动态给ViewPager添加Indicator导航

来源：互联网发布：淘宝火拼编辑：程序博客网时间：2024/06/06 18:31

先看下效果这里写图片描述

小圆点的形状和颜色都是可以自己定义的,看需求

首先第一步,滑2个圆点,一个是选中后的圆点,一个是未选中的圆点,看选中的圆点shape

<?xml version="1.0" encoding="utf-8"?><shape    xmlns:android="http://schemas.android.com/apk/res/android"    android:shape="oval"    >    <solid android:color="@color/colorPrimary"/></shape>

未选中的

<?xml version="1.0" encoding="utf-8"?><shape    xmlns:android="http://schemas.android.com/apk/res/android"    android:shape="oval"    >    <solid android:color="@color/colorAccent"/></shape>

是不是很简单,就指定一个圆形,一个颜色
接下来就是定义一个selector,用来控制选中和非选中

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">    <item android:drawable="@drawable/indicator_checked_shape" android:state_enabled="true"/>    <item android:drawable="@drawable/indicator_unchecked_shape" android:state_enabled="false"/></selector>

然后就是mainActivity的布局文件,放置一个ViewPager,下面放置一个LinearLayout,用来装小圆点

<?xml version="1.0" encoding="utf-8"?><RelativeLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.duanlian.viewpagerindicatordemo.MainActivity">    <android.support.v4.view.ViewPager        android:id="@+id/viewpager"        android:layout_width="match_parent"        android:layout_height="170dp"        />    <LinearLayout        android:id="@+id/linear"        android:layout_width="match_parent"        android:layout_height="40dp"        android:layout_below="@+id/viewpager"        android:layout_marginTop="-40dp"        android:gravity="center"        android:orientation="horizontal"></LinearLayout></RelativeLayout>

接下来就是MainActivity的代码,其实很简单,都有注释,就不细说了

package com.duanlian.viewpagerindicatordemo;import android.os.Bundle;import android.support.v4.view.ViewPager;import android.support.v7.app.AppCompatActivity;import android.widget.ImageView;import android.widget.LinearLayout;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {    private ViewPager mViewPager;    private LinearLayout mLinear;    private List<ImageView> mList;    private PagerAdapter mPagerAdapter;    private int[] imageArray = {R.mipmap.banner1, R.mipmap.banner2, R.mipmap.banner3, R.mipmap.ic_launcher};    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        initPoint();    }    private void initView() {        mViewPager = (ViewPager) findViewById(R.id.viewpager);        mLinear = (LinearLayout) findViewById(R.id.linear);        //给ViewPager添加图片显示        mList = new ArrayList<>();        for (int i = 0; i < imageArray.length; i++) {            ImageView imageView = new ImageView(this);            imageView.setImageResource(imageArray[i]);            mList.add(imageView);        }        mPagerAdapter = new PagerAdapter(mList);        mViewPager.setAdapter(mPagerAdapter);        //ViewPager切换的监听事件        mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {            @Override            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {                position = position % mList.size();// 需要对position的值进行重新赋值，否则会造成数组越界                // 更新小圆点的显示                for (int i = 0; i < mList.size(); i++) {                    ImageView iv = (ImageView) mLinear.getChildAt(i);                    // 当前滑到的是那一页就让第几个小圆点处于选中状态                    if (position == i) {                        iv.setEnabled(true);                    } else {                        iv.setEnabled(false);                    }                }            }            @Override            public void onPageSelected(int position) {            }            @Override            public void onPageScrollStateChanged(int state) {            }        });    }    /**     * 初始化指示器     */    private void initPoint() {        for (int i = 0; i < mList.size(); i++) {            // 往llContainer添加一个小圆点            ImageView iv = new ImageView(this);            //设置背景            iv.setImageResource(R.drawable.indicator_viewpager_selector);            //设置原点大小            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(30, 30);            //如果是切好的图片就直接自适应//            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);            iv.setLayoutParams(params);            // 默认第0个小圆点显示红色            if (i == 0) {                iv.setEnabled(true);            } else {                iv.setEnabled(false);            }            //设置原点之间的间距            iv.setPadding(5, 5, 5, 5);            //添加到LinearLayout中            mLinear.addView(iv);        }    }}

最后附上ViewPager的adapter

package com.duanlian.viewpagerindicatordemo;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import java.util.List;/** * viewPager的adapter */public class PagerAdapter extends android.support.v4.view.PagerAdapter{    private List<ImageView> list;    public PagerAdapter(List<ImageView> list) {        this.list = list;    }    @Override    public int getCount() {        return list.size();    }    @Override    public boolean isViewFromObject(View view, Object object) {        return view==object;    }    @Override    public Object instantiateItem(ViewGroup container, int position) {        container.addView(list.get(position));//添加页卡        return list.get(position);    }    @Override    public void destroyItem(ViewGroup container, int position, Object object) {        container.removeView(list.get(position));//删除页卡    }}

下载地址都在我上传的资源里面点击查看下载的资源

0 0