Android仿IOS ViewPager滑动进度条

Posted 2022-12-06

最近做项目，碰到如下的需求：ViewPager分页，如果是6页(包括6页)就用圆点，如果是6页以上就用进度条来切换。前面一种交互方法最常见，用小圆点来表示当前选中的页面，这些小圆点称为导航点，很多App都是这种实现方式。当用户第一次安装或升级应用时，都会利用导航页面告诉用户当前版本的主要亮点，一般情况下当行页面有三部分组成，背景图片，导航文字和滑动的原点，即下面的效果：

这里就不作详细的讲解，大家可以参考我以前写过的博客：

​​ViewPager实现图片轮翻效果​​

今天来实现ViewPager进度条切换，主要逻辑如下：

MainActivity.java

package com.jackie.slidebarviewdemo.activity;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

import com.jackie.slidebarviewdemo.R;
import com.jackie.slidebarviewdemo.widget.SlideBarView;

public class MainActivity extends AppCompatActivity 
    private SlideBarView mSlideBarView;
    private TextView mTextView;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mSlideBarView = (SlideBarView) findViewById(R.id.slide_bar);
        mTextView = (TextView) findViewById(R.id.text_view);

        mSlideBarView.setTotalPage(80);
        mSlideBarView.setOnSlideChangeListener(new SlideBarView.OnSlideChangeListener() 
            @Override
            public void onSlideChange(int page) 
                mTextView.setText("当前是第" + page + "页");
            
        );
    

SlideBarView.java

package com.jackie.slidebarviewdemo.widget;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.PopupWindow;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.jackie.slidebarviewdemo.R;
import com.jackie.slidebarviewdemo.utils.ConvertUtils;

/**
 * Created by Jackie on 2017/1/17.
 */

public class SlideBarView extends RelativeLayout 
    private LayoutInflater mInflater;

    private RelativeLayout mSlideBarView;
    private View mSlideBarBlock;

    private PopupWindow mPopupWindow;
    private TextView mPopupText;

    private int mDp40;

    private String mBound = "no"; // no表示没到边界，left为到左边界了，right表示到右边界了

    public interface OnSlideChangeListener 
        void onSlideChange(int page);
    

    private OnSlideChangeListener mOnSlideChangeListener;
    public void setOnSlideChangeListener(OnSlideChangeListener onSlideChangeListener) 
        this.mOnSlideChangeListener = onSlideChangeListener;
    

    public SlideBarView(Context context) 
        this(context, null);
    

    public SlideBarView(Context context, AttributeSet attrs) 
        this(context, attrs, 0);
    

    public SlideBarView(Context context, AttributeSet attrs, int defStyleAttr) 
        super(context, attrs, defStyleAttr);

        init(context);
        initEvent();
    

    private void init(Context context) 
        mInflater = LayoutInflater.from(context);
        View slideBar = mInflater.inflate(R.layout.slide_bar, null);
        LayoutParams params = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
        addView(slideBar, params);

        mSlideBarView = (RelativeLayout) slideBar.findViewById(R.id.slide_bar_view);
        mSlideBarBlock = slideBar.findViewById(R.id.slide_bar_block);

        mDp40 = ConvertUtils.dip2px(context, 40);
    

    private void initEvent() 
        mSlideBarView.setOnTouchListener(new OnTouchListener() 
            int currentX = 0;
            int startX = 0;

            @Override
            public boolean onTouch(View v, MotionEvent event) 
                switch (event.getAction()) 
                    case MotionEvent.ACTION_DOWN:
                        currentX = (int) event.getX();
                        startX = (int) event.getX();

                        // 设置滑块的滑动, 手指第一次点下去把滑块放到手指上
                        int downLeft = currentX - mSlideBarBlock.getMeasuredWidth() / 2;
                        int downTop = mSlideBarBlock.getTop();
                        int downRight = downLeft + mSlideBarBlock.getWidth();
                        int downBottom = mSlideBarBlock.getBottom();

                        //边界检测
                        if (downLeft < 0) 
                            downLeft = 0;
                            downRight = mSlideBarBlock.getMeasuredWidth();
                         else if (downRight > mSlideBarView.getMeasuredWidth()) 
                            downLeft = mSlideBarView.getMeasuredWidth() - mSlideBarBlock.getMeasuredWidth();
                            downRight = mSlideBarView.getMeasuredWidth();
                        

                        mSlideBarBlock.layout(downLeft, downTop, downRight, downBottom);
                        break;
                    case MotionEvent.ACTION_MOVE:
                        currentX = (int) event.getX();
                        int currentPage = currentX * mTotalPage / mSlideBarView.getMeasuredWidth();
                        if (currentPage < 0) 
                            currentPage = 0;
                         else if (currentPage > mTotalPage) 
                            currentPage = mTotalPage;
                        

                        // 设置滑块的滑动
                        int moveLeft = currentX - mSlideBarBlock.getMeasuredWidth() / 2;
                        int moveTop = mSlideBarBlock.getTop();
                        int moveRight = moveLeft + mSlideBarBlock.getMeasuredWidth();
                        int moveBottom = mSlideBarBlock.getBottom();

                        //边界处理
                        if (moveLeft < 0) 
                            mBound = "left";

                            moveLeft = 0;
                            moveRight = mSlideBarBlock.getMeasuredWidth();
                         else if (moveRight >= mSlideBarView.getMeasuredWidth()) 
                            mBound = "right";

                            moveLeft = mSlideBarView.getMeasuredWidth() - mSlideBarBlock.getMeasuredWidth();
                            moveRight = mSlideBarView.getMeasuredWidth();
                         else 
                            mBound = "no";
                        

                        mSlideBarBlock.layout(moveLeft, moveTop, moveRight, moveBottom);
                        startX = currentX;

                        //设置popupWindow的弹出位置
                        if (mOnSlideChangeListener != null) 
                            if (currentPage == mTotalPage) 
                                //防止ViewPager越界
                                currentPage = mTotalPage - 1;
                            

                            mOnSlideChangeListener.onSlideChange(currentPage);

                            if (mPopupWindow != null) 
                                mPopupText.setText(currentPage + "");

                                //设置PopupWindow的滑动
                                if (!mPopupWindow.isShowing()) 
                                    int[] location = new int[2];
                                    mSlideBarView.getLocationInWindow(location);
                                    mPopupWindow.showAsDropDown(mSlideBarView, currentX, location[1] - mDp40);
                                 else 
                                    if ("no".equals(mBound)) 
                                       int[] location = new int[2] ;
                                        mSlideBarView.getLocationInWindow(location);
                                        mPopupWindow.update(currentX, location[1] - mDp40, mPopupWindow.getWidth(), mPopupWindow.getHeight(), true);
                                    
                                
                            
                        
                        break;
                    case MotionEvent.ACTION_UP:
                        currentX = 0;
                        startX = 0;
                        mPopupWindow.dismiss();
                        break;
                

                return true;
            
        );

        // 初始化PopupWindow
        View contentView = mInflater.inflate(R.layout.popup_window, null);
        mPopupText = (TextView) contentView.findViewById(R.id.popup_text);
        mPopupWindow = new PopupWindow(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        mPopupWindow.setContentView(contentView);
        mPopupWindow.setOutsideTouchable(true);
        mPopupWindow.setBackgroundDrawable(getResources().getDrawable(R.mipmap.popup_window_bg));
        mPopupWindow.setAnimationStyle(0);
    

    int mTotalPage = 0;
    public void setTotalPage(int totalPage) 
        this.mTotalPage = totalPage;
    

相关的单位转化工具，大家可以拷贝到自己的项目中直接使用。

ConvertUtils.java

package com.jackie.slidebarviewdemo.utils;

import android.content.Context;

public class ConvertUtils 
    public static int dip2px(Context context, float dpValue) 
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    

    public static int px2dip(Context context, float pxValue) 
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    
    
    public static int px2sp(Context context, float pxValue) 
        final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;  
        return (int) (pxValue / fontScale + 0.5f);  
     
    
    public static int sp2px(Context context, float spValue) 
        final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;  
        return (int) (spValue * fontScale + 0.5f);  
    

自定义组合控件，然后实现相关的手势，思路很清晰，代码也很详细，这里就直接贴代码了。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_
    android:layout_>

    <LinearLayout
        android:layout_
        android:layout_
        android:layout_centerInParent="true"
        android:orientation="vertical">

        <com.jackie.slidebarviewdemo.widget.SlideBarView
            android:id="@+id/slide_bar"
            android:layout_
            android:layout_
            android:layout_marginLeft="20dp"
            android:layout_marginRight="20dp"/>

        <TextView
            android:id="@+id/text_view"
            android:layout_
            android:layout_
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="20dp"
            android:textColor="#000"
            android:textSize="20dp"
            android:text="当前是第0页"/>
    </LinearLayout>
</RelativeLayout>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_
    android:layout_>

    <RelativeLayout
        android:id="@+id/slide_bar_view"
        android:layout_
        android:layout_>

        <View
            android:layout_
            android:layout_
            android:layout_centerInParent="true"
            android:background="@drawable/shape_slide_bar_bg"/>

        <View
            android:id="@+id/slide_bar_block"
            android:layout_
            android:layout_
            android:background="#b9b9b9"
            android:layout_centerVertical="true" />
    </RelativeLayout>
</RelativeLayout>

popup_window.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_
    android:layout_>
    <RelativeLayout
        android:layout_
        android:layout_>
        <TextView
            android:id="@+id/popup_text"
            android:layout_
            android:layout_
            android:textColor="#fff"
            android:textSize="16dp"
            android:gravity="center"
            android:layout_centerInParent="true" />
    </RelativeLayout>
</RelativeLayout>

附上相关的资源文件：

shape_slide_bar_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="#dcdcdc" />
    <corners android:radius="1dp"/>
</shape>

popup_window_bg.9.png

效果如下：