Question

我正在创建一个写入.txt文件的应用程序，并在每个“保存”结束时，我想要输入日期和时间。

这是我的代码，它将时间/日期转换为字符串，然后将其保存到文件中。

public class SaveFile extends Activity {

EditText txtData;
EditText txtData2;
Button btnWriteSDFile;
Button btnDelete;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.form);

SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss");
    Date date = new Date(System.currentTimeMillis());
    final String datetime = dateFormat.format(date);

txtData = (EditText) findViewById(R.id.input1);
txtData2 = (EditText) findViewById(R.id.input2);

btnWriteSDFile = (Button) findViewById(R.id.save);
btnWriteSDFile.setOnClickListener(new OnClickListener() {

public void onClick(View v) {
    // write on SD card file data in the text box

    try {
        BufferedWriter out = new BufferedWriter(new FileWriter("/sdcard/data_file.txt", true));
        out.write(txtData.getText() + "," + txtData2.getText() + "," + datetime.toString());
        out.write("\r\n");
        out.close();
        Toast.makeText(v.getContext(),"Saved",Toast.LENGTH_SHORT).show();
    } catch (Exception e) {
        Toast.makeText(v.getContext(), e.getMessage(),Toast.LENGTH_SHORT).show();
    }


        txtData.setText("");
        txtData2.setText("");


}// onClick
}); // btnWriteSDFile

}// onCreate

}// AndSDcard

我遇到的问题是每次我节省时间都不会更新。每一行有相同的时间和日期？任何人都可以帮忙吗？问候

Answer 1

您获得当前时间并重复使用它。您应该在事件处理程序中获取当前时间：

public void onClick(View v) {
    // write on SD card file data in the text box    
    try {
        BufferedWriter out = new BufferedWriter(new FileWriter("/sdcard/data_file.txt", true));
        Date date = new Date(System.currentTimeMillis());
        final String datetime = dateFormat.format(date);       
        out.write(txtData.getText() + "," +
                  txtData2.getText() + "," +
                  datetime.toString());
        out.write("\r\n");
        out.close();
        Toast.makeText(v.getContext(),"Saved",Toast.LENGTH_SHORT).show();
    } catch (Exception e) {
        Toast.makeText(v.getContext(), e.getMessage(),Toast.LENGTH_SHORT).show();
    }

    txtData.setText("");
    txtData2.setText("");
}

Answer 2

您总是在onCreate()上仅创建一次的datetime对象上写入时间。您应该每次都在onClick()获取当前时间。

为此，您应该将格式化程序作为类对象，然后在每次写入文件时创建新日期：

out.write(txtData.getText() + "," + txtData2.getText() +
          "," + dateFormat.format(new Date());

请注意new Date()会自动获取当前时间和日期。

Android - 时间不更新

2 个答案: