Android--手机外部SD卡存储

来源：互联网发布：码云的独立域名编辑：程序博客网时间：2024/06/09 21:20

首先需要一个如图所示的布局

这样的布局好些，就不多说了

主要涉及的知识点

数据保存的路径：

路径1：/storage/sdcard/Android/data/packageName/Files
路径2：/storage/sdcard/xxx/
路径1：其它应用可以访问，应用程序卸载时删除
路径2：其它应用可以访问，应用程序卸载时不会删除
必须保证sd卡必须挂载

一.路径1的保存和读取

先保存

public void sure1(View v) throws Exception {        //判断sd卡状态，如果是挂载状态才保存，否则将进行提示        if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {            //读取文件的内容以及文件名            String name = et_name.getText().toString();            String content = et_content.getText().toString();            //得到制定的outputStream                //得到sd下的files路径                String filesPath = getExternalFilesDir(null).getAbsolutePath();                //组成完整的路径                String path = filesPath+"/"+name;            //创建FileOutputSream            FileOutputStream fos = new FileOutputStream(path);            //写数据            fos.write(content.getBytes("utf-8"));            fos.close();            //提示            Toast.makeText(this,"保存成功",Toast.LENGTH_SHORT).show();        } else {            Toast.makeText(this,"请插入SD卡",Toast.LENGTH_SHORT).show();        }    }

读取

 public void read1(View v) throws Exception {        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {            //得到路径            String name = et_name.getText().toString();            String filePath = getExternalFilesDir(null).getAbsolutePath();            String path = filePath+"/"+name;            //创建FileInputStream            FileInputStream fis = new FileInputStream(path);            ByteArrayOutputStream baos = new ByteArrayOutputStream();            byte [] buffer = new byte[1024];            int len=-1;            while ((len=fis.read(buffer))!=-1) {                baos.write(buffer,0,len);            }            String content = baos.toString();            et_content.setText(content);        } else {            Toast.makeText(this,"请插入SD卡",Toast.LENGTH_SHORT).show();        }    }

二路径2的保存和读取

保存

public void sure2(View v) throws Exception {        //判断sd卡是否挂载        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {            //读取输入的文件名以及文件内容            String content= et_content.getText().toString();            String name = et_name.getText().toString();            //得到指定文件的OutputStream           // 1)/storage/sdcard            String sdPath = Environment.getExternalStorageDirectory().getAbsolutePath();            // 2)/storage/sdcard/fanny/(没有的话就创建)            File file = new File(sdPath+"/fanny");            if (!file.exists()) {                file.mkdirs();//创建文件夹            }            //3)/storage/sdcard/fanny/Xxx.txt            String path = sdPath+"/fanny"+name;            //创建输出流            FileOutputStream fos = new FileOutputStream(path);            //写数据            fos.write(content.getBytes("utf-8"));            fos.close();            Toast.makeText(this,"保存成功",Toast.LENGTH_SHORT).show();        } else {            Toast.makeText(this,"请插入sd卡",Toast.LENGTH_SHORT).show();        }    }

读取

public void read2(View V) throws Exception {        //判断sd卡是否挂载        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {            //得到输入的文件名            String name = et_name.getText().toString();            String filePath = Environment.getExternalStorageDirectory().getAbsolutePath();            String path = filePath+"/fanny"+name;            //得到指定文件的FileInputStream            FileInputStream fis = new FileInputStream(path);            ByteArrayOutputStream baos = new ByteArrayOutputStream();            byte [] buffer = new byte[2014];            int len = -1;            while ((len=fis.read(buffer))!=-1) {                baos.write(buffer,0,len);            }           String content = baos.toString();            et_content.setText(content);        } else {            Toast.makeText(this,"请插入SD卡",Toast.LENGTH_LONG).show();        }    }

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