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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