常见布局

线性布局

有一个布局方向，水平或者竖直在竖直布局下，左对齐、右对齐，水平居中生效在水平布局下，顶部对齐、底部对齐、竖直居中生效权重：按比例分配屏幕的剩余宽度或者高度activity_main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" android:orientation="vertical"> <LinearLayout android:layout_weight="1" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="0dp"> <TextView android:text="TextView" android:layout_width="0dp" android:layout_height="match_parent" android:id="@+id/textView4" android:background="@android:color/holo_red_dark" android:layout_weight="1"/> <TextView android:text="TextView" android:layout_width="0dp" android:layout_height="match_parent" android:id="@+id/textView7" android:background="@android:color/holo_orange_dark" android:layout_weight="1"/> <TextView android:text="TextView" android:layout_width="0dp" android:layout_height="match_parent" android:id="@+id/textView6" android:background="@android:color/holo_green_light" android:layout_weight="1"/> <TextView android:text="TextView" android:layout_width="0dp" android:layout_height="match_parent" android:id="@+id/textView5" android:background="@android:color/holo_purple" android:layout_weight="1"/> </LinearLayout> <LinearLayout android:layout_weight="1" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="0dp"> <TextView android:text="TextView" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:background="@android:color/holo_blue_bright" android:id="@+id/textView"/> <TextView android:text="TextView" android:layout_weight="1" android:layout_width="match_parent" android:layout_height="0dp" android:background="@android:color/holo_blue_dark" android:id="@+id/textView8"/> <TextView android:text="TextView" android:layout_weight="1" android:layout_width="match_parent" android:layout_height="0dp" android:background="#78F" android:id="@+id/textView3"/> <TextView android:text="TextView" android:layout_weight="1" android:layout_width="match_parent" android:layout_height="0dp" android:background="@android:color/holo_green_dark" android:id="@+id/textView2"/> </LinearLayout> </LinearLayout>

相对布局

组件默认位置都是左上角，组件之间可以重叠可以相对于父元素上下左右对齐，相对于父元素，水平居中、竖直居中、水平竖直同时居中可以相对于其他组件上下左右对齐可以布局于其他组件的上方、下方、左边、右边 activity_main.xml <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" android:orientation="vertical"> <Button android:text="Center" android:layout_width="wrap_content" android:layout_height="wrap_content"C android:layout_centerInParent="true" android:id="@+id/bt_center"/> <Button android:text="UP" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@+id/bt_center" android:layout_alignLeft="@+id/bt_center" android:layout_alignRight="@+id/bt_center" android:id="@+id/bt_above"/> <Button android:text="DOWN" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/bt_center" android:layout_alignLeft="@+id/bt_center" android:layout_alignRight="@+id/bt_center" android:id="@+id/bt_3"/> <Button android:text="LEFT" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toLeftOf="@id/bt_center" android:layout_alignTop="@id/bt_center" android:layout_alignBottom="@id/bt_center" android:layout_alignParentLeft="true" android:id="@+id/bt_4"/> <Button android:text="左上" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toLeftOf="@id/bt_center" android:layout_above="@id/bt_center" android:layout_alignParentLeft="true" android:id="@+id/bt_6"/> <Button android:text="左下" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toLeftOf="@id/bt_center" android:layout_below="@id/bt_center" android:layout_alignParentLeft="true" android:id="@+id/bt_7"/> <Button android:text="RIGHT" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toRightOf="@id/bt_center" android:layout_alignTop="@id/bt_center" android:layout_alignBottom="@id/bt_center" android:layout_alignParentRight="true" android:id="@+id/bt_5"/> <Button android:text="右上" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toRightOf="@id/bt_center" android:layout_above="@id/bt_center" android:layout_alignParentRight="true" android:id="@+id/bt_8"/> <Button android:text="右上" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toRightOf="@id/bt_center" android:layout_below="@id/bt_center" android:layout_alignParentRight="true" android:id="@+id/bt_9"/> </RelativeLayout>

帧布局

组件默认位置都是左上角，组件之间可以重叠可以设置上下左右对齐，水平竖直居中，设置方式与线性布局一样

activity_main.xml

<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" android:orientation="vertical"> <TextView android:layout_width="240dp" android:layout_height="240dp" android:background="#FF0000" android:layout_gravity="center" /> <TextView android:layout_width="200dp" android:layout_height="200dp" android:background="#00FF00" android:layout_gravity="center" /> <TextView android:layout_width="160dp" android:layout_height="160dp" android:background="#0000FF" android:layout_gravity="center" /> <TextView android:layout_width="120dp" android:layout_height="120dp" android:background="#FFFF00" android:layout_gravity="center" /> <TextView android:layout_width="80dp" android:layout_height="80dp" android:background="#FF00FF" android:layout_gravity="center" /> <TextView android:layout_width="40dp" android:layout_height="40dp" android:background="@android:color/white" android:layout_gravity="center" /> </FrameLayout>

表格布局

每有一个TableRow子节点表示一行，该子节点的每一个子节点都表示一列TableLayout的一级子节点默认宽都是匹配父元素TableRow的子节点默认宽高都是包裹内容 <?xml version="1.0" encoding="utf-8"?> <TableLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:stretchColumns="1" > <TableRow > <TextView android:layout_column="1" android:text="open" /> <TextView android:gravity="right" android:text="Ctrl-O" /> </TableRow> <TableRow > <TextView android:layout_column="1" android:text="save" /> <TextView android:gravity="right" android:text="Ctrl-S" /> </TableRow> <TableRow > <TextView android:text=" " /> <TextView android:text="save AS" /> <TextView android:text="Ctrl-shift-S" /> </TableRow> <TextView android:layout_height="1dp" android:background="#000000" /> <TableRow > <TextView android:text="X" /> <TextView android:layout_span="2" android:text="Import" /> </TableRow> <TableRow > <TextView android:text="X" /> <TextView android:text="Export" /> <TextView android:gravity="right" android:text="Ctrl-E" /> </TableRow> <TextView android:layout_height="1dp" android:background="#000000" /> <TableRow > <TextView android:layout_column="1" android:layout_span="2" android:text="Quit" /> </TableRow> </TableLayout>

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绝对布局少有用武之地，在屏幕分辩率固定的场合下使用

Logcat

等级

verbose：冗余，最低等级debug：调试info：正常等级的信息warn：警告error：错误

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Android的存储

内部存储空间

RAM内存：运行内存，相当于电脑的内存ROM内存：存储内存，相当于电脑的硬盘

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" android:orientation="vertical" > <EditText android:id="@+id/et_name" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入用户名" /> <EditText android:id="@+id/et_pass" android:layout_width="match_parent" android:layout_height="wrap_content" android:inputType="textPassword" android:hint="请输入密码" /> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" > <CheckBox android:id="@+id/cb" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="记住用户名和密码" android:layout_centerVertical="true" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="right" android:text="登录" android:layout_alignParentRight="true" android:onClick="login" /> </RelativeLayout> </LinearLayout>

MainActivity

package com.example.administrator.myapplication; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.CheckBox; import android.widget.EditText; import android.widget.Toast; import java.io.*; public class MainActivity extends AppCompatActivity { private EditText et_name; private EditText et_pass; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); et_name = (EditText) findViewById(R.id.et_name); et_pass = (EditText) findViewById(R.id.et_pass); readAccount(); } public void readAccount(){ File file = new File("data/data/com.example.administrator.myapplication/info.txt"); if(file.exists()){ try { FileInputStream fis = new FileInputStream(file); //把字节流转换成字符流 BufferedReader br = new BufferedReader(new InputStreamReader(fis)); //读取txt文件里的用户名和密码 String text = br.readLine(); String[] s = text.split("##"); et_name.setText(s[0]); et_pass.setText(s[1]); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public void login(View v){ String name = et_name.getText().toString(); String pass = et_pass.getText().toString(); CheckBox cb = (CheckBox) findViewById(R.id.cb); //判断选框是否被勾选 if(cb.isChecked()){ //data/data/com.example.administrator.myapplication:这就是内部存储空间的路径 File file = new File("data/data/com.example.administrator.myapplication/info.txt"); FileOutputStream fos; try { fos = new FileOutputStream(file); fos.write((name + "##" + pass).getBytes()); fos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } //创建并显示吐司对话框 Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show(); } }

//用API获取内部存储文件路径// MainActivity.java

package com.itheima.rwinrom; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.InputStreamReader; import org.apache.http.entity.InputStreamEntity; import com.itheima.apirwinrom.R; import android.os.Bundle; import android.annotation.SuppressLint; import android.app.Activity; import android.view.Menu; import android.view.View; import android.widget.CheckBox; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends Activity { private EditText et_name; private EditText et_pass; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); et_name = (EditText) findViewById(R.id.et_name); et_pass = (EditText) findViewById(R.id.et_pass); readAccount(); } public void readAccount(){ // File file = new File(getFilesDir(), "info.txt"); File file = new File(getCacheDir(), "info.txt"); if(file.exists()){ try { FileInputStream fis = new FileInputStream(file); //把字节流转换成字符流 BufferedReader br = new BufferedReader(new InputStreamReader(fis)); //读取txt文件里的用户名和密码 String text = br.readLine(); String[] s = text.split("##"); et_name.setText(s[0]); et_pass.setText(s[1]); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public void login(View v){ String name = et_name.getText().toString(); String pass = et_pass.getText().toString(); CheckBox cb = (CheckBox) findViewById(R.id.cb); //判断选框是否被勾选 if(cb.isChecked()){ //返回一个File对象，其路径是data/data/com.example.administrator.myapplication/files // File file = new File(getFilesDir(), "info.txt"); //返回值也是一个File对象，其路径是data/data/com.example.administrator.myapplication/cache File file = new File(getCacheDir(), "info.txt"); FileOutputStream fos; try { fos = new FileOutputStream(file); fos.write((name + "##" + pass).getBytes()); fos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } //创建并显示吐司对话框 Toast.makeText(this, "登录成功", 0).show(); } }

外部存储空间

SD卡：相当于电脑的移动硬盘

2.2之前，sd卡路径：sdcard4.3之前，sd卡路径：mnt/sdcard4.3开始，sd卡路径：storage/sdcard

所有存储设备，都会被划分成若干个区块，每个区块有固定的大小

存储设备的总大小 = 区块大小 * 区块数量

在外部存储空间中读取文件

package com.itheima.rwinrom; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.InputStreamReader; import org.apache.http.entity.InputStreamEntity; import com.itheima.rwinsd.R; import android.os.Bundle; import android.os.Environment; import android.annotation.SuppressLint; import android.app.Activity; import android.view.Menu; import android.view.View; import android.widget.CheckBox; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends Activity { private EditText et_name; private EditText et_pass; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); et_name = (EditText) findViewById(R.id.et_name); et_pass = (EditText) findViewById(R.id.et_pass); readAccount(); } public void readAccount(){ if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){ File file = new File("sdcard/info.txt"); if(file.exists()){ try { FileInputStream fis = new FileInputStream(file); //把字节流转换成字符流 BufferedReader br = new BufferedReader(new InputStreamReader(fis)); //读取txt文件里的用户名和密码 String text = br.readLine(); String[] s = text.split("##"); et_name.setText(s[0]); et_pass.setText(s[1]); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } public void login(View v){ String name = et_name.getText().toString(); String pass = et_pass.getText().toString(); CheckBox cb = (CheckBox) findViewById(R.id.cb); //判断选框是否被勾选 if(cb.isChecked()){ //MEDIA_UNKNOWN:不能识别sd卡 //MEDIA_REMOVED:没有sd卡 //MEDIA_UNMOUNTED:sd卡存在但是没有挂载 //MEDIA_CHECKING:sd卡正在准备 //MEDIA_MOUNTED：sd卡已经挂载，可用 if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){ //返回一个File对象，其路径是sd卡的真实路径 File file = new File(Environment.getExternalStorageDirectory(), "info.txt"); // File file = new File("sdcard/info.txt"); FileOutputStream fos; try { fos = new FileOutputStream(file); fos.write((name + "##" + pass).getBytes()); fos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } else{ Toast.makeText(this, "sd卡不可用哟亲么么哒", 0).show(); } } //创建并显示吐司对话框 Toast.makeText(this, "登录成功", 0).show(); } }

获取SD卡剩余容量 MainActivity.java

package com.itheima.getsdavail; import java.io.File; import android.os.Build; import android.os.Bundle; import android.os.Environment; import android.os.StatFs; import android.app.Activity; import android.text.format.Formatter; import android.view.Menu; import android.widget.TextView; public class MainActivity extends Activity { @SuppressWarnings("deprecation") @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); File path = Environment.getExternalStorageDirectory(); StatFs stat = new StatFs(path.getPath()); long blockSize; long totalBlocks; long availableBlocks; //获取当前系统版本的等级 if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2){ blockSize = stat.getBlockSizeLong(); totalBlocks = stat.getBlockCountLong(); availableBlocks = stat.getAvailableBlocksLong(); } else{ blockSize = stat.getBlockSize(); totalBlocks = stat.getBlockCount(); availableBlocks = stat.getAvailableBlocks(); } TextView tv = (TextView) findViewById(R.id.tv); tv.setText(formatSize(availableBlocks * blockSize)); } private String formatSize(long size) { return Formatter.formatFileSize(this, size); } }

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文件访问权限

指的是谁能访问这个文件在Android中，每一个应用，都是一个独立的用户使用10个字母表示drwxrwxrwx第一个字母： d：表示文件夹-：表示文件 第一组rwx：表示的是文件拥有者（owner）对文件的权限 r：read，读w：writex：execute 第二组rwx：表示的是跟文件拥有者属于同一用户组的用户（grouper）对文件的权限第三组rwx：表示的其他用户（other）对文件的权限

代码示例 MainActivity.java

package com.itheima.permission; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import android.os.Bundle; import android.annotation.SuppressLint; import android.app.Activity; import android.view.Menu; import android.view.View; @SuppressLint("WorldReadableFiles") public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void click1(View v){ //路径已经默认为data/data/com.itheima.permission/files try { FileOutputStream fos = openFileOutput("info1.txt", MODE_PRIVATE); fos.write("哈哈哈".getBytes()); fos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void click2(View v){ //路径已经默认为data/data/com.itheima.permission/files try { @SuppressWarnings("deprecation") FileOutputStream fos = openFileOutput("info2.txt", MODE_WORLD_READABLE | MODE_WORLD_WRITEABLE); fos.write("ohohoho".getBytes()); fos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void click3(View v){ //路径已经默认为data/data/com.itheima.permission/files try { @SuppressWarnings("deprecation") FileOutputStream fos = openFileOutput("info3.txt", MODE_WORLD_READABLE | MODE_WORLD_WRITEABLE); fos.write("德玛西亚".getBytes()); fos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

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SharedPreference

非常适合用来保存零散的简单的数据 package com.itheima.rwinrom; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.InputStreamReader; import org.apache.http.entity.InputStreamEntity; import com.itheima.sharedpreference.R; import android.os.Bundle; import android.annotation.SuppressLint; import android.app.Activity; import android.content.SharedPreferences; import android.content.SharedPreferences.Editor; import android.view.Menu; import android.view.View; import android.widget.CheckBox; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends Activity { private EditText et_name; private EditText et_pass; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); et_name = (EditText) findViewById(R.id.et_name); et_pass = (EditText) findViewById(R.id.et_pass); readAccount(); } public void readAccount(){ SharedPreferences sp = getSharedPreferences("info", MODE_PRIVATE); String name = sp.getString("name", ""); String pass = sp.getString("pass", ""); et_name.setText(name); et_pass.setText(pass); } public void login(View v){ String name = et_name.getText().toString(); String pass = et_pass.getText().toString(); CheckBox cb = (CheckBox) findViewById(R.id.cb); //判断选框是否被勾选 if(cb.isChecked()){ //使用sharedPreference来保存用户名和密码 //路径在data/data/com.itheima.sharedpreference/share_ SharedPreferences sp = getSharedPreferences("info", MODE_PRIVATE); //拿到sp的编辑器 Editor ed = sp.edit(); ed.putString("name", name); ed.putString("pass", pass); //提交 ed.commit(); } //创建并显示吐司对话框 Toast.makeText(this, "登录成功", 0).show(); } }

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生成XML文件

备份短信，说白了就是将短信放到一个xml文件中 MainActivity.java

package com.itheima.createxml; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.util.ArrayList; import java.util.List; import com.itheima.createxml.domain.Message; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.view.View; public class MainActivity extends Activity { List<Message> smsList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //虚拟10条短信 smsList = new ArrayList<Message>(); for(int i = 0; i < 10; i++){ Message sms = new Message("小志好棒" + i, System.currentTimeMillis() + "", "138"+i+i, "1"); smsList.add(sms); } } public void click(View v){ //在内存中把xml备份短信的格式拼接出来 StringBuffer sb = new StringBuffer(); sb.append("<?xml version='1.0' encoding='utf-8' standalone='yes' ?>"); sb.append("<messages>"); for (Message sms : smsList) { sb.append("<sms>"); sb.append("<body>"); sb.append(sms.getBody()); sb.append("</body>"); sb.append("<date>"); sb.append(sms.getDate()); sb.append("</date>"); sb.append("<type>"); sb.append(sms.getType()); sb.append("</type>"); sb.append("<address>"); sb.append(sms.getAddress()); sb.append("</address>"); sb.append("</sms>"); } sb.append("</messages>"); File file = new File("sdcard/sms.xml"); try { FileOutputStream fos = new FileOutputStream(file); fos.write(sb.toString().getBytes()); fos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

Message.java

package com.itheima.createxml.domain; public class Message { private String body; private String date; private String address; private String type; public String getBody() { return body; } public void setBody(String body) { this.body = body; } public String getDate() { return date; } public void setDate(String date) { this.date = date; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public String getType() { return type; } public void setType(String type) { this.type = type; } public Message(String body, String date, String address, String type) { super(); this.body = body; this.date = date; this.address = address; this.type = type; } }

