Question

我真的可以在Java中使用三态复选框。这听起来很简单，但我只看到了ugly implementations [注意：链接现在已经破了]。

三个单选按钮只占用太多空间，在我的情况下可能会让用户感到困惑。它基本上用于搜索对话框。我需要真实，虚假或“不关心”的选择。人们使用不同的技术吗？

Answer 1

使用下拉列表。

Answer 2

我找到了一种方法，只需添加一个监听器即可创建一个三态复选框：


public class TriStateActionListener implements ActionListener{
    final protected Icon icon;

    public TriStateActionListener(Icon icon){
        this.icon=icon;
    }

    public static Boolean getState(javax.swing.JCheckBox cb){
        if (cb.getIcon()==null) return null;
        if (cb.isSelected()) return true;
        else return false;
    }

    public void actionPerformed(ActionEvent e) {
        javax.swing.JCheckBox cb=(javax.swing.JCheckBox)e.getSource();
        if (!cb.isSelected()){
            cb.setIcon(icon);
        }
        else if (cb.getIcon()!=null){
            cb.setIcon(null);
            cb.setSelected(false);
        }
    }
}

然后在应用程序代码中，它只是一行：


jCheckBox1.addActionListener(new TriStateActionListener(getResourceMap().getIcon("TriStateIcon")));

在所有反馈之后，我认为下拉可能是更好的选择。但是，我想在这里为其他人分享我的代码。

Answer 3

enter image description here

在此实现中，只能通过编程方式设置三个状态。为了外观和感觉，它使用的图像必须放在同一个java包中。

enter image description here

public class TristateCheckBox extends JCheckBox {

    private static final long serialVersionUID = 1L;
    private boolean halfState;
    private static Icon selected = new javax.swing.ImageIcon(TristateCheckBox.class.getResource("selected.png"));
    private static Icon unselected = new javax.swing.ImageIcon(TristateCheckBox.class.getResource("unselected.png"));
    private static Icon halfselected = new javax.swing.ImageIcon(TristateCheckBox.class.getResource("halfselected.png"));

    @Override
    public void paint(Graphics g) {
        if (isSelected()) {
            halfState = false;
        }
        setIcon(halfState ? halfselected : isSelected() ? selected : unselected);
        super.paint(g);
    }

    public boolean isHalfSelected() {
        return halfState;
    }

    public void setHalfSelected(boolean halfState) {
        this.halfState = halfState;
        if (halfState) {
            setSelected(false);
            repaint();
        }
    }
}

示例框架：

public class NewJFrame19 extends javax.swing.JFrame {

    private final TristateCheckBox myCheckBox;

    public NewJFrame19() {
        myCheckBox = new TristateCheckBox();
        myCheckBox.setText("123123");
        add(myCheckBox);

        jButton1 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        getContentPane().setLayout(new java.awt.FlowLayout());

        jButton1.setText("jButton1");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });
        getContentPane().add(jButton1);

        pack();
    }

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        myCheckBox.setHalfSelected(true);
    }                                        

    public static void main(String args[]) {

        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Windows".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame19.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame19.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame19.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame19.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame19().setVisible(true);
            }
        });
    }
    private javax.swing.JButton jButton1;
}

Answer 4

JIDE在Common Layer开放了一些非常好的功能，其中一个恰好是三态复选框

Tristate checkboxes

我建议您运行webstart demo以确定它是否符合您的需求

Answer 5

我不知道为什么有人会给这些解决方案添加额外的图标png文件，而 java api 为覆盖 paintIcon（..）方法提供了很好的功能。

记住CheckBox状态的最佳轻量级解决方案是IMO ClientProperty 属性。

enter image description here

/*
 * Tri-state checkbox example
 * @s1w_
*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;


class TCheckBox extends JCheckBox implements Icon, ActionListener {

    final static boolean MIDasSELECTED = true;  //consider mid-state as selected ?


    public TCheckBox() { this(""); }

    public TCheckBox(String text) {
        super(text);
        putClientProperty("SelectionState", 0);
        setIcon(this);
        addActionListener(this);
    }

    public TCheckBox(String text, int sel) {
        /* tri-state checkbox has 3 selection states:
         * 0 unselected
         * 1 mid-state selection
         * 2 fully selected
        */
        super(text, sel > 1 ? true : false);

        switch (sel) {
            case 2: setSelected(true);
            case 1:
            case 0:
                putClientProperty("SelectionState", sel);
                break;
           default:
                throw new IllegalArgumentException();
        }
        addActionListener(this);
        setIcon(this);
    }

    @Override
    public boolean isSelected() {
        if (MIDasSELECTED && (getSelectionState() > 0)) return true;
        else return super.isSelected();
    }

    public int getSelectionState() {
        return (getClientProperty("SelectionState") != null ? (int)getClientProperty("SelectionState") :
                                         super.isSelected() ? 2 :
                                         0);
    }

    public void setSelectionState(int sel) {
        switch (sel) {
            case 2: setSelected(true);
                    break;
            case 1: 
            case 0: setSelected(false);
                    break;
           default: throw new IllegalArgumentException();
        }
        putClientProperty("SelectionState", sel);
    }


    final static Icon icon = UIManager.getIcon("CheckBox.icon");

    @Override
    public void paintIcon(Component c, Graphics g, int x, int y) {
        icon.paintIcon(c, g, x, y);
        if (getSelectionState() != 1) return;

        int w = getIconWidth();
        int h = getIconHeight();
        g.setColor(c.isEnabled() ? new Color(51, 51, 51) : new Color(122, 138, 153));
        g.fillRect(x+4, y+4, w-8, h-8);

        if (!c.isEnabled()) return;
        g.setColor(new Color(81, 81, 81));
        g.drawRect(x+4, y+4, w-9, h-9);
    }

    @Override
    public int getIconWidth() {
        return icon.getIconWidth();
    }

    @Override
    public int getIconHeight() {
        return icon.getIconHeight();
    }

    public void actionPerformed(ActionEvent e) {
        TCheckBox tcb = (TCheckBox)e.getSource();
        if (tcb.getSelectionState() == 0)
            tcb.setSelected(false);

        tcb.putClientProperty("SelectionState", tcb.getSelectionState() == 2 ? 0 :
                                                     tcb.getSelectionState() + 1);

        // test
        System.out.println(">>>>IS SELECTED: "+tcb.isSelected());
        System.out.println(">>>>IN MID STATE: "+(tcb.getSelectionState()==1));
    }
}

用法：TCheckBox tcb = new TCheckBox("My CheckBox");

Answer 6

“丑陋的实施”是一个旧的链接。该页面上的一条建议在几年前就已更新。我没有测试过旧的实现，所以我不知道新的实现是好还是坏。

TristateCheckBox Revisited

Answer 7

三态复选框是Treeview的标准UI惯用语，带有部分检查的子节点。它们广泛用于复杂分层视图（如Google Earth）中的图层管理。

Answer 8

我只使用您发布的那个。

只要你的复杂性在另一个类（有效）并且它的行为就像任何其他控件一样，谁在乎呢？（这似乎是所有挥杆背后的假设，大多数挥杆类似乎都是关于这种复杂的。）

Answer 9

更改用户界面。三态复选框很不寻常，可能会让用户感到困惑。下拉是一个不错的选择，但是在对话框中多出一次，也会给用户带来很多困惑。

Java中的三态复选框

9 个答案: