基础的增删改查做完了，剩下的就是界面的优化以及一些功能的改进。

 

 

package com.example.myapplicationthree;

import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
public class MainActivity extends Activity {
    private static String DB_NAME = "mydb";
    private EditText et_leixing;
    private EditText et_riqi;
    private EditText et_jine;
    private EditText et_beizhu;
    private ArrayList<Map<String, Object>> data;
    private dbHelper dbHelper;
    private SQLiteDatabase db;
    private Cursor cursor;
    private SimpleAdapter listAdapter;
    private View view;
    private ListView listview;
    private Button selBtn, addBtn, updBtn, delBtn;
    private Map<String, Object> item;
    private String selId;
    private ContentValues selCV;
    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        et_leixing = (EditText) findViewById(R.id.et_leixing);
        et_riqi = (EditText) findViewById(R.id.et_riqi);
        et_jine = (EditText) findViewById(R.id.et_jine);
        et_beizhu = (EditText) findViewById(R.id.et_beizhu);
        listview = (ListView) findViewById(R.id.listView);
        selBtn = (Button) findViewById(R.id.bt_query);
        addBtn = (Button) findViewById(R.id.bt_add);
        updBtn = (Button) findViewById(R.id.bt_modify);
        delBtn = (Button) findViewById(R.id.bt_del);
        selBtn.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                dbFindAll();
            }
        });
        addBtn.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                dbAdd();
                dbFindAll();
            }
        });
        updBtn.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                dbUpdate();
                dbFindAll();
            }
        });
        delBtn.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                dbDel();
                dbFindAll();
            }
        });
        dbHelper = new dbHelper(this, DB_NAME, null, 1);
        db = dbHelper.getWritableDatabase();// 打开数据库
        data = new ArrayList<Map<String, Object>>();
        dbFindAll();
        listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
                // TODO Auto-generated method stub
                Map<String, Object> listItem = (Map<String, Object>) listview.getItemAtPosition(position);
                et_leixing.setText((String) listItem.get("leixing"));
                et_riqi.setText((String) listItem.get("riqi"));
                et_jine.setText((String) listItem.get("jine"));
                et_beizhu.setText((String) listItem.get("beizhu"));
                selId = (String) listItem.get("_id");
                Log.i("mydbDemo", "id=" + selId);
            }
        });
    }
    //数据删除
    protected void dbDel() {
        // TODO Auto-generated method stub
        String where = "_id=" + selId;
        int i = db.delete(dbHelper.TB_NAME, where, null);
        if (i > 0)
            Log.i("myDbDemo", "数据删除成功!");
        else
            Log.i("myDbDemo", "数据未删除!");
    }
    private void showList() {
        // TODO Auto-generated method stub
        listAdapter = new SimpleAdapter(this, data,
                R.layout.listview, new String[]{"_id", "leixing", "riqi","jine","beizhu"}, new int[]{R.id.tvID, R.id.tvLX, R.id.tvRQ, R.id.tvJE, R.id.tvBZ});
        listview.setAdapter(listAdapter);
    }
    //更新列表中的数据
    protected void dbUpdate() {
        // TODO Auto-generated method stub
        ContentValues values = new ContentValues();
        values.put("leixing", et_leixing.getText().toString().trim());
        values.put("riqi", et_riqi.getText().toString().trim());
        values.put("jine", et_jine.getText().toString().trim());
        values.put("beizhu", et_beizhu.getText().toString().trim());
        String where = "_id=" + selId;
        int i = db.update(dbHelper.TB_NAME, values, where, null);
        if (i > 0)
            Log.i("myDbDemo", "数据更新成功！");
        else
            Log.i("myDbDemo", "数据未更新");
    }
    //插入数据
    protected void dbAdd() {
        // TODO Auto-generated method stub
        ContentValues values = new ContentValues();
        values.put("leixing", et_leixing.getText().toString().trim());
        values.put("riqi", et_riqi.getText().toString().trim());
        values.put("jine", et_jine.getText().toString().trim());
        values.put("beizhu", et_beizhu.getText().toString().trim());
        long rowid = db.insert(dbHelper.TB_NAME, null, values);
        if (rowid == -1)
            Log.i("myDbDemo", "数据插入失败！");
        else
            Log.i("myDbDemo", "数据插入成功!" + rowid);
    }
    //查询数据
    protected void dbFindAll() {
        // TODO Auto-generated method stub
        data.clear();
        cursor = db.query(dbHelper.TB_NAME, null, null, null, null, null, "_id ASC");
        cursor.moveToFirst();
        while (!cursor.isAfterLast()) {
            String id = cursor.getString(0);
            String leixing = cursor.getString(1);
            String jine = cursor.getString(2);
            String riqi = cursor.getString(3);
            String beizhu = cursor.getString(4);
            item = new HashMap<String, Object>();
            item.put("_id", id);
            item.put("leixing", leixing);
            item.put("jine", jine);
            item.put("riqi", riqi);
            item.put("beizhu", beizhu);
            data.add(item);
            cursor.moveToNext();
        }
        showList();
    }
}

