android horizontalscrollview 动画,Android 用HorizontalScrollView实现滑动标签tabView

大体思路： 1.自定义view，实现HorizontalScrollView。 2.在onDraw方法里绘制指示器，(当然也可以用动画的方式实现这个效果) 3.绑定page监听，根据偏移百分比来确定指示器滑动横坐标 4.刷新view. OK，废话不多说，直接上代码，注释写的很详细，就不多说了。

package com.lcworld.tab;

import android.annotation.SuppressLint;

import android.app.Activity;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.os.Build;

import android.support.v4.view.ViewPager;

import android.util.AttributeSet;

import android.util.DisplayMetrics;

import android.util.Log;

import android.view.Gravity;

import android.view.View;

import android.view.ViewGroup;

import android.view.ViewTreeObserver;

import android.view.WindowManager;

import android.widget.HorizontalScrollView;

import android.widget.LinearLayout;

import android.widget.TextView;

import java.util.ArrayList;

import java.util.List;

public class SlideTabView extends HorizontalScrollView implements ViewPager.OnPageChangeListener {

//标签布局容器

private LinearLayout linearLayout;

//指示器画笔

private Paint paint;

//tab容器

private List list;

//text容器

private List textViews;

//当前位置

private int currIndex = 0;

//上一次位置

private int lastIndex = 0;

//满屏显示数量

private float maxCount = 3.5f;

//偏移百分比

private float offSet;

//非选中字体颜色

private int noCurrColor = R.color.noCurrColor;

//选中字体颜色

private int currColor = R.color.currColor;

//指示器颜色

private int offLineColor = R.color.currColor;

//背景色

private int background = R.color.colorPrimary;

//字体大小

private int txtSize = 18;

//viewPager

private ViewPager viewPager;

//上下文

private Context context;

public SlideTabView(Context context) {

this(context, null);

}

public SlideTabView(Context context, AttributeSet attrs) {

this(context, attrs, 0);

}

public SlideTabView(Context context, AttributeSet attrs, int defStyleAttr) {

super(context, attrs, defStyleAttr);

this.context = context;

init();

}

//初始化View

private void init() {

paint = new Paint();

paint.setAntiAlias(true);

paint.setStyle(Paint.Style.FILL);

textViews = new ArrayList<>();

linearLayout = new LinearLayout(context);

linearLayout.setOrientation(LinearLayout.HORIZONTAL);

LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);

linearLayout.setLayoutParams(params);

setBackgroundResource(background);

addView(linearLayout);

}

//初始化tab数据

public void initTab(List list, ViewPager viewPager) {

this.list = list;

this.viewPager = viewPager;

setListener();

addTab();

}

//设置监听

private void setListener() {

viewPager.setOnPageChangeListener(this);

getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

@SuppressWarnings("deprecation")

@SuppressLint("NewApi")

@Override

public void onGlobalLayout() {

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {

getViewTreeObserver().removeGlobalOnLayoutListener(this);

} else {

getViewTreeObserver().removeOnGlobalLayoutListener(this);

}

currIndex = viewPager.getCurrentItem();

scrollToChild(currIndex, 0);

}

});

}

//添加tab 默认选中第一个

private void addTab() {

for (int i = 0; i < list.size(); i++) {

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);

final TextView textView = new TextView(context);

if (i == 0) {

textView.setTextColor(getResources().getColor(currColor));

} else {

textView.setTextColor(getResources().getColor(noCurrColor));

}

layoutParams.setMargins(0, 20, 0, 20);

layoutParams.width = (int) (((float) getWth()) / maxCount);

textView.setLayoutParams(layoutParams);

textView.setGravity(Gravity.CENTER);

textView.setTextSize(txtSize);

textView.setText(list.get(i));

final int finalI = i;

textView.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

if (currIndex != finalI) { //点击的不是当前tab

refresh(finalI);

viewPager.setCurrentItem(finalI);

}

}

});

textViews.add(textView);

linearLayout.addView(textView);

}

invalidate();

}

private void refresh(int index) {

for (int i = 0; i < textViews.size(); i++) {

if (i != index) {

textViews.get(i).setTextColor(getResources().getColor(noCurrColor));

} else {

textViews.get(i).setTextColor(getResources().getColor(currColor));

}

}

}

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

float h = getHeight();

paint.setColor(getResources().getColor(offLineColor));

View view = linearLayout.getChildAt(currIndex);

float lineLeft = view.getLeft();

float lineRight = view.getRight();

if (offSet > 0f) {

View nextTab = linearLayout.getChildAt(currIndex + 1);

final float nextTabLeft = nextTab.getLeft();

final float nextTabRight = nextTab.getRight();

lineLeft = (offSet * nextTabLeft + (1f - offSet) * lineLeft);

lineRight = (offSet * nextTabRight + (1f - offSet) * lineRight);

}

canvas.drawRect(lineLeft, h - 5, lineRight, h, paint);

}

private void scrollToChild(int position, int offset) {

int newScrollX = 0;

if (lastIndex > position) {// 左滑

newScrollX = linearLayout.getChildAt(position).getLeft() - linearLayout.getChildAt(position).getWidth();

} else { //右滑

newScrollX = linearLayout.getChildAt(lastIndex).getLeft() - linearLayout.getChildAt(position).getWidth();

}

Log.e("TAG", "newScrollX:" + newScrollX);

smoothScrollTo(newScrollX, 0);

}

@Override

public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

currIndex = position;

offSet = positionOffset;

invalidate();

}

@Override

public void onPageSelected(int position) {

lastIndex = position;

refresh(position);

}

@Override

public void onPageScrollStateChanged(int state) {

if (state == 0) {

Log.e("TAG", "currIndex:" + currIndex);

if (currIndex != textViews.size() - 1 && currIndex != 0) {

scrollToChild(currIndex, 0);

}

}

}

private int getWth() {

WindowManager manager = ((Activity) context).getWindowManager();

DisplayMetrics displayMetrics = new DisplayMetrics();

manager.getDefaultDisplay().getMetrics(displayMetrics);

return displayMetrics.widthPixels;

}

public void setBackground(int background) {

this.background = background;

}

public void setMaxCount(float maxCount) {

this.maxCount = maxCount;

}

public void setTxtSize(int txtSize) {

this.txtSize = txtSize;

}

public void setOffLineColor(int offLineColor) {

this.offLineColor = offLineColor;

}

public void setCurrColor(int currColor) {

this.currColor = currColor;

}

public void setNoCurrColor(int noCurrColor) {

this.noCurrColor = noCurrColor;

}

}