利用ViewGroup实现引导界面

来源：互联网发布：sip udp端口号5060 编辑：程序博客网时间：2024/06/07 02:16

参考博文
App在首次启动时，有一个引导界面，不仅可以给用户绚丽视觉效果，同样可以让用户了解你的App.
下面就来利用自定义ViewGroup来实现安卓的引导界面：
首先我们来实现界面布局：

<com.example.timor.myfirsttext.view.welcomeView xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/id_main_ly"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:background="#fff"    >    <RelativeLayout        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="@mipmap/w02" >    </RelativeLayout>    <RelativeLayout        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="@mipmap/w03" >    </RelativeLayout>    <RelativeLayout        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="@mipmap/w04" >    </RelativeLayout>    <RelativeLayout        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="@mipmap/w05" >        <Button            android:id="@+id/finish"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_centerHorizontal="true"            android:text="确定" />    </RelativeLayout></com.example.timor.myfirsttext.view.welcomeView>

com.example.timor.myfirsttext.view.welcomeView是自定义ViewGroup所在的位置
图片去百度两张就行；

package com.example.timor.myfirsttext.view;import android.content.Context;import android.util.AttributeSet;import android.util.DisplayMetrics;import android.util.Log;import android.view.LayoutInflater;import android.view.MotionEvent;import android.view.VelocityTracker;import android.view.View;import android.view.ViewGroup;import android.view.WindowManager;import android.widget.Button;import android.widget.Scroller;import java.util.zip.Inflater;/** * Created by Timor on 2016/1/16. */public class welcomeView extends ViewGroup {    /**     * 屏幕的高度     */    private int mScreenHeight;    /**     * 手指按下时的getScrollY     */    private int mScrollStart;    /**     * 手指抬起时的getScrollY     */    private int mScrollEnd;    /**     * 记录移动时的Y     */    private int mLastY;    /**     * 滚动的辅助类     */    private Scroller mScroller;    /**     * 是否正在滚动     */    private boolean isScrolling;    /**     * 加速度检测     */    private VelocityTracker mVelocityTracker;    /**     * 记录当前页     */    private int currentPage = 0;    private OnPageChangeListener mOnPageChangeListener;    public welcomeView(Context context, AttributeSet attrs)    {        super(context, attrs);        /**         * 获得屏幕的高度         */        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);        DisplayMetrics outMetrics = new DisplayMetrics();        wm.getDefaultDisplay().getMetrics(outMetrics);        mScreenHeight = outMetrics.heightPixels;        // Scroller初始化        mScroller = new Scroller(context);    }    /**     * 测量子view的值     * @param widthMeasureSpec     * @param heightMeasureSpec     */    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)    {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        int count = getChildCount();        for (int i = 0; i < count; ++i)        {            View childView = getChildAt(i);            measureChild(childView, widthMeasureSpec, heightMeasureSpec);        }    }    /**     * 从新布局     * @param changed     * @param l     * @param t     * @param r     * @param b     */    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b)    {        if (changed)        {            //获取子view个数            int childCount = getChildCount();            // 设置主布局的高度            MarginLayoutParams lp = (MarginLayoutParams) getLayoutParams();            lp.height = mScreenHeight * childCount;            //设置为该控件的layoutParams.            setLayoutParams(lp);            for (int i = 0; i < childCount; i++)            {                View child = getChildAt(i);                if (child.getVisibility() != View.GONE)                {                    // 调用每个自布局的layout                    child.layout(l, i * mScreenHeight, r, (i + 1) * mScreenHeight);                }            }        }    }    @Override    public boolean onTouchEvent(MotionEvent event)    {        // 如果当前正在滚动，调用父类的onTouchEvent        if (isScrolling)            return super.onTouchEvent(event);        int action = event.getAction();        int y = (int) event.getY();        //计算速度        obtainVelocity(event);        switch (action)        {            case MotionEvent.ACTION_DOWN:                mScrollStart = getScrollY();                mLastY = y;                break;            case MotionEvent.ACTION_MOVE:                if (!mScroller.isFinished())                {                    mScroller.abortAnimation();                }                int dy = mLastY - y;                // 边界值检查                int scrollY = getScrollY();                // 已经到达顶端，下拉多少，就往上滚动多少                if (dy < 0 && scrollY + dy < 0)                {                    dy = -scrollY;                }                // 