自定义View实现滑屏[Scroller]

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="fill_parent">

	<TextView android:layout_width="fill_parent" android:id="@+id/tv_hello"
		android:layout_height="wrap_content" android:text="@string/hello" />

	<com.qin.scrollerview.MultiViewGroup
		android:id="@+id/mymultiViewGroup" android:layout_below="@id/tv_hello"
		android:layout_height="wrap_content" android:layout_width="wrap_content">
	</com.qin.scrollerview.MultiViewGroup>
	<Button android:id="@+id/bt_scrollLeft"
		android:layout_alignParentBottom="true" android:layout_width="200dip"
		android:layout_height="wrap_content" android:text="@string/hello" />

	<Button android:id="@+id/bt_scrollRight" android:layout_width="200dip"
		android:layout_toRightOf="@id/bt_scrollLeft"
		android:layout_alignParentBottom="true" android:layout_height="wrap_content"
		android:text="@string/hello" />
</RelativeLayout>

package com.qin.scrollerview;

import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.Scroller;

public class MultiScreenActivity extends Activity implements OnClickListener {

    private Button bt_scrollLeft;
    private Button bt_scrollRight;
    private MultiViewGroup mulTiViewGroup;

    public static int screenWidth;
    public static int scrrenHeight; 

    private int curscreen = 0; 

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        DisplayMetrics metric = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metric);
        screenWidth = metric.widthPixels;
        scrrenHeight = metric.heightPixels;

        setContentView(R.layout.multiview);

        mulTiViewGroup = (MultiViewGroup) findViewById(R.id.mymultiViewGroup);

        bt_scrollLeft = (Button) findViewById(R.id.bt_scrollLeft);
        bt_scrollRight = (Button) findViewById(R.id.bt_scrollRight);

        bt_scrollLeft.setOnClickListener(this);
        bt_scrollRight.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {

        switch (v.getId()) {
            case R.id.bt_scrollLeft:
                if (curscreen > 0) {
                    curscreen--;
                }
                //mulTiViewGroup.scrollTo(curscreen * screenWidth, 0);
                 mulTiViewGroup.beginScroll(curscreen * screenWidth,-screenWidth);
                break;
            case R.id.bt_scrollRight:
                if (curscreen < 2) {
                    curscreen++;
                }
                //mulTiViewGroup.scrollTo(curscreen * screenWidth, 0);
                 mulTiViewGroup.beginScroll(curscreen * screenWidth,screenWidth);
                break;
        }
    }

}

package com.qin.scrollerview;
import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Scroller;
public class MultiViewGroup extends ViewGroup {
    private Context mContext;
    private Scroller mScroller = null;
    public MultiViewGroup(Context context) {
        super(context);
        mContext = context;
        mScroller = new Scroller(context);
        init();
    }
    // 在XML 文件中定义的com.qin.scroolerview.MultiViewGroup,会走这个构造方法
    public MultiViewGroup(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        mScroller = new Scroller(context);
        init();
    }
    private void init() {
        LinearLayout oneLL = new LinearLayout(mContext);
        oneLL.setBackgroundColor(Color.RED);
        addView(oneLL);

        LinearLayout twoLL = new LinearLayout(mContext);
        twoLL.setBackgroundColor(Color.YELLOW);
        addView(twoLL);

        LinearLayout threeLL = new LinearLayout(mContext);
        threeLL.setBackgroundColor(Color.BLUE);
        addView(threeLL);
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
        setMeasuredDimension(width, height);

        int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = getChildAt(i);
            child.measure(MultiScreenActivity.screenWidth, MultiScreenActivity.scrrenHeight);
        }
    }
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int startLeft = 0; 
        int startTop = 10; 
        int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = getChildAt(i);
            child.layout(startLeft, startTop,
                    startLeft + MultiScreenActivity.screenWidth,
                    startTop + MultiScreenActivity.scrrenHeight);
            startLeft = startLeft + MultiScreenActivity.screenWidth; 
        }
    }
    @Override
    public void computeScroll() {
        if (mScroller.computeScrollOffset()) {
            scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
            postInvalidate();
        }
    }
    public void beginScroll(int start,int dx) {
        mScroller.startScroll(start, 0, dx, 0, 2000);
        invalidate();
    }
}