使用DOM模式将界面内容转换为XML

首先，需要在项目的AndroidManifest.xml文件中添加对外部存储的写入权限，确保应用能够访问并写入外部存储设备。

1 
2 
3 4     android:allowBackup="true"
5     android:icon="@drawable/ic_launcher"
6     android:label="@string/app_name"
7     android:theme="@style/AppTheme" >
8     9         android:name="com.example.androidfilestream04.MainActivity"
10        android:label="@string/app_name" >
11        
12            
13            
14        
15    
16 

接下来，设计用户界面，通过TableLayout布局来创建一个简单的表单，包含姓名和邮箱的输入框以及一个提交按钮。

1 2     xmlns:tools="http://schemas.android.com/tools"
3     android:id="@+id/TableLayout1"
4     android:layout_width="match_parent"
5     android:layout_height="match_parent" >
6 
7     
8 
9         10            android:layout_width="wrap_content"
11            android:layout_height="wrap_content"
12            android:text="姓名" />
13 
14         15            android:id="@+id/name"
16            android:layout_width="match_parent"
17            android:layout_height="wrap_content" />
18     
19 
20     
21 
22         23            android:layout_width="wrap_content"
24            android:layout_height="wrap_content"
25            android:text="邮箱" />
26 
27         28            android:id="@+id/email"
29            android:layout_width="match_parent"
30            android:layout_height="wrap_content" />
31     
32 
33     
34 
35         36            android:id="@+id/but"
37            android:layout_width="wrap_content"
38            android:layout_height="wrap_content"
39            android:text="提交" />
40     
41 

最后，在MainActivity中实现逻辑处理，当用户点击提交按钮时，应用会检查外部存储是否可用，并将用户输入的信息以XML格式保存到指定的文件中。

 1 package com.example.androidfilestream04;
 2 
 3 import java.io.File;
 4 import java.io.StringWriter;
 5 import javax.xml.parsers.DocumentBuilder;
 6 import javax.xml.parsers.DocumentBuilderFactory;
 7 import javax.xml.parsers.ParserConfigurationException;
 8 import javax.xml.transform.OutputKeys;
 9 import javax.xml.transform.Result;
10 import javax.xml.transform.Source;
11 import javax.xml.transform.Transformer;
12 import javax.xml.transform.TransformerConfigurationException;
13 import javax.xml.transform.TransformerException;
14 import javax.xml.transform.TransformerFactory;
15 import javax.xml.transform.dom.DOMSource;
16 import javax.xml.transform.stream.StreamResult;
17 import org.w3c.dom.Document;
18 import org.w3c.dom.Element;
19 import android.os.Bundle;
20 import android.os.Environment;
21 import android.app.Activity;
22 import android.view.Menu;
23 import android.view.View;
24 import android.view.View.OnClickListener;
25 import android.widget.Button;
26 import android.widget.EditText;
27 
28 public class MainActivity extends Activity {
29     private EditText name;
30     private EditText email;
31     private Button but = null;
32 
33     @Override
34     protected void onCreate(Bundle savedInstanceState) {
35         super.onCreate(savedInstanceState);
36         setContentView(R.layout.activity_main);
37         this.name = (EditText) findViewById(R.id.name);
38         this.email = (EditText) findViewById(R.id.email);
39         this.but = (Button) findViewById(R.id.but);
40         this.but.setOnClickListener(new OnClickListenerImpl());
41     }
42 
43     private class OnClickListenerImpl implements OnClickListener {
44 
45         @Override
46         public void onClick(View v) {
47             if (!Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
48                 return;
49             }
50             File file = new File(Environment.getExternalStorageDirectory() + File.separator + "neusoft" + File.separator + "member1.xml");
51             if (!file.getParentFile().exists()) {
52                 file.getParentFile().mkdirs();
53             }
54             DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
55             DocumentBuilder builder = null;
56             try {
57                 builder = factory.newDocumentBuilder();
58             } catch (ParserConfigurationException e) {
59                 e.printStackTrace();
60             }
61             Document doc = null;
62             doc = builder.newDocument();
63             Element addresslist = doc.createElement("addresslist");
64             Element linkman = doc.createElement("linkman");
65             Element name = doc.createElement("name");
66             Element email = doc.createElement("email");
67             name.appendChild(doc.createTextNode(MainActivity.this.name.getText().toString()));
68             email.appendChild(doc.createTextNode(MainActivity.this.email.getText().toString()));
69             linkman.appendChild(name);
70             linkman.appendChild(email);
71             addresslist.appendChild(linkman);
72             doc.appendChild(addresslist);
73             TransformerFactory tf = TransformerFactory.newInstance();
74             Transformer t = null;
75             try {
76                 t = tf.newTransformer();
77             } catch (TransformerConfigurationException e) {
78                 e.printStackTrace();
79             }
80             t.setOutputProperty(OutputKeys.ENCODING, "utf-8");
81             DOMSource source = new DOMSource(doc);
82             StreamResult result = new StreamResult(file);
83             try {
84                 t.transform(source, result);
85             } catch (TransformerException e) {
86                 e.printStackTrace();
87             }
88         }
89     }
90 }