已经到达底部，上拉多少，就往下滚动多少                if (dy > 0 && scrollY + dy > getHeight() - mScreenHeight)                {                    dy = getHeight() - mScreenHeight - scrollY;                }                scrollBy(0, dy);                mLastY = y;                break;            case MotionEvent.ACTION_UP:                mScrollEnd = getScrollY();                int dScrollY = mScrollEnd - mScrollStart;                if (wantScrollToNext())// 往上滑动                {                    if (shouldScrollToNext())                    {                        mScroller.startScroll(0, getScrollY(), 0, mScreenHeight - dScrollY);                    } else                    {                        mScroller.startScroll(0, getScrollY(), 0, -dScrollY);                    }                }                if (wantScrollToPre())// 往下滑动                {                    if (shouldScrollToPre())                    {                        mScroller.startScroll(0, getScrollY(), 0, -mScreenHeight - dScrollY);                    } else                    {                        mScroller.startScroll(0, getScrollY(), 0, -dScrollY);                    }                }                isScrolling = true;                postInvalidate();                recycleVelocity();                break;        }        return true;    }    /**     * 根据滚动距离判断是否能够滚动到下一页     *     * @return     */    private boolean shouldScrollToNext()    {        return mScrollEnd - mScrollStart > mScreenHeight / 2 || Math.abs(getVelocity()) > 600;    }    /**     * 根据用户滑动，判断用户的意图是否是滚动到下一页     *     * @return     */    private boolean wantScrollToNext()    {        return mScrollEnd > mScrollStart;    }    /**     * 根据滚动距离判断是否能够滚动到上一页     *     * @return     */    private boolean shouldScrollToPre()    {        return -mScrollEnd + mScrollStart > mScreenHeight / 2 || Math.abs(getVelocity()) > 600;    }    /**     * 根据用户滑动，判断用户的意图是否是滚动到上一页     *     * @return     */    private boolean wantScrollToPre()    {        return mScrollEnd < mScrollStart;    }    @Override    public void computeScroll()    {        super.computeScroll();        if (mScroller.computeScrollOffset())        {            scrollTo(0, mScroller.getCurrY());            postInvalidate();        } else        {            int position = getScrollY() / mScreenHeight;            Log.e("xxx", position + "," + currentPage);            if (position != currentPage)            {                if (mOnPageChangeListener != null)                {                    currentPage = position;                    mOnPageChangeListener.onPageChange(currentPage);                }            }            isScrolling = false;        }    }    /**     * 获取y方向的加速度     *     * @return     */    private int getVelocity()    {        mVelocityTracker.computeCurrentVelocity(1000);        return (int) mVelocityTracker.getYVelocity();    }    /**     * 释放资源     */    private void recycleVelocity()    {        if (mVelocityTracker != null)        {            mVelocityTracker.recycle();            mVelocityTracker = null;        }    }    /**     * 初始化加速度检测器     * 通过跟踪一连串事件实时计算出当前的速度，     * @param event     */    private void obtainVelocity(MotionEvent event)    {        if (mVelocityTracker == null)        {            //获得VelocityTracker类实例            mVelocityTracker = VelocityTracker.obtain();        }        //将事件加入到VelocityTracker类实例中        mVelocityTracker.addMovement(event);    }    /**     * 设置回调接口     *     * @param onPageChangeListener     */    public void setOnPageChangeListener(OnPageChangeListener onPageChangeListener)    {        mOnPageChangeListener = onPageChangeListener;    }    /**     * 回调接口     *     * @author zhy     *     */    public interface OnPageChangeListener    {        void onPageChange(int currentPage);    }}这里的注释比较详细不在多说在主Activity中只需像普通的ViewGrup那样调用便可

package com.example.timor.myfirsttext;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.example.timor.myfirsttext.utils.SPUtils;
import com.example.timor.myfirsttext.view.welcomeView;
import com.example.timor.myfirsttext.view.welcomeView.OnPageChangeListener;

/**
* Created by Timor on 2016/1/16.
*/
public class Splash extends Activity {

private welcomeView mMianLayout;@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_splash);    Toastevent();    ButtonClick();}private void Toastevent() {    mMianLayout = (welcomeView) findViewById(R.id.id_main_ly);    mMianLayout.setOnPageChangeListener(new OnPageChangeListener() {        @Override        public void onPageChange(int currentPage) {            Toast.makeText(Splash.this, "第" + (currentPage + 1) + "页", Toast.LENGTH_SHORT).show();        }    });}

}

“`
完工；
当然，引导界面只能出现一次，，我们可以用SharedPreferences来判定，这个以后再说

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