用序列化器生成xml文件

MainActivity.java

package com.itheima.xmlserializer; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.xmlpull.v1.XmlSerializer; import com.itheima.createxml.domain.Message; import android.os.Bundle; import android.app.Activity; import android.util.Xml; import android.view.Menu; import android.view.View; public class MainActivity extends Activity { List<Message> smsList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 虚拟10条短信 smsList = new ArrayList<Message>(); for (int i = 0; i < 10; i++) { Message sms = new Message("小志好棒" + i, System.currentTimeMillis() + "", "138" + i + i, "1"); smsList.add(sms); } } public void click(View v){ //使用xml序列化器生成xml文件 //1.拿到序列化器对象 XmlSerializer xs = Xml.newSerializer(); //2.初始化 File file = new File("sdcard/sms2.xml"); try { FileOutputStream fos = new FileOutputStream(file); //enconding:指定用什么编码生成xml文件 xs.setOutput(fos, "utf-8"); //3.开始生成xml文件 //enconding:指定头结点中的enconding属性的值 xs.startDocument("utf-8", true); xs.startTag(null, "message"); for (Message sms : smsList) { xs.startTag(null, "sms"); xs.startTag(null, "body"); xs.text(sms.getBody() + "<body>"); xs.endTag(null, "body"); xs.startTag(null, "date"); xs.text(sms.getDate()); xs.endTag(null, "date"); xs.startTag(null, "type"); xs.text(sms.getType()); xs.endTag(null, "type"); xs.startTag(null, "address"); xs.text(sms.getAddress()); xs.endTag(null, "address"); xs.endTag(null, "sms"); } xs.endTag(null, "message"); //告诉序列化器，文件生成完毕 xs.endDocument(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

pull解析xml文件

weather.xml

<?xml version='1.0' encoding='utf-8' standalone='yes' ?> <weather> <city> <name>上海</name> <temp>5°</temp> <pm>80</pm> </city> <city> <name>北京</name> <temp>-5°</temp> <pm>800</pm> </city> <city> <name>西安</name> <temp>12°</temp> <pm>60</pm> </city> </weather>

City.java

package com.itheima.pullparser.domain; public class City { private String name; private String temp; private String pm; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getTemp() { return temp; } public void setTemp(String temp) { this.temp = temp; } public String getPm() { return pm; } public void setPm(String pm) { this.pm = pm; } @Override public String toString() { return "City [name=" + name + ", temp=" + temp + ", pm=" + pm + "]"; } }

MainActivity.java

package com.itheima.pullparser; import java.io.InputStream; import java.util.ArrayList; import java.util.List; import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import com.itheima.pullparser.domain.City; import android.os.Bundle; import android.app.Activity; import android.util.Xml; import android.view.Menu; import android.view.View; public class MainActivity extends Activity { List<City> cityList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void click(View v){ //获取到src文件夹下的资源文件 InputStream is = getClassLoader().getResourceAsStream("weather.xml"); //拿到pull解析器对象 XmlPullParser xp = Xml.newPullParser(); //初始化 try { xp.setInput(is, "gbk"); //获取当前节点的事件类型，通过事件类型的判断，我们可以知道当前节点是什么节点，从而确定我们应该做什么操作 int type = xp.getEventType(); City city = null; while(type != XmlPullParser.END_DOCUMENT){ //根据节点的类型，要做不同的操作 switch (type) { case XmlPullParser.START_TAG: // 获取当前节点的名字 if("weather".equals(xp.getName())){ //创建city集合对象，用于存放city的javabean cityList = new ArrayList<City>(); } else if("city".equals(xp.getName())){ //创建city的javabean对象 city = new City(); } else if("name".equals(xp.getName())){ // 获取当前节点的下一个节点的文本 String name = xp.nextText(); city.setName(name); } else if("temp".equals(xp.getName())){ // 获取当前节点的下一个节点的文本 String temp = xp.nextText(); city.setTemp(temp); } else if("pm".equals(xp.getName())){ // 获取当前节点的下一个节点的文本 String pm = xp.nextText(); city.setPm(pm); } break; case XmlPullParser.END_TAG: if("city".equals(xp.getName())){ //把city的javabean放入集合中 cityList.add(city); } break; } //把指针移动到下一个节点，并返回该节点的事件类型 type = xp.next(); } for (City c : cityList) { System.out.println(c.toString()); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }