android 实现保存文件至SD卡实例

来源：互联网发布：知乎爬虫加载编辑：程序博客网时间：2024/06/02 06:18

前言

我们实现一个功能，输入要保存的内容、文件名，点击保存按钮即可保存至SD卡。

1.布局文件activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content" >        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="内容" />        <EditText            android:id="@+id/contentEditText"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:lines="4" />    </LinearLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content" >        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="文件名" />        <EditText            android:id="@+id/fileNameEditText"            android:layout_width="141dp"            android:layout_height="wrap_content"            android:ems="10" >            <requestFocus />        </EditText>    </LinearLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:gravity="center_horizontal" >        <Button            android:id="@+id/saveBtn"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="保存至SD卡" />    </LinearLayout></LinearLayout>

2.MainActivity

package cn.sehzh.sdcardtester;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import android.app.Activity;import android.os.Bundle;import android.os.Environment;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends Activity {private EditText mContentEditText, mFileNameEditText;private Button mSaveBtn;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);init();}private void init() {findView();mSaveBtn.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {String content, fileName;content = mContentEditText.getText().toString();fileName = mFileNameEditText.getText().toString();saveToSDcard(content, fileName);}});}protected void saveToSDcard(String content, String fileName) {if (isExternalStorageWritable()) {File newFile;FileOutputStream fileOutputStream;newFile = new File(Environment.getExternalStorageDirectory() + File.separator + fileName + ".txt");try {newFile.createNewFile();fileOutputStream = new FileOutputStream(newFile);fileOutputStream.write(content.getBytes());fileOutputStream.close();Toast.makeText(this, "文件保存成功！", Toast.LENGTH_SHORT).show();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}} else {Toast.makeText(this, "未发现SD卡！", Toast.LENGTH_SHORT).show();}}private void findView() {mContentEditText = (EditText) findViewById(R.id.contentEditText);mFileNameEditText = (EditText) findViewById(R.id.fileNameEditText);mSaveBtn = (Button) findViewById(R.id.saveBtn);}/* Checks if external storage is available for read and write */public boolean isExternalStorageWritable() {String state = Environment.getExternalStorageState();if (Environment.MEDIA_MOUNTED.equals(state)) {return true;}return false;}}

3.实现效果

保存的文件如下：

注意添加权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

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