Question

我有一个ArrayList，其中的代码由此代码生成并存储：

btSubmit.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            members.add(new member (name, id, mail, ccard, address));
            Toast.makeText(MemReg_activity.this, "Member Added", Toast.LENGTH_LONG).show(); 
            etname.setText("");
        }
    });

现在我想通过name从其他活动中搜索此列表有没有办法做到这一点？如果没有，除了使用ArrayList之外还有其他方法可以帮助我做到这一点吗？

会员班

package com.fawzyx.movie_rental_store;

public class Member extends Customer {

    String id;
    String mail;
    String ccard;
    String address;

    public Member (String name, String id, String mail, String ccard, String address) {
        this.name = name; 
        this.id = id;
        this.mail = mail;
        this.ccard = ccard;
        this.address = address;
    }

    public String getName()
    {
        return name;    
    }
}

Answer 1

如果member是唯一的，name name的查找方法：

public Member findMemberByName(String name) {
    // go through list of members and compare name with given name
    for(Member member : members) {
        if (member.getname().equals(name)) {
            return member; // return member when name found
        }
    }
    return null; // return null when no member with given name could be found
}

如果name不唯一，则该方法会返回包含所有匹配项的ArrayList

public ArrayList<Member> findMemberByName(String name) {
    ArrayList<Member> matches = new ArrayList<Member>();
    // go through list of members and compare name with given name
    for(Member member : members) {
        if (member.getname().equals(name)) {
            matches.add(member); // adds matching member to the return list
        }
    }
    return matches; // return the matches, which is empty when no member with the given name was found
}

要在另一个Activity中执行此操作，您必须将members传递给此其他活动。见Starting another Activity

Answer 2

如果您正在搜索一次，请循环播放。如果您将列表一次并多次搜索，则可能需要创建一个单独的哈希映射，其中名称为键，对象列表为值。然后你可以简单地查找键来获得匹配的每个对象。

按对象的某个属性搜索对象的ArrayList

2 个答案: