最近项目需要用到时间轴的效果,网上看了几个例子,和想要实现的效果也不尽相同,下面将我的实现方法和思路说一下。首先看下效果图:
数据是随便填的,显得有点乱,但是不影响效果。实现方面主要是用ListView来实现,主要是根据ListView的item位置与上一条数据进行比较,来控制时间的显示隐藏效果。思路很简单,下面看代码实现:
首先是页面的整体布局,很简单,就一个ListView:
res/layout/activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="@+id/lv_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:cacheColorHint="@null"
android:divider="@null" >
</ListView>
</LinearLayout>
ListView的item的布局分了三部分,一个需要显示隐藏的标题栏,包括一个小圆点和一个显示时间的TextView,第二部分是展示的内容,最后是时间轴的竖线。
res/layout/item_time_line.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<RelativeLayout
android:id="@+id/rl_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="10dp" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginLeft="8dp"
android:background="@drawable/img_line_point" />
<TextView
android:id="@+id/txt_date_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginLeft="15dp"
android:textColor="#FC6802" />
</RelativeLayout>
<TextView
android:id="@+id/txt_date_content"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/rl_title"
android:layout_marginLeft="15dp"
android:paddingBottom="10dp"
android:textColor="#5296C5" />
<View
android:id="@+id/v_line"
android:layout_width="2dp"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:background="#FC6802" />
</RelativeLayout>
下面看主要的实现部分,是在listview的适配器中:
DateAdapter.java
package com.xiaowu.timeline;
import java.util.List;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.RelativeLayout;
import android.widget.RelativeLayout.LayoutParams;
import android.widget.TextView;
public class DateAdapter extends BaseAdapter {
private Context context;
private List<DateText> list;
public DateAdapter(Context context, List<DateText> list) {
this.context = context;
this.list = list;
}
@Override
public int getCount() {
if (list == null) {
return 0;
}
return list.size();
}
@Override
public Object getItem(int position) {
if (list == null) {
return null;
}
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
holder = new ViewHolder();
convertView = LayoutInflater.from(context).inflate(
R.layout.item_time_line, parent, false);
holder.date = (TextView) convertView
.findViewById(R.id.txt_date_time);
holder.content = (TextView) convertView
.findViewById(R.id.txt_date_content);
holder.line = (View) convertView.findViewById(R.id.v_line);
holder.title = (RelativeLayout) convertView
.findViewById(R.id.rl_title);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
//时间轴竖线的layout
LayoutParams params = (LayoutParams) holder.line.getLayoutParams();
//第一条数据,肯定显示时间标题
if (position == 0) {
holder.title.setVisibility(View.VISIBLE);
holder.date.setText(TimeFormat.format("yyyy.MM.dd",
list.get(position).getDate()));
params.addRule(RelativeLayout.ALIGN_TOP, R.id.rl_title);
params.addRule(RelativeLayout.ALIGN_BOTTOM, R.id.txt_date_content);
} else { // 不是第一条数据
// 本条数据和上一条数据的时间戳相同,时间标题不显示
if (list.get(position).getDate()
.equals(list.get(position - 1).getDate())) {
holder.title.setVisibility(View.GONE);
params.addRule(RelativeLayout.ALIGN_TOP, R.id.txt_date_content);
params.addRule(RelativeLayout.ALIGN_BOTTOM,
R.id.txt_date_content);
} else {
//本条数据和上一条的数据的时间戳不同的时候,显示数据
holder.title.setVisibility(View.VISIBLE);
holder.date.setText(TimeFormat.format("yyyy.MM.dd",
list.get(position).getDate()));
params.addRule(RelativeLayout.ALIGN_TOP, R.id.rl_title);
params.addRule(RelativeLayout.ALIGN_BOTTOM,
R.id.txt_date_content);
}
}
holder.line.setLayoutParams(params);
holder.content.setText(list.get(position).getText());
return convertView;
}
public static class ViewHolder {
RelativeLayout title;
View line;
TextView date;
TextView content;
}
}
其中DateText是实体类,包括标题和内容:
DateText.java
package com.xiaowu.timeline;
public class DateText {
private String date;
private String text;
public DateText() {
}
