Android（java）学习笔记184：生成4种模式的文件

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     tools:context=".MainActivity" >
 6 
 7     <Button
 8         android:onClick="click"
 9         android:layout_width="wrap_content"
10         android:layout_height="wrap_content"
11         android:layout_centerHorizontal="true"
12         android:layout_centerVertical="true"
13         android:text="生成文件" />
14 
15     <RadioGroup
16         android:id="@+id/rg_mode"
17         android:layout_width="wrap_content"
18         android:layout_height="wrap_content" >
19 
20         <RadioButton
21             android:id="@+id/rb_private"
22             android:layout_width="wrap_content"
23             android:layout_height="wrap_content"
24             android:checked="true"
25             android:text="私有 private" />
26 
27         <RadioButton
28             android:id="@+id/rb_readble"
29             android:layout_width="wrap_content"
30             android:layout_height="wrap_content"
31             android:text="全局可读 world readable" />
32 
33         <RadioButton
34             android:id="@+id/rb_writeable"
35             android:layout_width="wrap_content"
36             android:layout_height="wrap_content"
37             android:text="全局可写world writeable" />
38 
39         <RadioButton
40             android:id="@+id/rb_public"
41             android:layout_width="wrap_content"
42             android:layout_height="wrap_content"
43             android:text="全局可读可写public" />
44     </RadioGroup>
45 
46 </RelativeLayout>

 1 package com.itheima.filemode;
 2 
 3 import java.io.FileOutputStream;
 4 
 5 import android.app.Activity;
 6 import android.os.Bundle;
 7 import android.view.View;
 8 import android.widget.RadioGroup;
 9 
10 public class MainActivity extends Activity {
11     private RadioGroup rg_mode;
12 
13     @Override
14     protected void onCreate(Bundle savedInstanceState) {
15         super.onCreate(savedInstanceState);
16         setContentView(R.layout.activity_main);
17         rg_mode = (RadioGroup) findViewById(R.id.rg_mode);
18     }
19 
20     /**
21      * 按钮的点击事件
22      * 
23      * @param view
24      */
25     public void click(View view) {
26         try {
27             int id = rg_mode.getCheckedRadioButtonId();
28             FileOutputStream fos = null;
29             switch (id) {
30             case R.id.rb_private:// 私有文件
31                 fos = openFileOutput("private.txt",  MODE_PRIVATE);
32                 break;
33             case R.id.rb_public:// 可读可写文件
34                 fos = openFileOutput("public.txt",  MODE_WORLD_READABLE+MODE_WORLD_WRITEABLE);
35                 break;
36             case R.id.rb_readble:// 全局可读文件
37                 fos = openFileOutput("readble.txt",  MODE_WORLD_READABLE);
38                 break;
39             case R.id.rb_writeable:// 全局可写文件
40                 fos = openFileOutput("/sdcard/files/writeable.txt",  MODE_WORLD_WRITEABLE);
41                 break;
42             }
43             fos.write("dfafda".getBytes());
44             fos.close();
45         } catch (Exception e) {
46             e.printStackTrace();
47         }
48     }
49 }