Question

我正在尝试访问Android设备上的文本文件。我已成功写入并在我的代码中读取文件，但我希望能够访问该文件，以便我可以将其复制并移动到其他位置。

我的代码包含在下面，运行时没有错误。但是，我只是编写了大量编辑的基本代码，试图解决这个问题。

虽然未显示，但默认方法onCreate在方法中包含的默认代码之后按顺序运行createFile（），writeFile（“Hello File！”）和readFile（）。

Context context = this;

String autoFileName = "AutoDataFile.txt";
File path;
File myFile;

String insideText = "NOTHING";

public void createFile(){
    path = context.getFilesDir();
    myFile = new File(path, autoFileName);
}

public void writeFile(String text){
    try {
        FileOutputStream stream = new FileOutputStream(myFile);
        stream.write(text.getBytes());
        stream.write(",".getBytes());
        stream.write("Second input!".getBytes());
        stream.close();
        System.out.println("SUCCESS?: MAY HAVE WRITTEN TO FILE");
    } catch (Exception e){
        e.printStackTrace();
        System.out.println("ERROR: DID NOT WRITE TO FILE");
    }
}

public void readFile(){
    try {
        Scanner fileStream = new Scanner(myFile);
        insideText += " " + fileStream.useDelimiter(",").nextLine();
        System.out.println("SUCCESS?: MAY HAVE READ FROM FILE");
    } catch (FileNotFoundException e) {
        e.printStackTrace();
        System.out.println("ERROR: DID NOT READ FROM FILE");
    }
}

Answer 1

你可以这样做：

到你的build.gradle

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

然后添加到您的清单

public void writeCSV(ArrayList<String> content) {
    //Point a directory to the external storage
    File exportDir = new File(Environment.getExternalStorageDirectory(), "");
    if (!exportDir.exists()) {
        exportDir.mkdirs();
    }
    //formatter for the date associated with the file name
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
    //inner file to be the location of the csv 
    File csv = new File(exportDir, "csvdata_" + sdf.format(Calendar.getInstance().getTime()) + ".csv");
    try {
        //create the file and the writer which will append our data
        csv.createNewFile();
        CSVWriter writer = new CSVWriter(new FileWriter(csv));
         //loop through some desired content
        for (String s : content) {
           //writes the string and separates by a comma (spreadsheet format)
           writer.writeNext(s);
        }
        //close the writer
        writer.close();
    } catch(Exception e) {
        e.printStackTrace();
    }
} //end

然后将您的文件设为：

stylesheets/bootstrap.css

如何在Android上创建，编写和读取文件，然后在设备上访问它？

1 个答案: