读写SD
2024-10-14 23:28:49
public class SD_Files_RW extends Activity implements OnClickListener{ private String Text_of_input; private Button button_01,button_02;
private EditText ed_text;
private TextView text_view; private File sdCardDir;
private File saveFile;
private FileOutputStream outStream;
private FileInputStream inStream; /** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main); sdCardDir = Environment.getExternalStorageDirectory();
saveFile = new File(sdCardDir,"wms.txt"); ed_text = (EditText) findViewById(R.id.edit_01);
text_view = (TextView) findViewById(R.id.text_01); button_01 = (Button)findViewById(R.id.button_01);
button_01.setOnClickListener(this); button_02 = (Button)findViewById(R.id.button_02);
button_02.setOnClickListener(this);
} // Button 监听
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch(v.getId())
{
case R.id.button_01:
{
Toast.makeText(SD_Files_RW.this, "开始写入文件!", Toast.LENGTH_SHORT).show();
Write_Files();
//text_view.setText(ed_text.getText().toString());
}break;
case R.id.button_02:
{
Toast.makeText(SD_Files_RW.this, "开始读出文件!", Toast.LENGTH_SHORT).show();
Read_Files(); }break;
} } private void Write_Files()
{ //得到用户输入字符
Text_of_input = ed_text.getText().toString(); if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){ //创建 初始化 流对象
try{ outStream = new FileOutputStream(saveFile);
}
catch (FileNotFoundException e){
Toast.makeText(this, "文件不存在!", Toast.LENGTH_SHORT).show();
return ;
} try { //把内容写入文件
outStream.write(Text_of_input.getBytes()); } catch (FileNotFoundException e) { // TODO Auto-generated catch block
Toast.makeText(this, "文件未发现异常!", Toast.LENGTH_SHORT).show(); } catch (IOException e) { // TODO Auto-generated catch block
Toast.makeText(this, "文件读写异常!", Toast.LENGTH_SHORT).show(); }
catch (NullPointerException e){
Toast.makeText(this, "文件读写空指针异常!", Toast.LENGTH_SHORT).show();
}
finally { try { //关闭文件输出流 outStream.close(); } catch (IOException e) { // TODO Auto-generated catch block
Toast.makeText(this, "文件读写异常!", Toast.LENGTH_SHORT).show(); } Toast.makeText(this, "文件写入成功!", Toast.LENGTH_SHORT).show(); } }else {
Toast.makeText(this, "内存卡不存在!", Toast.LENGTH_SHORT).show();
return ;
} } private void Read_Files()
{ int len; //然后创建一个字节数组输出流
byte[] buffer = new byte[1024]; ByteArrayOutputStream ostream = new ByteArrayOutputStream(); if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){ //创建 初始化 流对象
try{ inStream = new FileInputStream(saveFile);
Log.v("Instance inStream", "实例化inStream!");
}
catch (FileNotFoundException e){
Toast.makeText(this, "文件不存在!", Toast.LENGTH_SHORT).show();
return ;
} try{ Log.v("Read", "读数据!"); while((len=inStream.read(buffer))!=-1){
ostream.write(buffer, 0, len); } Log.v("Read", "读成功!"); }catch (IOException e){
Toast.makeText(this, "读 异常!", Toast.LENGTH_SHORT).show();
} try{
//最后关闭输入流和输出流
inStream.close();
ostream.close(); Log.v("Read", "读成功!"); }catch (IOException e){
Toast.makeText(this, "读 异常!", Toast.LENGTH_SHORT).show();
} String str = new String(ostream.toByteArray()); Log.v("Disp", "文本显示!"); text_view.setText(str); }else{
Toast.makeText(this, "内存卡不存在!", Toast.LENGTH_SHORT).show();
return ;
}
} }
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