5.16

今天的任务中使用到了两个fragment，这可以这样就可以通过下方的导航栏来实现页面的切换，方便第二阶段的编写。

其次就是安卓中listview的使用，根据要求的不同通过创建每一行的视图来使用适配器进行绑定，这样也方便设置行点击事件。

//主要的功能代码

package com.example.limit_text.fragment;

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;

import androidx.fragment.app.Fragment;

import com.example.limit_text.Adapter.NameAdpter;
import com.example.limit_text.Pojo.PoilcyPojo;
import com.example.limit_text.PolicyView;
import com.example.limit_text.R;
import com.example.limit_text.util.JDBCUtils;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class FragmentPolicy extends Fragment {
    private EditText key1;
    private Button query;
    private ListView query_result;
    private List<PoilcyPojo> list;
    private NameAdpter nameAdpter;
    @Override
    public View onCreateView(LayoutInflater inflater,
                             ViewGroup container,
                             Bundle savedInstanceState)
    {
        Log.e("已启动","");
        select();
        View policy =LayoutInflater.from(getActivity()).inflate(R.layout.activity_policy,container,false);
        key1=policy.findViewById(R.id.key1);
        query=policy.findViewById(R.id.query);
        query_result=policy.findViewById(R.id.query_result);
        query.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                select();
            }
        });
        query_result.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Intent intent=new Intent(getActivity(), PolicyView.class);
                intent.putExtra("id",list.get(position).getId());
                startActivity(intent);
            }
        });
        return policy;
    }
    private void select()
    {
        list=new ArrayList<>();
        new Thread(new Runnable() {
            @Override
            public void run() {
                Connection coon=null;
                coon= JDBCUtils.getConn();
                String sql;

                if(!key1.getText().toString().isEmpty()) {
                    sql = "select id,name from policy where name like '%"+key1.getText().toString()+"%'";
                }
                else{
                    sql="select id,name from policy";
                }
                try {
                    PreparedStatement ps=coon.prepareStatement(sql);
                    ResultSet resultSet=ps.executeQuery();
                    while (resultSet.next())
                    {
                        PoilcyPojo policy_item=new PoilcyPojo();
                        policy_item.setId(resultSet.getInt(1));
                        policy_item.setName(resultSet.getString(2));
                        list.add(policy_item);
                    }
                    getActivity().runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            nameAdpter=new NameAdpter(list,getActivity());
                            query_result.setAdapter(nameAdpter);
                        }
                    });

                } catch (SQLException e) {
                    throw new RuntimeException(e);
                }
            }
        }).start();
    }
}

//适配器

package com.example.limit_text.Adapter;

import android.annotation.SuppressLint;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.example.limit_text.Pojo.PoilcyPojo;
import com.example.limit_text.R;

import java.util.List;

public class NameAdpter  extends BaseAdapter {

    private List<PoilcyPojo> list;
    private Context context;
    public NameAdpter(List<PoilcyPojo> list, Context context) {
        this.list = list;
        this.context = context;
    }
    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

    @Override
    public long getItemId(int position) {
        return (long)list.get(position).getId();
    }

    @SuppressLint("ViewHolder")
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView = LayoutInflater.from(context).inflate(R.layout.name_view,null);
        PoilcyPojo poilcyPojo=list.get(position);
        TextView name=convertView.findViewById(R.id.name);
        name.setText(poilcyPojo.getName());
        return convertView;
    }
}