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

xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent">

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_centerInParent="true"

android:orientation="vertical">

android:id="@+id/slide_bar"

android:layout_width="match_parent"

android:layout_height="50dp"

android:layout_marginLeft="20dp"

android:layout_marginRight="20dp"/>

android:id="@+id/text_view"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="center_horizontal"

android:layout_marginTop="20dp"

android:textColor="#000"

android:textSize="20dp"

android:text="当前是第0页"/>

activity_main.xml

android:layout_width="match_parent"

android:layout_height="match_parent">

android:id="@+id/slide_bar_view"

android:layout_width="match_parent"

android:layout_height="50dp">

android:layout_width="match_parent"

android:layout_height="5dp"

android:layout_centerInParent="true"

android:background="@drawable/shape_slide_bar_bg"/>

android:id="@+id/slide_bar_block"

android:layout_width="20dp"

android:layout_height="14dp"

android:background="#b9b9b9"

android:layout_centerVertical="true" />

popup_window.xml

android:layout_width="match_parent"

android:layout_height="match_parent">

android:layout_width="30dp"

android:layout_height="30dp">

android:id="@+id/popup_text"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textColor="#fff"

android:textSize="16dp"

android:gravity="center"

android:layout_centerInParent="true" />

附上相关的资源文件：

shape_slide_bar_bg.xml

android:shape="rectangle">

popup_window_bg.9.png

效果如下：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。