View Code

package com.example.myapplicationthree;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class dbHelper extends SQLiteOpenHelper {
    public static final String TB_NAME = "friends";
    public dbHelper(Context context, String name, CursorFactory factory, int version) {
        super(context, name, factory, version);
        // TODO Auto-generated constructor stub
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL("CREATE TABLE IF NOT EXISTS " +
                TB_NAME + " ( _id integer primary key autoincrement," +
                "leixing varchar," +
                "riqi varcher,"+
                "jine integer,"+
                "beizhu varcher" +
                ") ");
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS " + TB_NAME);
        onCreate(db);
    }
}

View Code

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:addStatesFromChildren="true">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="类型"
            android:textColor="?android:attr/textColorSecondary" />

        <EditText
            android:id="@+id/et_leixing"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:singleLine="true" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:addStatesFromChildren="true">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="日期"
            android:textColor="?android:attr/textColorSecondary" />

        <EditText
            android:id="@+id/et_riqi"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:singleLine="true" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:addStatesFromChildren="true">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="金额"
            android:textColor="?android:attr/textColorSecondary" />

        <EditText
            android:id="@+id/et_jine"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:singleLine="true" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:addStatesFromChildren="true">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="备注"
            android:textColor="?android:attr/textColorSecondary" />

        <EditText
            android:id="@+id/et_beizhu"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:singleLine="true" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:addStatesFromChildren="true"
        android:gravity="center">

        <Button
            android:id="@+id/bt_add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="addbutton"
            android:text="添加">
        </Button>

        <Button
            android:id="@+id/bt_modify"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="updatebutton"
            android:text="修改">
        </Button>

        <Button
            android:id="@+id/bt_del"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="updatebutton"
            android:text="删除">
        </Button>

        <Button
            android:id="@+id/bt_query"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="querybutton"
            android:text="查询">
        </Button>

    </LinearLayout>

    <ListView
        android:id="@+id/listView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:padding="5dip">
    </ListView>
</LinearLayout>

View Code

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/linear"
    android:layout_width="fill_parent"
    android:layout_height="50dp"
    android:orientation="vertical"
    android:padding="5dip">

    <LinearLayout
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:layout_width="fill_parent"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/tvID"
            android:layout_width="80dp"
            android:layout_height="wrap_content" />

        <TextView
            android:id="@+id/tvLX"
            android:layout_width="80dp"
            android:layout_height="wrap_content" />

        <TextView
            android:id="@+id/tvRQ"
            android:layout_width="80dp"
            android:layout_height="wrap_content" />

        <TextView
            android:id="@+id/tvJE"
            android:layout_width="80dp"
            android:layout_height="wrap_content" />

    </LinearLayout>

    <LinearLayout
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:layout_width="fill_parent"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/tvBZ"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" />

    </LinearLayout>

</LinearLayout>

View Code