排序android系统不工作

Question

林调用collections.sort ArrayList类任用对象的数组列表上，但它不会排序没有任何反应

这是IM调用集合排序

ArrayList<appointment> listoffappointments = new ArrayList<appointment>(); 

//then everytime on button click user adds a new appointment after setting the following code is executed 
{ 
Calendar calendar1 = Calendar.getInstance();     
calendar1.set(mYear, mMonth, mDay, temphour, tempmin); 
appointment tempppt = new appointment(c2,tempstring1); 
listoffappointments.add(tempppt); 
Collections.sort(listoffappointments); 
} 

这里是怎么该类有人可以找到问题的感谢

import java.util.Calendar; 

public class appointment implements Comparable<appointment> { 

Calendar time; 
String Text; 
public appointment(Calendar tempc, String temptext) { 
    Text = temptext; 
    time = tempc; 
} 

public void settext(String text) 
{ 
    Text = text; 
} 
public String gettext() 
{ 
    return Text; 
} 
public String toString() { 
    return Text; 
} 
public Long gettimeofappt() 
{ 
    return time.getTimeInMillis(); 

} 

@Override 
public int compareTo(appointment o) { 
    return (this.gettimeofappt() < o.gettimeofappt()) ? -1: (this.gettimeofappt() > o.gettimeofappt()) ? 1:0 ; 

} 


} 

Answer 1

你是返回一个Long对象，更改您的compareTo，如：

@Override 
public int compareTo(appointment o) { 
    return this.gettimeofappt().compareTo(o.gettimeofappt()); 

} 

Long.compareTo比较两个Long对象数值，和Retunrs：

值0，如果这是长等于参数龙;如果此Long在数字上小于参数Long，则值小于 ;和一个 值大于0，如果此长数字上大于 参数长（有符号比较）。

Answer 2

试试这个：

Collections.sort(list, new Comparator<String>() { 
     @Override 
     public int compare(String s1, String s2) { 
      return s1.compareToIgnoreCase(s2); 
     } 
    }); 

看Sorting ArrayList (String ArrayList and custom class)