使用文本框更改Java中的字体大小

Question

好吧，所以我需要一些帮助手，我使用一组varibles来声明我的字体等，我已经通过使用deriveFont使粗体和斜体函数工作方法 - 创建一个新的字体和应用新的风格等

这一个更棘手，因为即时通讯从文本框中获取值并将其应用到fontSize变量，然后将其应用到我有那里的currentFont。 ..

HELP ?! :(

我的代码片段低于...

public class Practice01 extends javax.swing.JFrame { 

private int fontStyle; 
private int fontSize = 12; 


private void changeSize(){ 

    Font currentFont = edtText.getFont(); //getting the current font 
    fontSize = Integer.parseInt(txtSize.getText()); //getting the number input from the text box and putting it to the fontSize variable 
    txtSize.setText(Integer.toString(fontSize)); //setting the txtSize entry to the fontSize variable? 
    currentFont.deriveFont(fontSize); //deriving a new font 
    edtText.setFont(currentFont.deriveFont(fontSize)); //setting the new font and size to the text box. 


} 

，这里是我的字体变位...

Font serifFont; 
Font monoFont; 
Font sansserifFont; 

public Practice01() { 
    serifFont = new Font ("Serif", fontStyle, fontSize); 
    monoFont = new Font ("Monospaced", fontStyle, fontSize); 
    sansserifFont = new Font ("SansSerif", fontStyle, fontSize); 
    initComponents(); 
} 

Answer 1

当心，Font#derive(int)改变字体样式，而不是它的大小，你可以尝试使用Font#deriveFont(float)这是用来更改字体的大小...

此外，deriveFont创建一个的新实例根据您提供的，所以你需要保持对它的引用，例如值...

Font font = currentFont.deriveFont((float)fontSize); //deriving a new font 
edtText.setFont(font); 

更新与例如

import java.awt.Dimension; 
import java.awt.EventQueue; 
import java.awt.Font; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.GridBagLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JTextField; 
import javax.swing.UIManager; 
import javax.swing.UnsupportedLookAndFeelException; 

public class FontTest { 

    public static void main(String[] args) { 
     new FontTest(); 
    } 

    public FontTest() { 
     EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
       } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { 
        ex.printStackTrace(); 
       } 

       JFrame frame = new JFrame("Testing"); 
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
       frame.add(new TestPane()); 
       frame.pack(); 
       frame.setLocationRelativeTo(null); 
       frame.setVisible(true); 
      } 
     }); 
    } 

    public class TestPane extends JPanel { 

     private JTextField field; 

     public TestPane() { 
      setLayout(new GridBagLayout()); 
      field = new JTextField(5); 
      add(field); 
      field.addActionListener(new ActionListener() { 
       @Override 
       public void actionPerformed(ActionEvent e) { 
        String text = field.getText(); 
        try { 
         float size = Float.parseFloat(text); 
         Font font = field.getFont(); 
         font = font.deriveFont(size); 
         field.setFont(font); 
         revalidate(); 
        } catch (Exception exp) { 
         exp.printStackTrace(); 
        } 
       } 
      }); 
     } 

    } 

}