android中listview与SQLite怎么实现记事本功能

今天小编给大家分享一下android中listview与SQLite怎么实现记事本功能的相关知识点，内容详细，逻辑清晰，相信大部分人都还太了解这方面的知识，所以分享这篇文章给大家参考一下，希望大家阅读完这篇文章后有所收获，下面我们一起来了解一下吧。

效果：

MainActivity：

import android.app.Activity; import android.app.AlertDialog.Builder; import android.content.DialogInterface; import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.AdapterView.OnItemLongClickListener; import android.widget.Button; import android.widget.ListView; import android.widget.SimpleAdapter; import android.widget.TextView;  import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map;  public class MainActivity extends Activity implements   OnItemClickListener, OnItemLongClickListener {   private ListView listview;  private SimpleAdapter simple_adapter;  private List> dataList;  private Button addNote;  private TextView tv_content;  private NoteDateBaseHelper DbHelper;  private SQLiteDatabase DB;   @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);    InitView();  }   //在activity显示的时候更新listview  @Override  protected void onStart() {   super.onStart();   RefreshNotesList();  }    private void InitView() {   tv_content = (TextView) findViewById(R.id.tv_content);   listview = (ListView) findViewById(R.id.listview);   dataList = new ArrayList>();   addNote = (Button) findViewById(R.id.btn_editnote);   DbHelper = new NoteDateBaseHelper(this);   DB = DbHelper.getReadableDatabase();    listview.setOnItemClickListener(this);   listview.setOnItemLongClickListener(this);   addNote.setOnClickListener(new OnClickListener() {     @Override    public void onClick(View arg0) {     Intent intent = new Intent(MainActivity.this, noteEdit.class);     Bundle bundle = new Bundle();     bundle.putString("info", "");     bundle.putInt("enter_state", 0);     intent.putExtras(bundle);     startActivity(intent);    }   });  }    //刷新listview  public void RefreshNotesList() {   //如果dataList已经有的内容，全部删掉   //并且更新simp_adapter   int size = dataList.size();   if (size > 0) {    dataList.removeAll(dataList);    simple_adapter.notifyDataSetChanged();   }    //从数据库读取信息   Cursor cursor = DB.query("note", null, null, null, null, null, null);   startManagingCursor(cursor);   while (cursor.moveToNext()) {    String name = cursor.getString(cursor.getColumnIndex("content"));    String date = cursor.getString(cursor.getColumnIndex("date"));    Map map = new HashMap();    map.put("tv_content", name);    map.put("tv_date", date);    dataList.add(map);   }   simple_adapter = new SimpleAdapter(this, dataList, R.layout.item,     new String[]{"tv_content", "tv_date"}, new int[]{     R.id.tv_content, R.id.tv_date});   listview.setAdapter(simple_adapter);  }     // 点击listview中某一项的点击监听事件  @Override  public void onItemClick(AdapterView arg0, View arg1, int arg2, long arg3) {   //获取listview中此个item中的内容   String content = listview.getItemAtPosition(arg2) + "";   String content1 = content.substring(content.indexOf("=") + 1,     content.indexOf(","));    Intent myIntent = new Intent(MainActivity.this, noteEdit.class);   Bundle bundle = new Bundle();   bundle.putString("info", content1);   bundle.putInt("enter_state", 1);   myIntent.putExtras(bundle);   startActivity(myIntent);   }   // 点击listview中某一项长时间的点击事件  @Override  public boolean onItemLongClick(AdapterView arg0, View arg1, final int arg2,          long arg3) {   Builder builder = new Builder(this);   builder.setTitle("删除该日志");   builder.setMessage("确认删除吗？");   builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {    @Override    public void onClick(DialogInterface dialog, int which) {     //获取listview中此个item中的内容     //删除该行后刷新listview的内容     String content = listview.getItemAtPosition(arg2) + "";     String content1 = content.substring(content.indexOf("=") + 1,       content.indexOf(","));     DB.delete("note", "content = ?", new String[]{content1});     RefreshNotesList();    }   });   builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {    @Override    public void onClick(DialogInterface dialog, int which) {    }   });   builder.create();   builder.show();   return true;  }

NoteDateBaseHelper:

import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper;  public class NoteDateBaseHelper extends SQLiteOpenHelper {   public static final String CreateNote = "create table note ("    + "id integer primary key autoincrement, "    + "content text , "    + "date text)";   public NoteDateBaseHelper(Context context) {   super(context, "note", null, 1);  }   @Override  public void onCreate(SQLiteDatabase db) {   db.execSQL(CreateNote);  }   @Override  public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {   // TODO Auto-generated method stub   }   }

noteEdit：

import android.app.Activity; import android.content.ContentValues; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast;  import java.text.SimpleDateFormat; import java.util.Date;  public class noteEdit extends Activity implements OnClickListener {  private TextView tv_date;  private EditText et_content;  private Button btn_ok;  private Button btn_cancel;  private NoteDateBaseHelper DBHelper;  public int enter_state = 0;//用来区分是新建一个note还是更改原来的note  public String last_content;//用来获取edittext内容   @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.edit);    InitView();  }   private void InitView() {   tv_date = (TextView) findViewById(R.id.tv_date);   et_content = (EditText) findViewById(R.id.et_content);   btn_ok = (Button) findViewById(R.id.btn_ok);   btn_cancel = (Button) findViewById(R.id.btn_cancel);   DBHelper = new NoteDateBaseHelper(this);    //获取此时时刻时间   Date date = new Date();   SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");   String dateString = sdf.format(date);   tv_date.setText(dateString);    //接收内容和id   Bundle myBundle = this.getIntent().getExtras();   last_content = myBundle.getString("info");   enter_state = myBundle.getInt("enter_state");   et_content.setText(last_content);    btn_cancel.setOnClickListener(this);   btn_ok.setOnClickListener(this);  }   @Override  public void onClick(View view) {   switch (view.getId()) {    case R.id.btn_ok:     SQLiteDatabase db = DBHelper.getReadableDatabase();     // 获取edittext内容     String content = et_content.getText().toString();      // 添加一个新的日志     if (enter_state == 0) {      if (!content.equals("")) {       //获取此时时刻时间       Date date = new Date();       SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");       String dateString = sdf.format(date);        //向数据库添加信息       ContentValues values = new ContentValues();       values.put("content", content);       values.put("date", dateString);       db.insert("note", null, values);       finish();      } else {       Toast.makeText(noteEdit.this, "请输入你的内容！", Toast.LENGTH_SHORT).show();      }     }     // 查看并修改一个已有的日志     else {      ContentValues values = new ContentValues();      values.put("content", content);      db.update("note", values, "content = ?", new String[]{last_content});      finish();     }     break;    case R.id.btn_cancel:     finish();     break;   }  } }

activity_main:

edit:

item：

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