R.layout.layout_view_1, null);    view_2 = inflater.inflate(R.layout.layout_view_2, null);    container.addView(view_1);    container.addView(view_2);  }  @Override  public void OnViewChanged(int viewId) {    switch (viewId) {    case 0:      imgLeft.setImageResource(R.drawable.main_icon_check);      imgRight.setImageResource(R.drawable.main_icon_normal);      break;    case 1:      imgLeft.setImageResource(R.drawable.main_icon_normal);      imgRight.setImageResource(R.drawable.main_icon_check);      break;    }  }}