黎活明8天快速掌握android视频教程14_把文件存放在SDCard

package&＃61;"contract.test.savafileapplication" ><applicationandroid:allowBackup&＃61;"true"android:icon&＃61;"&＃64;drawable/ic_launcher"android:label&＃61;"&＃64;string/app_name"android:theme&＃61;"&＃64;style/AppTheme" ><activityandroid:name&＃61;".MyActivity"android:label&＃61;"&＃64;string/app_name" >

package contract.test.savafileapplication;import android.content.Context;
import android.os.Environment;import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class FileService {private Context context;public FileService(Context context) {this.context &＃61; context;}public void saveTosdCard(String fileName, String fileContext) throws Exception {File file &＃61; new File(Environment.getExternalStorageDirectory(),fileName);FileOutputStream fileOutputStream &＃61; new FileOutputStream(file);fileOutputStream.write(fileContext.getBytes());fileOutputStream.close();}public String readFromSdCard(String filename) throws IOException{File file &＃61; new File(Environment.getExternalStorageDirectory(),filename);FileInputStream fileInputStream &＃61; new FileInputStream(file);byte[] bytes &＃61; new byte[1024];ByteArrayOutputStream byteArrayOutputStream &＃61; new ByteArrayOutputStream();/*byte是基本数据类型 如int类型Byte是byte的包装类*/int len &＃61; 0;while ((len &＃61; fileInputStream.read(bytes))!&＃61;-1){byteArrayOutputStream.write(bytes,0,len);}byteArrayOutputStream.close();fileInputStream.close();String str &＃61; new String(byteArrayOutputStream.toString());return str;}
}

package contract.test.savafileapplication;import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;import java.io.IOException;public class MyActivity extends Activity {private Button save , show;private EditText filename, filecontext;private TextView showContext;&＃64;Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_my);save &＃61; (Button)this.findViewById(R.id.saveButton);show &＃61; (Button)this.findViewById(R.id.showButton);filename &＃61; (EditText)this.findViewById(R.id.fileName_ET);filecontext &＃61; (EditText)this.findViewById(R.id.saveContext_ET);showContext &＃61; (TextView)this.findViewById(R.id.showConTextView);save.setOnClickListener(new View.OnClickListener() {&＃64;Overridepublic void onClick(View v) {String name &＃61; filename.getText().toString();String context &＃61; filecontext.getText().toString();FileService fileService &＃61; new FileService(getApplicationContext());try {if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){fileService.saveTosdCard(name,context);Toast.makeText(getApplicationContext(),"文件保存成功&＃xff01;",Toast.LENGTH_LONG).show();}else{Toast.makeText(getApplicationContext(),"sdCard不存在或者写保护&＃xff01;",Toast.LENGTH_LONG).show();}} catch (Exception e) {Toast.makeText(getApplicationContext(),"文件保存失败&＃xff01;",Toast.LENGTH_LONG).show();e.printStackTrace();}}});show.setOnClickListener(new View.OnClickListener() {&＃64;Overridepublic void onClick(View v) {FileService fileService &＃61; new FileService(getApplicationContext());String name &＃61; filename.getText().toString();try {if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){String str &＃61; fileService.readFromSdCard(name);Toast.makeText(getApplicationContext(),"文件读取成功&＃xff01;",Toast.LENGTH_LONG).show();showContext.setText(str);}else{Toast.makeText(getApplicationContext(),"sdCard不存在或者写保护&＃xff01;",Toast.LENGTH_LONG).show();}} catch (IOException e) {e.printStackTrace();Toast.makeText(getApplicationContext(),"文件读取失败&＃xff01;",Toast.LENGTH_LONG).show();}}});}&＃64;Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.my, menu);return true;}&＃64;Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id &＃61; item.getItemId();if (id &＃61;&＃61; R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}
}

xml version&＃61;"1.0" encoding&＃61;"utf-8"?>
<LinearLayout xmlns:android&＃61;"http://schemas.android.com/apk/res/android"android:orientation&＃61;"vertical"android:layout_width&＃61;"fill_parent"android:layout_height&＃61;"fill_parent"><TextViewandroid:layout_width&＃61;"fill_parent"android:layout_height&＃61;"wrap_content"android:text&＃61;"请输入要保存的文件名:"/><EditTextandroid:id&＃61;"&＃64;&＃43;id/fileName_ET"android:layout_width&＃61;"fill_parent"android:layout_height&＃61;"50dp"android:hint&＃61;"请输入要保存的文件名&＃xff01;"/><TextViewandroid:layout_width&＃61;"fill_parent"android:layout_height&＃61;"wrap_content"android:text&＃61;"请您输入要保存的内容&＃xff1a;"/><EditTextandroid:id&＃61;"&＃64;&＃43;id/saveContext_ET"android:layout_width&＃61;"fill_parent"android:layout_height&＃61;"wrap_content"android:hint&＃61;"请您在此处输入文件内容&＃xff01;"/><Buttonandroid:id&＃61;"&＃64;&＃43;id/saveButton"android:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:text&＃61;"save"/><Buttonandroid:id&＃61;"&＃64;&＃43;id/showButton"android:layout_width&＃61;"wrap_content"android:layout_height&＃61;"wrap_content"android:text&＃61;"show"/><TextViewandroid:id&＃61;"&＃64;&＃43;id/showConTextView"android:layout_width&＃61;"fill_parent"android:layout_height&＃61;"wrap_content"/>
LinearLayout>