Question

我正在尝试从文本文件中读取，在满足新行字符时拆分内容并在TextView中显示结果。

这是我的readfromfile方法：

public String readFromFile(Context context) {
        String ret = "";
        try {
            InputStream inputStream = context.openFileInput("history.txt");
            if ( inputStream != null ) {
                InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
                BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
                String receiveString = "";
                StringBuilder stringBuilder = new StringBuilder();
                while ( (receiveString = bufferedReader.readLine()) != null ) {
                    //receiveString.split("\n");
                    //String[] split = receiveString.split("\n\\s*");
                    stringBuilder.append(receiveString);
                   // if((receiveString = bufferedReader.readLine()) == "\n"){
                   // }
                }
                inputStream.close();
                //stringBuilder.
                ret = stringBuilder.toString();
            }
        }
        catch (FileNotFoundException e) {
            Log.e("login activity", "File not found: " + e.toString());
            Toast.makeText(this, "You have not sent any messages!!", Toast.LENGTH_LONG).show();
        } catch (IOException e) {
            Log.e("login activity", "Can not read file: " + e.toString());
            Toast.makeText(this, "Cannot read from file!!", Toast.LENGTH_LONG).show();
        }
        return ret;
    }

这就是调用方法的地方：

String message = readFromFile(getApplicationContext()); // is this really needed? yes it is, use with readFromFile()
        TextView textView = new TextView(this);
        params2.addRule(RelativeLayout.BELOW, history.getId()); // this is very important for spacing using ids
        textView.setTextSize(14); //this might give an error or look weird on devices, horizontally and vertically
        textView.setText(message); // simplest fix is to force device to stick with horizontal, no common device is bigger than 5.5"
        //textView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
        textView.setId(View.generateViewId()); // This requires a minimum API 17
        textView.setGravity(Gravity.LEFT | Gravity.BOTTOM);
        layout.addView(textView, params2);

我认为问题可能是我使用的append字符串要显示，即我返回带有附加文本的字符串。

这是视图输出：

Output

我正在尝试从名为 history.txt 的文件加载，该文件包含使用字符串格式的应用程序发送的所有SMS。

这是writeToFile方法：

public void writeToFile(String data,Context context) {
        try {
            OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput("history.txt", Context.MODE_APPEND));
            //format data string here to include time stamp
            BufferedWriter writer = new BufferedWriter(outputStreamWriter);

            String currentDateTime = DateFormat.getDateTimeInstance().format(new Date());

                outputStreamWriter.append("\n");
                outputStreamWriter.append(data);
                outputStreamWriter.append(" ");
                outputStreamWriter.append(currentDateTime);
                writer.newLine();

                outputStreamWriter.close();

        }
        catch (IOException e) {
            Log.e("Exception", "File write failed: " + e.toString());
        }
    }

有什么想法吗？

Answer 1

检查Javadoc。 readLine()删除行终止符。如果您在输出时需要行，则必须自己添加行终止符：在这种情况下，您可以在阅读时添加\n或\r\n，因为您正在显示GUI中的数据。

Answer 2

也许您应该使用ListView。 ListView的每一行可以是文件中单行的单个TextView，也可以是多个TextView，如果您想将数据分解为格式良好的列。

Answer 3

这已通过添加和条件解决。由于变量的数量已设置且不会更改，因此在每8条读取行中，将跳过两行，如下所示：

 while ( (receiveString = bufferedReader.readLine()) != null ) {
                    //receiveString.split("\n");
                    //String[] split = receiveString.split("\n\\s*");
                    stringBuilder.append(receiveString);
                    if(i == 8) {
                        stringBuilder.append("\n");
                        i = 0;
                    }
                    stringBuilder.append("\n");
                   // if((receiveString = bufferedReader.readLine()) == "\n"){
                   i++;
                   // }
                }

谢谢你们的投入！

p.s正如@ Code-Apprentice指出的那样，ListView应该是从一开始就采用的方式。

使用BufferedReader Android时在新行上拆分

3 个答案: