Question

我正在尝试使用try和catch创建文本格式的逗号分隔文件。为此，我正在使用库PrintWriter。但是，我还不能互相打印所有行。我创建了一个列表来存储每次迭代中创建的每一行，然后尝试在列表上使用for来将每个元素打印为文件中的一行：

private void initializeDraggablePanel(Fragment fragmentView, Fragment bottomFragment) {
        draggablePanel.removeAllViews();
        draggablePanel.setFragmentManager(getSupportFragmentManager());
        draggablePanel.setTopFragment((Fragment) fragmentView);
        draggablePanel.setBottomFragment(bottomFragment);
        draggablePanel.setVisibility(View.VISIBLE);
        draggablePanel.setClickToMaximizeEnabled(true);
        draggablePanel.setDraggableListener(new DraggableListener() {
            @Override
            public void onClosedToLeft() {
                draggablePanel.removeAllViews();
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
            }

            @Override
            public void onMinimized() {
                isFullScFromMini = true;
                pipHandler.removeCallbacks(runnapipa);
                pipHandler.postDelayed(runnapipa, PIP_DELAY);
                draggablePanel.disableBottomView(true);
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
            }

            @Override
            public void onClosedToRight() {
                draggablePanel.removeAllViews();
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
            }

            @Override
            public void onUnMaximized() {
                draggablePanel.disableBottomView(false);
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
            }

            @Override
            public void onMaximized() {
                isFullScFromMini = true;
                pipHandler.removeCallbacks(runnapipa);
                pipHandler.postDelayed(runnapipa, PIP_DELAY);
                draggablePanel.disableBottomView(false);
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_USER);
            }
        });
        TypedValue typedValue = new TypedValue();
        getResources().getValue(R.dimen.x_scale_factor, typedValue, true);
        float xScaleFactor = typedValue.getFloat();
        typedValue = new TypedValue();
        getResources().getValue(R.dimen.y_scale_factor, typedValue, true);
        float yScaleFactor = typedValue.getFloat();
        draggablePanel.setXScaleFactor(xScaleFactor);
        draggablePanel.setYScaleFactor(yScaleFactor);
        draggablePanel.setTopViewHeight(
                getResources().getDimensionPixelSize(R.dimen.top_fragment_height));
        draggablePanel.setTopFragmentMarginRight(
                getResources().getDimensionPixelSize(R.dimen.top_frag_right_margin));
        draggablePanel.setTopFragmentMarginBottom(
                getResources().getDimensionPixelSize(R.dimen.top_fragment_margin));
        draggablePanel.initializeView();
        draggablePanel.maximize();
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_USER);
    }

但是，我在文件中得到的结果是

for(int i=0;i<listA.size();i++) {
    writer.println(listA.get(i));
}

我期望：

Name_DS_1,LineString_1,UFI_1,Name_DS_2,LineString_2,UFI_2
Name1,Line1,Ufi1,Name2,Line2,Ufi2

我的整个代码是：

Name_DS_1,LineString_1,UFI_1,Name_DS_2,LineString_2,UFI_2
Name1,Line1,Ufi1,Name2,Line2,Ufi2
Name1,Line1,Ufi1,Name2,Line2,Ufi2
Name1,Line1,Ufi1,Name2,Line2,Ufi2

Answer 1

这可能是解决您问题的方法，在这里您可以找到解决方法

 JFrame frame = new JFrame();
                ImageIcon icon = new ImageIcon(imgPath);
                JLabel label = new JLabel(icon);
                frame.add(label);
                frame.setTitle(imgPath.substring(imgPath.lastIndexOf("\\")+1));
                frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
                frame.pack();
                frame.setVisible(true);
                frame.setResizable(false); 

                //function to select area by mouse click
                addHandlerToDraw(label,frame,icon);

一些提示：

您无需关闭private void addHandlerToDraw(JLabel label, JFrame frame, ImageIcon img) { label.addMouseListener(new MouseAdapter() { Point start = new Point(); Rectangle captureRect; int k=0; @Override public void mouseClicked(java.awt.event.MouseEvent e) { if(k==0) { start = e.getPoint(); k=1; } else { k = 0; Point end = e.getPoint(); captureRect = new Rectangle(start, new Dimension(end.x-start.x, end.y-start.y)); } repaint(captureRect, frame, img, label); label.repaint(); } });中声明的private void repaint(Rectangle rect, JFrame frame, ImageIcon img, JLabel label) { BufferedImage bi = new BufferedImage( img.getIconWidth(), img.getIconHeight(), BufferedImage.TYPE_INT_RGB); Graphics2D g1 = bi.createGraphics(); g1.setColor(new Color(200,30,30,45)); if(rect != null) { g1.drawRect(rect.x, rect.y, rect.width, rect.height); frame.remove(label); frame.add(new JLabel(new ImageIcon(bi))); frame.setVisible(true); }}
由于您已经在使用public class App { public static List<String> listA = new ArrayList<>(); public static void main(String[] args) { matchSplits(); } public static void matchSplits() { String header = "Name_DS_1" + "," + "LineString_1" + "," + "UFI_1" + "," + "Name_DS_2" + "," + "LineString_2" + "," + "UFI_2"; String fileName = "foo.csv"; // your file name here File file = new File(fileName); try (PrintWriter writer = new PrintWriter(file)) { // no need to check if k == 0, this is outside the loop listA.add(header); // prepare your data here for (int k = 0; k < 3; k++) { String Name_DS_1 = "Name1"; String LineString_1 = "Line1"; String UFI_1 = "Ufi1"; String Name_DS_2 = "Name2"; String LineString_2 = "Line2"; String UFI_2 = "Ufi2"; String line = Name_DS_1 + "," + LineString_1 + "," + UFI_1 + "," + Name_DS_2 + "," + LineString_2 + "," + UFI_2; listA.add(line); } // write your lines here for (String s: listA) { writer.println(s); } } catch (FileNotFoundException e) { System.out.println(e.getMessage()); } } }，所以不需要PrintWriter
不需要两个计数器，try(...)就足够了（至少在此代码段中如此）

Answer 2

之所以会这样，是因为您在for循环范围内编写了writer.close（）。为（int k = 0; k <3; k ++）

尝试删除writer.close（）语句。由于该语句仅在k = 0时才关闭写入过程。

因为PrintWriter实例是在try-with-resource语句中声明的，所以无论try语句是正常完成还是突然完成（如果这些资源实现AutoCloseable接口），它将关闭。

尝试执行此操作，希望它将解决您的问题：）

使用printwriter创建一个文本文件，其中包含列表中的几行

2 个答案: