android openFileInput openFileOutput

android openFileInput openFileOutput


openFileInput 開啟應用程式的資料檔案夾下的name檔案對應的輸入資料流

openFileOutput開啟應用程式的資料檔案夾下的name檔案對應的輸出資料流

 

下面是讀寫的例子

public class MainActivity extends Activity {

private EditText et1;
private EditText et2;
private Button bt1;
private Button bt2;
final String FILE_NAME = "crazyit.bin";

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et1 = (EditText) findViewById(R.id.editText1);
et2 = (EditText) findViewById(R.id.editText2);
bt1 = (Button) findViewById(R.id.button1);
bt2 = (Button) findViewById(R.id.button2);
bt1.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
write(et1.getText().toString());
et1.setText("");
}
});
bt2.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
et2.setText(read());
}
});

}

private String read(){

try {
FileInputStream fis = openFileInput(FILE_NAME);
byte[] buff = new byte[1024];
int hasread = 0;
StringBuilder sb = new StringBuilder();
while((hasread=fis.read(buff))>0){
sb.append(new String(buff,0,hasread));
}
fis.close();
return sb.toString();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null ;
}

private void write(String content){

try {
FileOutputStream fos = openFileOutput(FILE_NAME, MODE_APPEND);
PrintStream ps = new PrintStream(fos);
ps.println(content);
ps.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}


}