19.Android之文件存储方法学习

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical" >
 6 
 7     <TextView
 8         android:id="@+id/filename"
 9         android:layout_width="wrap_content"
10         android:layout_height="20dp"
11         android:textSize="15dp"
12         android:text="文件名称" />
13 
14     <EditText
15         android:id="@+id/edit_name"
16         android:layout_width="match_parent"
17         android:layout_height="wrap_content"/>
18 
19     <TextView
20         android:id="@+id/filecontent"
21         android:layout_width="wrap_content"
22         android:layout_height="20dp"
23         android:textSize="15dp"
24         android:text="文件内容" />
25 
26     <EditText
27         android:id="@+id/edit_content"
28         android:layout_width="match_parent"
29         android:layout_height="wrap_content"/>
30 
31     <LinearLayout
32         android:layout_width="match_parent"
33         android:layout_height="match_parent"
34         android:orientation="horizontal" >
35 
36         <Button
37             android:id="@+id/btn_save"
38             android:layout_width="wrap_content"
39             android:layout_height="wrap_content"
40             android:text="保存文件" />
41 
42         <Button
43             android:id="@+id/btn_read"
44             android:layout_width="wrap_content"
45             android:layout_height="wrap_content"
46             android:text="读取文件" />
47     </LinearLayout>
48 
49 </LinearLayout>

 1 package com.example.filesave;
 2 
 3 import java.io.ByteArrayOutputStream;
 4 import java.io.FileInputStream;
 5 import java.io.FileOutputStream;
 6 
 7 import android.app.Activity;
 8 import android.content.Context;
 9 import android.os.Bundle;
10 import android.view.View;
11 import android.widget.Button;
12 import android.widget.EditText;
13 
14 public class MainActivity extends Activity {
15 
16     private Context context = this;  
17     private Button btnsave = null;
18     private Button btnread = null;
19     private EditText editname = null;
20     private EditText editcontent = null;
21 
22     @Override
23     protected void onCreate(Bundle savedInstanceState) {
24         super.onCreate(savedInstanceState);
25         setContentView(R.layout.activity_main);
26 
27         btnsave = (Button) findViewById(R.id.btn_save);
28         btnread = (Button) findViewById(R.id.btn_read);
29         editname = (EditText) findViewById(R.id.edit_name);
30         editcontent = (EditText) findViewById(R.id.edit_content);
31 
32         btnsave.setOnClickListener(new View.OnClickListener() {
33 
34             @Override
35             public void onClick(View v) {
36 
37                 String filename = editname.getText().toString();
38                 String filecontent = editcontent.getText().toString();
39                 FileOutputStream out = null;
40                 try {
41                     out = context
42                             .openFileOutput(filename, Context.MODE_PRIVATE);
43                     out.write(filecontent.getBytes("UTF-8"));
44                     
45                     editname.setText("已经保存名称!");
46                     editcontent.setText("已经保存内容!");
47                     
48                 } catch (Exception e) {
49                     e.printStackTrace();
50                 } finally {
51                     try {
52                         out.close();
53                     } catch (Exception e) {
54                         e.printStackTrace();
55                     }
56                 }
57             }
58         });
59 
60         btnread.setOnClickListener(new View.OnClickListener() {
61 
62             @Override
63             public void onClick(View v) {
64                 String filename = editname.getText().toString(); // 获得读取的文件的名称
65                 FileInputStream in = null;
66                 ByteArrayOutputStream bout = null;
67                 byte[] buf = new byte[1024];
68                 bout = new ByteArrayOutputStream();
69                 int length = 0;
70                 try {
71                     in = context.openFileInput(filename); // 获得输入流
72                     while ((length = in.read(buf)) != -1) {
73                         bout.write(buf, 0, length);
74                     }
75                     byte[] content = bout.toByteArray();
76                     editcontent.setText(new String(content, "UTF-8")); // 设置文本框为读取的内容
77                 } catch (Exception e) {
78                     e.printStackTrace();
79                 }
80                 editcontent.invalidate(); // 刷新屏幕
81                 try {
82                     in.close();
83                     bout.close();
84                 } catch (Exception e) {
85                 }
86             }
87      
88 
89         });
90 
91     }
92 
93 }