实现可以滑动的GrildView,类似美团网首页的GrildView功能菜单

首先上实现效果图,不会做动态图,就先凑合着看吧

使用了网上的一个开源控件viewpagerindicator,可以自定义切换时候显示的标记,圆点,或者下划线。

GrildView显示的是手机上的全部app,根据计算好的每页显示的数量来动态添加adapter.

public void initViews() {
        final PackageManager packageManager = getPackageManager();
        final Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
        mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
        // get all apps 
        final List<ResolveInfo> apps = packageManager.queryIntentActivities(mainIntent, 0);
        // the total pages
        final int PageCount = (int)Math.ceil(apps.size()/APP_PAGE_SIZE);
        array = new ArrayList<GridView>();
        for (int i=0; i<PageCount; i++) {
            GridView appPage = new GridView(this);
            appPage.setAdapter(new AppAdapter(this, apps, i));
            appPage.setNumColumns(4);
            array.add(appPage); 
        }
    }

下方显示的切换标记其实两行代码就可以搞定了。

mIndicator = (LinePageIndicator)findViewById(R.id.indicator);
mIndicator.setViewPager(viewPager);

然后布局文件中要引用这个自定义View

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white"
    android:orientation="vertical" >

    <android.support.v4.view.ViewPager
        android:id="@+id/myviewpager"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:layout_gravity="center"
        android:scaleType="fitXY" />
    
    <LinearLayout 
        android:id="@+id/liner1"
        android:layout_width="match_parent"
        android:layout_height="20dp"
        android:layout_gravity="center_horizontal"
        android:gravity="center_horizontal"
        android:orientation="horizontal"
        
        ></LinearLayout>
    
    <com.viewpagerindicator.LinePageIndicator
        android:id="@+id/indicator"
        android:layout_width="fill_parent"
        android:layout_height="10dp"
        android:padding="10dip" />

</LinearLayout>

ViewPage滑动Adapter,这个里面可以自定义需求,比如说,你要实现一个可以无限循环滑动的view,那么你可以把最大数量设为500或者1000更大的然后需要处理好异常,addview跟removeview

package cn.example.adapter;

import java.util.List;
import com.viewpagerindicator.IconPagerAdapter;
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.widget.GridView;
public class MyViewPagerAdapter extends PagerAdapter implements
        IconPagerAdapter {
    private List<GridView> array;

    /**
     * 供外部调用(new)的方法
     * 
     * @param context
     *            上下文
     * @param imageViews
     *            添加的序列对象
     */
    public MyViewPagerAdapter(Context context, List<GridView> array) {
        this.array = array;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return array.size();
    }

    @Override
    public boolean isViewFromObject(View arg0, Object arg1) {
        // TODO Auto-generated method stub
        return arg0 == arg1;
    }

    @Override
    public Object instantiateItem(View arg0, int arg1) {
        View view = array.get(arg1);
        ((ViewPager) arg0).addView(array.get(arg1));
        return view;
    }

    @Override
    public void destroyItem(View arg0, int arg1, Object arg2) {
        ((ViewPager) arg0).removeView((View) arg2);
    }

    @Override
    public int getIconResId(int index) {
        // TODO Auto-generated method stub
        return 0;
    }

}

实现GrildView点击事件

package cn.example.adapter;

import java.util.ArrayList;
import java.util.List;

import cn.example.activity.R;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class AppAdapter extends BaseAdapter {
    private List<ResolveInfo> mList;// 定义一个list对象
    private Context mContext;// 上下文
    public static final int APP_PAGE_SIZE = 8;// 每一页装载数据的大小
    private PackageManager pm;// 定义一个PackageManager对象

    /**
     * 构造方法
     * 
     * @param context
     *            上下文
     * @param list
     *            所有APP的集合
     * @param page
     *            当前页
     */
    public AppAdapter(Context context, List<ResolveInfo> list, int page) {
        mContext = context;
        pm = context.getPackageManager();
        mList = new ArrayList<ResolveInfo>();
        // 根据当前页计算装载的应用,每页只装载8个
        int i = page * APP_PAGE_SIZE;// 当前页的其实位置
        int iEnd = i + APP_PAGE_SIZE;// 所有数据的结束位置
        while ((i < list.size()) && (i < iEnd)) {
            mList.add(list.get(i));
            i++;
        }
    }

    public int getCount() {
        // TODO Auto-generated method stub
        return mList.size();
    }

    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return mList.get(position);
    }

    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = LayoutInflater.from(mContext).inflate(
                    R.layout.app_item, parent, false);
        }
        final ResolveInfo appInfo = mList.get(position);
        ImageView appicon = (ImageView) convertView
                .findViewById(R.id.ivAppIcon);
        final TextView appname = (TextView) convertView
                .findViewById(R.id.tvAppName);
        appicon.setImageDrawable(appInfo.loadIcon(pm));
        appname.setText(appInfo.loadLabel(pm));
        convertView.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Toast.makeText(mContext, "点击了" + appInfo.loadLabel(pm),
                        Toast.LENGTH_SHORT).show();
            }
        });
        return convertView;
    }

}

稍后贴出下载连接,CSDN上传出现问题,有需要的可以留邮箱给我。

原文地址:https://www.cnblogs.com/LIANQQ/p/4615291.html