public DateText(String date, String text) {
super();
this.date = date;
this.text = text;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getText() {
return text;
}
public void setText(String text) {
this.text = text;
}
}
adapter里面用到了一个时间戳转为指定格式的工具类:
TimeFormat.java
package com.xiaowu.timeline;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class TimeFormat {
public static String format(String format, String time) {
String result = "";
SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd");
try {
Date date = df.parse(time);
SimpleDateFormat df1 = new SimpleDateFormat(format);
result = df1.format(date);
} catch (ParseException e) {
e.printStackTrace();
}
return result;
}
}
场景类中还用到一个比较时间戳的工具类:
DateComparator.java
package com.xiaowu.timeline;
import java.util.Comparator;
public class DateComparator implements Comparator<DateText> {
@Override
public int compare(DateText lhs, DateText rhs) {
return rhs.getDate().compareTo(lhs.getDate());
}
}
下面看下场景类:
MainActivity.java
package com.xiaowu.timeline;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
public class MainActivity extends Activity {
// 时间轴列表
private ListView lvList;
// 数据list
private List<DateText> list;
// 列表适配器
private DateAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// findviewbyid
lvList = (ListView) findViewById(R.id.lv_list);
list = new ArrayList<DateText>();
// 添加测试数据
addData();
// 将数据按照时间排序
DateComparator comparator = new DateComparator();
Collections.sort(list, comparator);
// listview绑定适配器
adapter = new DateAdapter(this, list);
lvList.setAdapter(adapter);
}
private void addData() {
DateText date1 = new DateText("20140710", "撒大声地");
DateText date2 = new DateText("20140709", "撒萨达");
DateText date3 = new DateText("20140726", "撒大ADS");
DateText date4 = new DateText("20140710", "撒达到对萨达撒地");
DateText date5 = new DateText("20140711", "撒大阿瑟的萨达地");
DateText date6 = new DateText("20140713", "撒撒大大地");
DateText date7 = new DateText("20140712", "撒大鼎折覆餗地");
DateText date8 = new DateText("20140714", "撒大请问阿尔阿斯顿");
DateText date9 = new DateText("20140709", "撒大亲爱额问问乔恩地");
DateText date10 = new DateText("20140705", "撒 请问请问地");
DateText date11 = new DateText("20140729", "撒请问额外确认声地");
DateText date12 = new DateText("20140725", "撒大按时打算");
DateText date13 = new DateText("20140716", "撒大爱上大声地");
DateText date14 = new DateText("20140711", "撒其味无穷地");
DateText date15 = new DateText("20140710", "撒大请问我期待地");
DateText date16 = new DateText("20140711", "撒大声萨达");
DateText date17 = new DateText("20140712", "阿斯达");
DateText date18 = new DateText("20140711", "撒大声大声道");
DateText date19 = new DateText("20140715", "阿斯顿撒打算23 ");
DateText date20 = new DateText("20140723", "范德萨发生");
DateText date21 = new DateText("20140718", "阿萨德飞洒");
DateText date22 = new DateText("20140706", "撒打算打算");
DateText date23 = new DateText("20140714", "撒打算");
DateText date24 = new DateText("20140726", "轻微的城市的方式");
DateText date25 = new DateText("20140725", "阿斯达阿斯达现在");
DateText date26 = new DateText("20140723", "代购费多少自行车");
DateText date27 = new DateText("20140721", "多撒阿萨德时打算");
DateText date28 = new DateText("20140716", "爱上大声地啊地");
DateText date29 = new DateText("20140712", "阿斯蒂芬当我师傅");
DateText date30 = new DateText("20140710", "撒大声大声道");
list.add(date1);
list.add(date2);
list.add(date3);
list.add(date4);
list.add(date5);
list.add(date6);
list.add(date7);
list.add(date8);
list.add(date9);
list.add(date10);
list.add(date11);
list.add(date12);
list.add(date13);
list.add(date14);
list.add(date15);
list.add(date16);
list.add(date17);
list.add(date18);
list.add(date19);
list.add(date20);
list.add(date21);
list.add(date22);
list.add(date23);
list.add(date24);
list.add(date25);
list.add(date26);
list.add(date27);
list.add(date28);
list.add(date29);
list.add(date30);
}
}
OK,这样就可以实现图示的效果了。