android 文件的读取与写入以及TextView的滚动

package training.android.com;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ScrollView;
import android.widget.TextView;
import android.widget.Toast;

public class fileWriteRead extends Activity implements OnClickListener {
	/** Called when the activity is first created. */
	private EditText edit_Text;// 编缉文本框
	private Button btn_Save;// 保相聚按钮
	private String text_of_input;// 输入文本值
	private OutputStream os;// 输出流
	private TextView showMyText;// 显示文本
	private Button btnOpenText, btnCleanText;// 打开与清空按钮事件
	private Button btnOpenRaw;
	private String Text_of_output;// 输入出文本
	private InputStream is;// 输入流
	private InputStream iputRaw;//静态文件流
	private byte[] b;
	private ScrollView scroll;
	private int ori=0;
	/**
	 * 页面的初始化
	 * 
	 */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		// setContentView(R.layout.main);
		showLayout("main");
		UIinit("main");
		Logic("main");
	}

	/**
	 * 通过页面名称去显示各页面信息 创建人：周昕 创建时间：2010-4-8 方法名称：showLayout
	 * 
	 * @param layoutName
	 */
	private void showLayout(String layoutName) {
		if (layoutName.equals("main")) {
			setContentView(R.layout.main);
		}
		if (layoutName.equals("openfile")) {
			setContentView(R.layout.openfile);
		}

	}

	/**
	 * 通过页面名称去初始化控件
	 * 
	 * @param uiName
	 *            创建人：周昕 &&&&&&&& 创建时间：2010-4-8
	 */
	private void UIinit(String uiName) {
		if (uiName.equals("main")) {
			edit_Text = (EditText) findViewById(R.id.Edit_text);
			btn_Save = (Button) findViewById(R.id.Button_save);
		}
		if (uiName.equals("openfile")) {
			btnOpenText = (Button) findViewById(R.id.Button_openTxt);
			btnCleanText = (Button) findViewById(R.id.Button_clean);
			btnOpenRaw = (Button) findViewById(R.id.Button_openRaw);
			showMyText = (TextView) findViewById(R.id.TextView_showTxt);
		}
	}

	/**
	 * 通过页面名称去对各Button指定事件
	 * 
	 * @param pageName
	 *            创建人：周昕******** 创建时间：2010-4-8
	 */
	private void Logic(String pageName) {
		if (pageName.equals("main")) {
			btn_Save.setOnClickListener(this);
		}
		if (pageName.equals("openfile")) {
			btnOpenText.setOnClickListener(this);
			btnCleanText.setOnClickListener(this);
			btnOpenRaw.setOnClickListener(this);
		}
	}

	/**
	 * 在Toast中显示指定的字段
	 * 
	 * @param strTitle
	 */
	private void NoteDebug(String strTitle) {
		Toast.makeText(this, strTitle, Toast.LENGTH_SHORT).show();
	}

	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		switch (v.getId()) {
		case R.id.Button_save:
			NoteDebug("文件保存");
			text_of_input = edit_Text.getText().toString();
			try {
				os = this.openFileOutput("txtME", MODE_PRIVATE);
				os.write(text_of_input.getBytes());
			} catch (FileNotFoundException e) {
				NoteDebug("文件关闭失败" + e);
			} catch (IOException e) {
				NoteDebug("文件写入失败" + e);
			} finally {
				try {
					os.close();
				} catch (IOException e) {
					NoteDebug("关闭文件失败" + e);
				}
			}
			edit_Text.setText("");
			break;
		case R.id.Button_openTxt:
			NoteDebug("打开文件");
			try {
				is = this.openFileInput("txtME");
				b = new byte[1024];
				int length = is.read(b);
				Text_of_output = new String(b);
				setTitle("文件字数" + length);
				showMyText.setText(Text_of_output);
			} catch (FileNotFoundException e) {
				NoteDebug("文件打开失败" + e);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				NoteDebug("文件读取失败" + e);
			} finally {
				try {
					is.close();
				} catch (IOException e) {
					NoteDebug("文件关闭失败" + e);
				}
			}
			break;
		case R.id.Button_openRaw:
			NoteDebug("打开静态文件");
			try {
				iputRaw = this.getResources().openRawResource(R.raw.filetext);
				b = new byte[102400];
				int length = iputRaw.read(b);
				Text_of_output="";
				Text_of_output = new String(b);
				setTitle("静态文件字数" + length);
				showMyText.setText(Text_of_output);
				showMyText.setHorizontallyScrolling(true);
				scroll = (ScrollView)findViewById(R.id.scroll);    
		        scroll.smoothScrollBy(ori, 0);

			} catch (FileNotFoundException e) {
				NoteDebug("静态文件打开失败" + e);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				NoteDebug("静态文件读取失败" + e);
			} finally {
				try {
					iputRaw.close();
				} catch (IOException e) {
					NoteDebug("静态文件关闭失败" + e);
				}
			}
			break;
		case R.id.Button_clean:
			NoteDebug("清空文件");
			showMyText.setText("");
			NoteDebug("清空");
			break;
		}

	}

	public boolean onCreateOptionsMenu(Menu menu) {
		menu.add(0, 1, 1, "edit");
		menu.add(0, 2, 2, "open");
		menu.add(0, 3, 3, "clear");
		return super.onCreateOptionsMenu(menu);
	}

	public boolean onOptionsItemSelected(MenuItem items) {
		switch (items.getItemId()) {
		case 1:
			showLayout("main");
			UIinit("main");
			Logic("main");
			NoteDebug("编缉文件");
			break;
		case 2:
			showLayout("openfile");
			UIinit("openfile");
			Logic("openfile");
			NoteDebug("打开件");
			break;
		case 3:
			showLayout("openfile");
			UIinit("openfile");
			Logic("openfile");
			NoteDebug("清空文件");
			break;
		}
		return super.onOptionsItemSelected(items);
	}
	
	 private Handler message = new Handler(){
	    	public void handleMessage(Message msg) {
	    		doScrow();
					
				}
		};
			
	    public class TimerLoop implements Runnable {
			@Override
			public void run() {
				// TODO Auto-generated method stub
				
				while(true){
					loop(500);
					
					message.sendEmptyMessage(0);
				}
			}
	    	
	    }
	    
	//因为sleep()似乎不好用 所以采用这种方法计时
	    public void loop(long i){
	    	long j = i;
	    	while(j>0){
	    		
	    		j = j-1;
			}

	    }
	    public boolean onKeyDown(int keyCode, KeyEvent msg){
//	    	Thread loop = new Thread(new TimerLoop());
//	    	loop.start();
	    	
	    	return super.onKeyDown(keyCode, msg);
		}
	    public void doScrow(){
	    	int now = scroll.getScrollY();
	    	
	    	if(ori == now){
	    		scroll.scrollTo(now, 0);
	    		ori = -1;
	    		
	    	}
	    	else {
	    		scroll.smoothScrollBy(10, 10);
	    		
	    		ori = now;
	    		
	    	}
	    }
}

main.xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

<EditText 
         android:id="@+id/Edit_text" 
         android:layout_width="fill_parent" 
         android:layout_height="350px">
         </EditText>
<Button 
       android:text="保存" 
       android:id="@+id/Button_save" 
       android:layout_width="80px" 
       android:layout_height="wrap_content">
       </Button>
</LinearLayout>

open.xml

<?xml version="1.0" encoding="UTF-8"?>
<AbsoluteLayout android:id="@+id/openlayout"
	android:layout_width="fill_parent" android:layout_height="fill_parent"
	xmlns:android="http://schemas.android.com/apk/res/android">
	<!-- <ScrollView android:layout_weight="1" android:layout_width="fill_parent"
		android:layout_height="wrap_content" android:scrollbars="vertical"
		android:fadingEdge="vertical" android:id="@+id/scroll">
		 -->
		 <ScrollView 
	android:id="@+id/scroll"
	android:layout_width="fill_parent" 
    android:layout_height="300dip" >
		<LinearLayout android:layout_width="fill_parent"
			android:layout_height="380px">
			<TextView android:id="@+id/TextView_showTxt"
				android:layout_width="314px" android:layout_height="373px"
				  android:scrollbars="vertical" android:fadingEdge="vertical"
				
				android:autoText="true" android:layout_x="3px" android:layout_y="3px"
				>
				<!-- android:ellipsize="marquee" android:marqueeRepeatLimit="marquee_forever" -->
			</TextView>
		</LinearLayout>
	</ScrollView>
	
	<Button android:id="@+id/Button_openTxt" android:layout_width="80px"
		android:layout_height="wrap_content" android:text="打开"
		android:layout_x="2px" android:layout_y="378px">
	</Button>
	<Button android:id="@+id/Button_openRaw" android:layout_width="80px"
		android:layout_height="wrap_content" android:text="静态文件"
		android:layout_x="102px" android:layout_y="378px">
	</Button>
	<Button android:id="@+id/Button_clean" android:layout_width="80px"
		android:layout_height="wrap_content" android:text="清空"
		android:layout_x="239px" android:layout_y="378px">
	</Button>
</AbsoluteLayout>

AndroidMainfest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
	package="training.android.com" android:versionCode="1"
	android:versionName="1.0">
	<application android:icon="@drawable/icon" android:label="@string/app_name">
		<activity android:name=".fileWriteRead" android:label="@string/app_name">
			<intent-filter>
				<action android:name="android.intent.action.MAIN" />
				<category android:name="android.intent.category.LAUNCHER" />
			</intent-filter>
		</activity>

	</application>
	<uses-sdk android:minSdkVersion="3" />
	<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
	<uses-permission android:name="android.permission.MODE_WORLD_READABLE"></uses-permission>
	<uses-permission android:name="android.permission.MODE_WORLD_WRITEABLE"></uses-permission>
</manifest>