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;
}
}
}