Question

如果我有一个很长的NSTextStorage并且我知道NSTextContainer的CGSize，我如何计算文本页数？是否有针对此事的标准程序或某种动态计数的方法？我找不到一个很好的教程，可以使用自定义字体从原始文本制作iBooks书（我需要绘制20-50页的文本）。

Answer 1

我找到了一种使用TextKit的NSLayoutManager计算多个页面的好方法。我创建NSTextContainers时只计算页数

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Calculator extends JFrame {
    private JTextField Number1TxtField;
    private JTextField Number2TxtField;
    private JTextField ResultTxtField;
    private JButton add;
    private JButton subtract;
    private JButton multiply;
    private JButton divide;

    public Calculator() { // class for the calculator

        JPanel topPanel = new JPanel();

        topPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 8, 5));
        topPanel.add(new JLabel("Number 1"));
        Number1TxtField = new JTextField(5);
        topPanel.add(Number1TxtField);
        topPanel.add(new JLabel("Number 2"));
        Number2TxtField = new JTextField(5);
        topPanel.add(Number2TxtField);
        topPanel.add(new JLabel("Result"));
        ResultTxtField = new JTextField(8);
        topPanel.add(ResultTxtField);
        ResultTxtField.setEditable(false);
        topPanel.add(ResultTxtField);

        // new JPanel
        JPanel buttonsPanel = new JPanel();
        buttonsPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 8, 5));
        add = new JButton("Add");
        buttonsPanel.add(add);

        subtract = new JButton("Subtract");
        buttonsPanel.add(subtract);

        multiply = new JButton("Multiply");
        buttonsPanel.add(multiply);

        divide = new JButton("Divide");
        buttonsPanel.add(divide);

        ButtonListener btnlistener = new ButtonListener();

        add.addActionListener(btnlistener);

        subtract.addActionListener(btnlistener);

        multiply.addActionListener(btnlistener);

        divide.addActionListener(btnlistener);

        getContentPane().add(topPanel, BorderLayout.NORTH);
        getContentPane().add(buttonsPanel);
    }

    class ButtonListener implements ActionListener {

        @Override

        public void actionPerformed(ActionEvent e) {

            String num1str = Number1TxtField.getText();

            double num1 = Double.parseDouble(num1str);

            String num2str = Number2TxtField.getText();

            double num2 = Double.parseDouble(num2str);

            double result;

            if (e.getSource() == add)
                result = num1 + num2;

            else if (e.getSource() == subtract)
                result = num1 - num2;

            else if (e.getSource() == multiply)
                result = num1 * num2;

            else // DivideButton
                result = num1 / num2;

            ResultTxtField.setText(String.valueOf(result));

        }
    }

    public static void main(String[] args) {

        Calculator frame = new Calculator();

        frame.setTitle("Calculator");

        frame.pack();

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.setVisible(true);
    }
}

columnCount是您使用多列布局

时的列数

frameForViewAtIndex为scrollView

中的当前textView返回CGRect

UIPageViewController / TextKit计算页数

1 个答案: