android实现记事本app

自己写的一个简单的记事本app，效果如下：

一、首先是第一个界面的编写，最上面是一个textview，中间是一个linearlayout中嵌套一个listview布局，最下面是一个button。下面附上第一个页面的简单布局xml文件。

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" 
 android:layout_width="fill_parent" 
 android:layout_height="fill_parent" 
 android:background="@android:color/darker_gray" 
 android:orientation="vertical" > 
 <textview 
 android:layout_height="wrap_content" 
 android:layout_width="fill_parent" 
 android:text="记事本列表" 
 android:textsize="20sp" 
 android:paddingtop="10dp" 
 android:paddingbottom="5dp" 
 android:background="#039dcf" 
 android:gravity="center"/> 
 
 <linearlayout 
 android:layout_width="fill_parent" 
 android:layout_height="fill_parent" 
 android:layout_weight="1" > 
 
 <listview 
  android:id="@+id/listview" 
  android:layout_margin="5dp" 
  android:background="#81966f" 
  android:layout_width="match_parent" 
  android:layout_height="wrap_content" > 
 </listview> 
 </linearlayout> 
 
 <button 
 android:id="@+id/btn_editnote" 
 android:layout_width="fill_parent" 
 android:layout_height="wrap_content" 
 android:background="@drawable/btn_selctor" 
 android:layout_gravity="center" 
 android:layout_marginbottom="10dp" 
 android:text="添加备忘录" 
 android:textsize="20sp" /> 
 
</linearlayout>

 至于button的样式btn_selector就是自己定义的button样式。

二、其次就是设置listview中数据显示的xml文件，代码如下：

<?xml version="1.0" encoding="utf-8"?> 
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:orientation="vertical" > 
 
 <textview 
 android:id="@+id/tv_content" 
 android:layout_width="match_parent" 
 android:layout_height="wrap_content" 
 android:layout_marginleft="10dp" 
 android:singleline="true" 
 android:text="large text" 
 android:textappearance="?android:attr/textappearancelarge" /> 
 
 <textview 
 android:id="@+id/tv_date" 
 android:layout_width="fill_parent" 
 android:layout_height="wrap_content" 
 android:layout_marginleft="10dp" 
 android:text="textview" /> 
 
</linearlayout> 

三、编写第二个界面样式，第二个界面是最上面一个linearlayout，里面包含两个button和一个textview。代码如下：

<?xml version="1.0" encoding="utf-8"?> 
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:background="#ffae99" 
 android:orientation="vertical" > 
 
 <linearlayout 
 android:layout_width="match_parent" 
 android:layout_height="wrap_content" > 
 
 <button 
  android:id="@+id/btn_cancel" 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" 
  android:background="@drawable/btn_selctor" 
  android:text="取消" /> 
 
 <linearlayout 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" 
  android:layout_gravity="center" 
  android:layout_weight="1" 
  android:orientation="vertical" > 
 
  <textview 
  android:layout_width="fill_parent" 
  android:layout_height="wrap_content" 
  android:gravity="center" 
  android:text="编辑备忘录" 
  android:textsize="20sp" /> 
 
  <textview 
  android:id="@+id/tv_date" 
  android:layout_width="fill_parent" 
  android:layout_height="wrap_content" 
  android:gravity="center" 
  android:text="" /> 
 </linearlayout> 
 
 <button 
  android:id="@+id/btn_ok" 
  android:layout_width="wrap_content" 
  android:layout_height="wrap_content" 
  android:background="@drawable/btn_selctor" 
  android:text="保存" /> 
 </linearlayout> 
 
 <scrollview 
 android:layout_width="fill_parent" 
 android:layout_height="fill_parent" 
 android:scrollbars="vertical" > 
 
 <linearlayout 
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent" 
  android:layout_marginleft="2dp" 
  android:orientation="vertical" > 
 
  <edittext 
  android:id="@+id/et_content" 
  android:layout_width="fill_parent" 
  android:layout_height="wrap_content" 
  android:background="#ffae99" 
  android:textsize="20sp" /> 
 </linearlayout> 
 </scrollview> 
 
</linearlayout> 

四、将日志的数据保存在数据库中，使用sqlite来创建数据库，数据库中有三个属性，"_id"、"content"、"date"这三个属性，创建一个notedb来创建数据库。

package com.example.datenote; 
 
import android.content.context; 
import android.database.sqlite.sqlitedatabase; 
import android.database.sqlite.sqliteopenhelper; 
import android.util.log; 
 
public class notesdb extends sqliteopenhelper { 
 
 public static final string table_name_notes = "note"; 
 public static final string column_name_id = "_id"; 
 public static final string column_name_note_content = "content"; 
 public static final string column_name_note_date = "date"; 
 
 public notesdb(context context) { 
 super(context, "note", null, 1); 
 // todo auto-generated constructor stub 
 } 
 
 @override 
 public void oncreate(sqlitedatabase db) { 
 string sql = "create table " + table_name_notes + "(" + column_name_id 
  + " integer primary key autoincrement," 
  + column_name_note_content + " text not null default\"\"," 
  + column_name_note_date + " text not null default\"\"" + ")"; 
 log.d("sql", sql); 
 db.execsql(sql); 
// string sql1="insert into "+table_name_notes+"values("+"1,"+"'写作业',"+"'晚上要写作业的干活'"+")"; 
// log.d("sql1", sql1); 
// db.execsql(sql1); 
// contentvalues values=new contentvalues(); 
// values.put("id",1); 
// values.put("content","写作业"); 
// values.put("date", "2013-1-2"); 
// db.insert("note", null, values); 
 
 } 
 
 @override 
 public void onupgrade(sqlitedatabase arg0, int arg1, int arg2) { 
 // todo auto-generated method stub 
 
 } 
 
} 

五、实现点击添加事件的跳转,在第一个页面中点击添加备忘录后会跳转到第二个界面，设置点击事件，由一个activity跳转到另外一个activity，我使用的是intent方式。另外，在listview中点击每个已记录下来的日志也会跳转到第二个界面，只是显示的不是空白的edittext，而是包含日志的edittext。mainactivity如下：

package com.example.datenote; 
 
import java.util.arraylist; 
import java.util.hashmap; 
import java.util.list; 
import java.util.map; 
 
import android.app.activity; 
import android.app.alertdialog; 
import android.app.alertdialog.builder; 
import android.content.context; 
import android.content.dialoginterface; 
import android.content.intent; 
import android.database.cursor; 
import android.database.sqlite.sqlitedatabase; 
import android.os.bundle; 
import android.util.log; 
import android.view.view; 
import android.view.view.onclicklistener; 
import android.view.window; 
import android.widget.abslistview; 
import android.widget.abslistview.onscrolllistener; 
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 android.widget.toast; 
 
public class mainactivity extends activity implements onscrolllistener, 
 onitemclicklistener, onitemlongclicklistener { 
 
 private context mcontext; 
 private listview listview; 
 private simpleadapter simp_adapter; 
 private list<map<string, object>> datalist; 
 private button addnote; 
 private textview tv_content; 
 private notesdb db; 
 private sqlitedatabase dbread; 
 
 @override 
 protected void oncreate(bundle savedinstancestate) { 
 super.oncreate(savedinstancestate); 
 requestwindowfeature(window.feature_no_title); 
 setcontentview(r.layout.activity_main); 
 tv_content = (textview) findviewbyid(r.id.tv_content); 
 listview = (listview) findviewbyid(r.id.listview); 
 datalist = new arraylist<map<string, object>>(); 
 
 addnote = (button) findviewbyid(r.id.btn_editnote); 
 mcontext = this; 
 addnote.setonclicklistener(new onclicklistener() { 
 
  @override 
  public void onclick(view arg0) { 
  noteedit.enter_state = 0; 
  intent intent = new intent(mcontext, noteedit.class); 
  bundle bundle = new bundle(); 
  bundle.putstring("info", ""); 
  intent.putextras(bundle); 
  startactivityforresult(intent, 1); 
  } 
 }); 
 db = new notesdb(this); 
 dbread = db.getreadabledatabase(); 
 // 清空数据库中表的内容 
 //dbread.execsql("delete from note"); 
 refreshnoteslist(); 
 
 listview.setonitemclicklistener(this); 
 listview.setonitemlongclicklistener(this); 
 listview.setonscrolllistener(this); 
 } 
 
 public void refreshnoteslist() { 
 
 int size = datalist.size(); 
 if (size > 0) { 
  datalist.removeall(datalist); 
  simp_adapter.notifydatasetchanged(); 
  listview.setadapter(simp_adapter); 
 } 
 simp_adapter = new simpleadapter(this, getdata(), r.layout.item, 
  new string[] { "tv_content", "tv_date" }, new int[] { 
   r.id.tv_content, r.id.tv_date }); 
 listview.setadapter(simp_adapter); 
 } 
 
 private list<map<string, object>> getdata() { 
 
 cursor cursor = dbread.query("note", null, "content!=\"\"", null, null, 
  null, null); 
 
 while (cursor.movetonext()) { 
  string name = cursor.getstring(cursor.getcolumnindex("content")); 
  string date = cursor.getstring(cursor.getcolumnindex("date")); 
  map<string, object> map = new hashmap<string, object>(); 
  map.put("tv_content", name); 
  map.put("tv_date", date); 
  datalist.add(map); 
 } 
 cursor.close(); 
 return datalist; 
 
 } 
 
 @override 
 public void onscroll(abslistview arg0, int arg1, int arg2, int arg3) { 
 // todo auto-generated method stub 
 
 } 
 
 // 滑动listview监听事件 
 @override 
 public void onscrollstatechanged(abslistview arg0, int arg1) { 
 // todo auto-generated method stub 
 switch (arg1) { 
 case scroll_state_fling: 
  log.i("main", "用户在手指离开屏幕之前，由于用力的滑了一下，视图能依靠惯性继续滑动"); 
 case scroll_state_idle: 
  log.i("main", "视图已经停止滑动"); 
 case scroll_state_touch_scroll: 
  log.i("main", "手指没有离开屏幕，试图正在滑动"); 
 } 
 } 
 
 // 点击listview中某一项的监听事件 
 @override 
 public void onitemclick(adapterview<?> arg0, view arg1, int arg2, long arg3) { 
 noteedit.enter_state = 1; 
 // log.d("arg2", arg2 + ""); 
 // textview 
 // content=(textview)listview.getchildat(arg2).findviewbyid(r.id.tv_content); 
 // string content1=content.tostring(); 
 string content = listview.getitematposition(arg2) + ""; 
 string content1 = content.substring(content.indexof("=") + 1, 
  content.indexof(",")); 
 log.d("content", content1); 
 cursor c = dbread.query("note", null, 
  "content=" + "'" + content1 + "'", null, null, null, null); 
 while (c.movetonext()) { 
  string no = c.getstring(c.getcolumnindex("_id")); 
  log.d("text", no); 
  // intent intent = new intent(mcontext, noteedit.class); 
  // intent.putextra("data", text); 
  // setresult(4, intent); 
  // // intent.putextra("data",text); 
  // startactivityforresult(intent, 3); 
  intent myintent = new intent(); 
  bundle bundle = new bundle(); 
  bundle.putstring("info", content1); 
  noteedit.id = integer.parseint(no); 
  myintent.putextras(bundle); 
  myintent.setclass(mainactivity.this, noteedit.class); 
  startactivityforresult(myintent, 1); 
 } 
 
 } 
 
 @override 
 // 接受上一个页面返回的数据，并刷新页面 
 protected void onactivityresult(int requestcode, int resultcode, intent data) { 
 // todo auto-generated method stub 
 super.onactivityresult(requestcode, resultcode, data); 
 if (requestcode == 1 && resultcode == 2) { 
  refreshnoteslist(); 
 } 
 } 
 
 // 点击listview中某一项长时间的点击事件 
 @override 
 public boolean onitemlongclick(adapterview<?> arg0, view arg1, int arg2, 
  long arg3) { 
 final int n=arg2; 
 builder builder = new alertdialog.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) { 
  string content = listview.getitematposition(n) + ""; 
  string content1 = content.substring(content.indexof("=") + 1, 
   content.indexof(",")); 
  cursor c = dbread.query("note", null, "content=" + "'" 
   + content1 + "'", null, null, null, null); 
  while (c.movetonext()) { 
   string id = c.getstring(c.getcolumnindex("_id")); 
   string sql_del = "update note set content='' where _id=" 
    + id; 
   dbread.execsql(sql_del); 
   refreshnoteslist(); 
  } 
  } 
 }); 
 builder.setnegativebutton("取消", new dialoginterface.onclicklistener() { 
  @override 
  public void onclick(dialoginterface dialog, int which) { 
  } 
 }); 
 builder.create(); 
 builder.show(); 
 return true; 
 } 
 
} 

六、编写第二个跳转后界面的activity，如下：

package com.example.datenote; 
 
import java.text.simpledateformat; 
import java.util.date; 
 
import android.app.activity; 
import android.content.context; 
import android.content.intent; 
import android.database.sqlite.sqlitedatabase; 
import android.database.sqlite.sqlitestatement; 
import android.os.bundle; 
import android.util.log; 
import android.view.view; 
import android.view.view.onclicklistener; 
import android.view.window; 
import android.view.windowmanager; 
import android.view.inputmethod.inputmethodmanager; 
import android.widget.button; 
import android.widget.edittext; 
import android.widget.textview; 
 
public class noteedit extends activity { 
 private textview tv_date; 
 private edittext et_content; 
 private button btn_ok; 
 private button btn_cancel; 
 private notesdb db; 
 private sqlitedatabase dbread; 
 public static int enter_state = 0; 
 public static string last_content; 
 public static int id; 
 
 @override 
 protected void oncreate(bundle savedinstancestate) { 
 // todo auto-generated method stub 
 super.oncreate(savedinstancestate); 
 // 设置无标题 
 requestwindowfeature(window.feature_no_title); 
 setcontentview(r.layout.edit); 
 
 tv_date = (textview) findviewbyid(r.id.tv_date); 
 date date = new date(); 
 simpledateformat sdf = new simpledateformat("yyyy-mm-dd hh:mm"); 
 string datestring = sdf.format(date); 
 tv_date.settext(datestring); 
 
 et_content = (edittext) findviewbyid(r.id.et_content); 
 // 设置软键盘自动弹出 
 getwindow().setsoftinputmode( 
  windowmanager.layoutparams.soft_input_state_always_visible); 
 
 db = new notesdb(this); 
 dbread = db.getreadabledatabase(); 
 
 bundle mybundle = this.getintent().getextras(); 
 last_content = mybundle.getstring("info"); 
 log.d("last_content", last_content); 
 et_content.settext(last_content); 
 // 确认按钮的点击事件 
 btn_ok = (button) findviewbyid(r.id.btn_ok); 
 btn_ok.setonclicklistener(new onclicklistener() { 
  public void onclick(view arg0) { 
  // 获取日志内容 
  string content = et_content.gettext().tostring(); 
  log.d("log1", content); 
  // 获取写日志时间 
  date date = new date(); 
  simpledateformat sdf = new simpledateformat("yyyy-mm-dd"); 
  string datenum = sdf.format(date); 
  string sql; 
  string sql_count = "select count(*) from note"; 
  sqlitestatement statement = dbread.compilestatement(sql_count); 
  long count = statement.simplequeryforlong(); 
  log.d("count", count + ""); 
  log.d("enter_state", enter_state + ""); 
  // 添加一个新的日志 
  if (enter_state == 0) { 
   if (!content.equals("")) { 
   sql = "insert into " + notesdb.table_name_notes 
    + " values(" + count + "," + "'" + content 
    + "'" + "," + "'" + datenum + "')"; 
   log.d("log", sql); 
   dbread.execsql(sql); 
   } 
  } 
  // 查看并修改一个已有的日志 
  else { 
   log.d("执行命令", "执行了该函数"); 
   string updatesql = "update note set content='" 
    + content + "' where _id=" + id; 
   dbread.execsql(updatesql); 
   // et_content.settext(last_content); 
  } 
  intent data = new intent(); 
  setresult(2, data); 
  finish(); 
  } 
 }); 
 btn_cancel = (button) findviewbyid(r.id.btn_cancel); 
 btn_cancel.setonclicklistener(new onclicklistener() { 
  public void onclick(view arg0) { 
  finish(); 
  } 
 }); 
 } 
 
 @override 
 protected void onactivityresult(int requestcode, int resultcode, intent data) { 
 // todo auto-generated method stub 
 super.onactivityresult(requestcode, resultcode, data); 
 // if (requestcode == 3 && resultcode == 4) { 
 // last_content=data.getstringextra("data"); 
 // log.d("last_straing", last_content+"gvg"); 
 // } 
 } 
} 

七、其中，对listview添加onitemlongclicklistener，长点击之后会弹出一个dialog对话框提醒要不要删除该日志文件。

public boolean onitemlongclick(adapterview<?> arg0, view arg1, int arg2, 
  long arg3) { 
 final int n=arg2; 
 builder builder = new alertdialog.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) { 
  string content = listview.getitematposition(n) + ""; 
  string content1 = content.substring(content.indexof("=") + 1, 
   content.indexof(",")); 
  cursor c = dbread.query("note", null, "content=" + "'" 
   + content1 + "'", null, null, null, null); 
  while (c.movetonext()) { 
   string id = c.getstring(c.getcolumnindex("_id")); 
   string sql_del = "update note set content='' where _id=" 
    + id; 
   dbread.execsql(sql_del); 
   refreshnoteslist(); 
  } 
  } 
 }); 
 builder.setnegativebutton("取消", new dialoginterface.onclicklistener() { 
  @override 
  public void onclick(dialoginterface dialog, int which) { 
  } 
 }); 
 builder.create(); 
 builder.show(); 
 return true; 
 } 

注意最后将返回值设为true，否则会和onitemclicklistener产生冲突。

附上长点击删除的效果。

在结尾附上自己的代码，自己辛苦写的，收取一个资源不多吧，感兴趣的可以下载看看。

下载链接

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