从零开始学android<数据存储（2）Internal Storage内部存储.三十六.>

2022-10-06 12:56:24

Call openFileOutput() with the name of the file and the operating mode. This returns a FileOutputStream.通过 openFileOutput()建立FileoutputStream对象
Write to the file with write().创建Write对象并进行数据读写操作
Close the stream with close().最后关闭链接

以上就是讲数据文件保存到内部储存的基本步骤

下面用代码进行一下讲解

xml文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button1"
        android:layout_alignBottom="@+id/button1"
        android:layout_marginLeft="51dp"
        android:layout_toRightOf="@+id/button1"
        android:text="读取信息" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="31dp"
        android:layout_marginTop="142dp"
        android:text="保存信息" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="47dp"
        android:text="保存数据到内部储存"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

ＪＡＶＡ文件

package com.example.internalstorage;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
	private Button saveData, getData;
	private static final String FILENAME = "flyou.txt";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		saveData=(Button)this.findViewById(R.id.button1);
		getData=(Button)this.findViewById(R.id.button2);
		saveData.setOnClickListener(new View.OnClickListener() {／／保存信息
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				FileOutputStream out = null;
				try {
					String infoString = "风飞雪未扬";
					out = openFileOutput(FILENAME, Context.MODE_PRIVATE);
					out.write(infoString.getBytes());
					Toast.makeText(MainActivity.this, "数据保存成功", 2).show();
				} catch (FileNotFoundException e) {
					e.printStackTrace();
				} catch (IOException e) {
					e.printStackTrace();
				}

				finally {
					try {
						if (out!=null) {
						
							out.close();	
						}
						
					} catch (IOException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}	
			}
		});
		
//		读取信息
		
		getData.setOnClickListener(new View.OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
			FileInputStream input=null;
			try {
				input=openFileInput(FILENAME);
				byte[] data=new byte[1024];
				int len=input.read(data);
				input.close();
//				System.out.println(new String(data,0,len));
				Toast.makeText(MainActivity.this, new String(data,0,len), 2).show();
			} catch (FileNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
				
			}
		});
	}

}