郑京浩崔秀英分手:android sd卡读写 附源码 - 有痣青年 - ITeye技术网站

来源:百度文库 编辑:九乡新闻网 时间:2024/04/28 19:28:41
将文件存在sd卡中和存在手机中的思路相同就是路径不同,注意看类中的到sd卡路径的注释
Java代码  
  1. package cn.lee.data;  
  2.   
  3. import java.io.File;  
  4. import java.io.FileInputStream;  
  5. import java.io.FileOutputStream;  
  6. import java.io.IOException;  
  7.   
  8. import cn.lee.Manager.DataManager;  
  9. import android.app.Activity;  
  10. import android.content.Context;  
  11. import android.os.Bundle;  
  12. import android.os.Environment;  
  13. import android.util.Log;  
  14. import android.view.View;  
  15. import android.view.View.OnClickListener;  
  16. import android.widget.Button;  
  17. import android.widget.EditText;  
  18. import android.widget.Toast;  
  19.   
  20. public class AboutDateActivity extends Activity {  
  21.     private EditText fileNameEditText;  
  22.     private EditText fileContentEditText;  
  23.     private EditText readfileContentEditText;  
  24.     private Button button;  
  25.     private Button readButton;  
  26.     private static final String TAGSTRING = "AboutDateActivity";  
  27.   
  28.     /** Called when the activity is first created. */  
  29.     @Override  
  30.     public void onCreate(Bundle savedInstanceState) {  
  31.         super.onCreate(savedInstanceState);  
  32.         setContentView(R.layout.main);  
  33.   
  34.         button = (Button) this.findViewById(R.id.button);  
  35.         readButton = (Button) this.findViewById(R.id.readButton);  
  36.         fileNameEditText = (EditText) this.findViewById(R.id.fileName);  
  37.         fileContentEditText = (EditText) this.findViewById(R.id.fileContent);  
  38.         readfileContentEditText = (EditText) this  
  39.                 .findViewById(R.id.readfileContent);  
  40.   
  41.         // 读取  
  42.         readButton.setOnClickListener(onClickListener);  
  43.         // 保存  
  44.         button.setOnClickListener(onClickListener);  
  45.     }  
  46.   
  47.     /** 
  48.      * 由于这个内部实现类是一个接口的实例 所以这里把他提取出来 作为一个成员变量 2010-04-18 
  49.      */  
  50.     private View.OnClickListener onClickListener = new View.OnClickListener() {  
  51.         /** 
  52.          * 由于button的父类是view 所以这里的onclick的参数传来的view v就可以找到这个button 
  53.          */  
  54.         public void onClick(View v) {  
  55.             Button button = (Button) v;// 将父类view强转成子类button  
  56.             int info = R.string.sus;  
  57.             String fileNameString = fileNameEditText.getText().toString();  
  58.               
  59.             /** 
  60.              * 判断sd卡是否存在 Environment.getExternalStorageState() 得到sd卡当前的状态 
  61.              *  
  62.              * getExternalStorageState() returns MEDIA_MOUNTED if the 
  63.              * media is present and mounted at its mount point with 
  64.              * read/write access. 如果返回 MEDIA_MOUNTED表示外部存储设备存在。并且有读写的权限(因为sd卡有写保护 如果写保护关闭也是没有权限读写的) 
  65.              */  
  66.               
  67.             if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {  
  68.                 if ("".equals(fileNameString)) {  
  69.                     info = R.string.sdNotExit;  
  70.                 } else {  
  71.                     FileOutputStream fileOutputStream = null;  
  72.                     FileInputStream fileInputStream = null;  
  73.                     try {  
  74.                         /** 
  75.                          * Environment.getExternalStorageDirectory(); 
  76.                          * 得到外存储设备的路径 
  77.                          *  
  78.                          */  
  79.                         File file = new File(Environment.getExternalStorageDirectory(),fileNameString);  
  80.                           
  81.                         switch (button.getId()) {  
  82.                         case R.id.button: {// 保存  
  83.                             String fileContentString = fileContentEditText.getText().toString();  
  84.                               
  85.                             fileOutputStream = new FileOutputStream(file);  
  86.                             DataManager.saveDate(fileOutputStream,fileContentString);  
  87.                             break;  
  88.                         }  
  89.   
  90.                         case R.id.readButton: {//读取  
  91.                             fileInputStream = new FileInputStream(file);  
  92.                             String contentString = DataManager.readDate(fileInputStream);  
  93.                             readfileContentEditText.setText(contentString);  
  94.                             break;  
  95.                         }  
  96.                         default:  
  97.                             break;  
  98.                         }  
  99.   
  100.                     } catch (Exception e) {  
  101.                         // TODO Auto-generated catch block  
  102.                         Log.i(TAGSTRING, e.toString());  
  103.                         info = R.string.infor;  
  104.                     } finally {  
  105.                         try {  
  106.                             if (fileOutputStream != null) {  
  107.                                 fileOutputStream.close();  
  108.                             }  
  109.                             if (fileInputStream != null) {  
  110.                                 fileInputStream.close();  
  111.                             }  
  112.   
  113.                         } catch (IOException e) {  
  114.   
  115.                             Log.i(TAGSTRING, e.toString());  
  116.                             info = R.string.infor;  
  117.                         }  
  118.                     }  
  119.   
  120.                 }  
  121.             } else {  
  122.                 info = R.string.infor;  
  123.             }  
  124.             Toast.makeText(AboutDateActivity.this, info, 1).show();  
  125.         }  
  126.   
  127.     };  
  128. }