【android开发】android操作文件

目的：打开文件，查看文件内容，情况内容，追加内容。

1.创建android project

2.activity内容：

package com.android;

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.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.TextView;
import android.widget.Toast;

public class Activity12 extends Activity implements OnClickListener{

	private EditText inputEt;//编辑框
	private Button saveBtn;//保存 按钮
	private String input_text;//输入的字符串
	private OutputStream os;
	
	private TextView showText; //显示读取的内容
	private Button openTxtBtn; //open file button
	private Button cleanTxtBtn;//clean file
	private String text_output; 
	private InputStream is;
	private byte[] b;
	
	private final String FILE = "filetext.txt";
	
	
	@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.show);
    }
	
	/**
	 * 设置显示view
	 * @param layoutId
	 */
	private void setLayout(int layoutId) {
		setContentView(layoutId);
	}
	
	/**
	 * 各种布局下，得到view
	 * @param mainOpen
	 */
	private void initUI(String mainOpen) {
		if (mainOpen.equals("main")) {
			inputEt = (EditText)findViewById(R.id.edit_txt);
			saveBtn = (Button)findViewById(R.id.save);
		} else if (mainOpen.equals("open")) {
			showText = (TextView)findViewById(R.id.showTxt);
			openTxtBtn = (Button)findViewById(R.id.openTxtB);
			cleanTxtBtn = (Button)findViewById(R.id.cleanBtn);
		}
	}

	/**
	 * 不同布局下添加自己的Event
	 * @param str
	 */
	private void addEvent(String str) {
		if (str.equals("main")) {
			saveBtn.setOnClickListener(this);
		} else if (str.equals("open")) {
			openTxtBtn.setOnClickListener(this);
			cleanTxtBtn.setOnClickListener(this);
		}
	}
	
	/* (non-Javadoc)
	 * @see android.view.View.OnClickListener#onClick(android.view.View)
	 */
	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		switch (v.getId()) {
		case R.id.save:{
			input_text = inputEt.getText().toString();
			try {
				os = this.openFileOutput(FILE, MODE_PRIVATE);
				os.write(input_text.getBytes());
			} catch(FileNotFoundException e) {
				toast(getString(R.string.fileCloseError) + e);
			} catch(IOException e) {
				toast("文件写入失败" + e);
			} finally {
				try {
					os.close();
				} catch(Exception e) {
					toast(getString(R.string.fileCloseError) + e);
				}
			}
			inputEt.setText("");
			toast("文件保存成功!!!查看请点击Menu");
		}
		break;
		case R.id.openTxtB: {
			toast("文件打开");
			try {
				
				is = this.openFileInput(FILE);
				//is = getResources().openRawResource(R.raw.filetext);
				b = new byte[1024];
				int length = is.read(b);
				text_output = new String(b);
				setTitle("文件字数 " + length);
				showText.setText(text_output);
			} catch(FileNotFoundException e) {
				toast("文件打开失败" + e);
			} catch(IOException e) {
				toast("文件读取失败" + e);
			} finally {
				try {
					is.close();
				} catch(Exception e) {
					toast(getString(R.string.fileCloseError) + e);
				}
			}
		}
		break;
		case R.id.cleanBtn: {
			showText.setText("");
			toast(getString(R.string.clean));
		}
		break;
		default:
			break;
		}
	}

	/* 增加menu
	 * @see android.app.Activity#onCreateOptionsMenu(android.view.Menu)
	 */
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// TODO Auto-generated method stub
		
		menu.add(0, 1, 1, "Edit").setIcon(R.drawable.edit);
		menu.add(0, 2, 2, "Open").setIcon(R.drawable.open);
		menu.add(0, 3, 3, "Exit").setIcon(R.drawable.exit);
		return super.onCreateOptionsMenu(menu);
	}

	/* 点击menu item
	 * @see android.app.Activity#onOptionsItemSelected(android.view.MenuItem)
	 */
	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		// TODO Auto-generated method stub
		switch (item.getItemId()) {
		case 1: 
			setLayout(R.layout.main);
			initUI("main");
			addEvent("main");
			setTitle("请输入追加的内容：");
			toast("编辑文件");
			break;
		case 2:
			setLayout(R.layout.open);
			initUI("open");
			addEvent("open");
			toast("打开文件");
			break;
		case 3:
			finish();
			toast("Byebye");
			break;
		default:
			break;
		}
		
		return super.onOptionsItemSelected(item);
		
	}
	
	/**
	 * 提示
	 * @param str 内容
	 */
	private void toast(String str) {
		Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
	}
	
	
	
    
}

  3.布局文件

main.xml 追加文件内容填写页，一个editText 一个button

<?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"
    android:background="@color/hui"
    >
<EditText  
	android:id="@+id/edit_txt"
    android:layout_width="350px" 
    android:layout_height="350px" 
    />
<Button
	android:layout_height="wrap_content"
	android:id="@+id/save"
	android:text="保存"
	android:layout_width="80px"
/>
</LinearLayout>

 show.xml 首页

<?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"
    android:background="@color/hui"
    >
    <TextView  
	android:id="@+id/ss"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"
    android:textSize="30px"
    android:text="粗糙文件编辑,请点击Menu" 
    />
</LinearLayout>

  open.xml 操作文件

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/openlayout"
    android:background="@color/hui"
    >
<TextView  
	android:id="@+id/showTxt"
    android:layout_width="314px" 
    android:layout_height="373px" 
	android:layout_x="3px"
	android:layout_y="3px"
    />
<Button
	android:layout_height="wrap_content"
	android:id="@+id/openTxtB"
	android:text="打开"
	android:layout_width="80px"
	android:layout_x="2px"
	android:layout_y="378px"
/>
<Button
	android:layout_height="wrap_content"
	android:id="@+id/cleanBtn"
	android:text="清空"
	android:layout_width="80px"
	android:layout_x="239px"
	android:layout_y="378px"
/>
</AbsoluteLayout>

 4.string.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">12</string>
    <string name="fileCloseError">文件关闭失败</string>
    <string name="clean">清空</string>
    <color name = "hui">#FFFACD</color>
</resources>

 结果：

首页

 点menu

点open

点edit

点exit

 

明天继续完善。美化。。。。

byebye!!!