Android首页左右滑动切换 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;
    }
  }
}