java 从文本字段输入中过滤 JList

Filtering a JList from text field input

提问by Mohamed Bawaneen

i have a text field stick to jList1 and i need to filter j list entities depend on values entered by user in the text box like below if j list values {"one","two","three"......etc }if user entered "three" in the text box to pop up the list and select the row with three value to selected relating index.

我有一个文本字段坚持 jList1，我需要过滤 j 列表实体取决于用户在文本框中输入的值，如下所示如果 j 列表值{"one","two","three"......etc }如果用户在文本框中输入“三”以弹出列表并选择具有三个值的行到选定的相关索引。

private void jTbandnoActionPerformed(java.awt.event.ActionEvent evt)   
{                                         
     // TODO add your handling code here:
     String tXT=jTbandno.getText();
    jList2.collections.equal(tXt);
    int index = jList2.getSelectedIndex();
    JOptionPane.showMessageDialog(null, index);
 }            

回答by Paul Samsotha

Well you can create method to filter out the values by using

那么你可以创建方法来使用

• DefaultListModel#removeElement, and
• DefaultListModel#addElement

• DefaultListModel#removeElement， 和
• DefaultListModel#addElement

Generally when dealing with data or components that use models, we should interact with the model and not the component. So you can have a method something like

通常在处理使用模型的数据或组件时，我们应该与模型而不是组件进行交互。所以你可以有一个类似的方法

private String[] defaultValues =  {
    "a", "ab", "abc", "abcd", "abcde", "abcdef", "absdefg", "abcdefgh",
    "abcdefghi", "abcdefghij", "abcdefghijk", "abcdefghijkl", "abcdefghijklm",
};

public void filterModel(DefaultListModel<String> model, String filter) {
    for (String s : defaultValues) {
        if (!s.startsWith(filter)) {
            if (model.contains(s)) {
                model.removeElement(s);
            }
        } else {
            if (!model.contains(s)) {
                model.addElement(s);
            }
        }
    }
}

When you need to filter, for example in the DocumentListenerof a text field, just get the text of the text field, and call this method, passing in the model and the filter string. Something like

当你需要过滤的时候，比如在DocumentListener一个文本字段的时候，只需要获取这个文本字段的文本，然后调用这个方法，传入模型和过滤字符串。就像是

private void filter() {
    String filter = field.getText();
    filterModel((DefaultListModel<String>)jList.getModel(), filter);
}

Here's a complete example. You may want to implement some more complicated filtering such as including sorting into search filter. This is just a simple case example.

这是一个完整的例子。您可能想要实现一些更复杂的过滤，例如将排序包括到搜索过滤器中。这只是一个简单的案例。

import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.ListModel;
import javax.swing.SwingUtilities;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;

public class DynamicListDemo {

    private String[] defaultValues =  {
        "a", "ab", "abc", "abcd", "abcde", "abcdef", "absdefg", "abcdefgh",
        "abcdefghi", "abcdefghij", "abcdefghijk", "abcdefghijkl", "abcdefghijklm",
    };
    private JList jList = createJList();

    public DynamicListDemo() {
        JFrame frame = new JFrame();
        frame.add(new JScrollPane(jList));
        frame.add(createTextField(), BorderLayout.PAGE_END);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    private JTextField createTextField() {
        final JTextField field = new JTextField(15);
        field.getDocument().addDocumentListener(new DocumentListener(){
            @Override public void insertUpdate(DocumentEvent e) { filter(); }
            @Override public void removeUpdate(DocumentEvent e) { filter(); }
            @Override public void changedUpdate(DocumentEvent e) {}
            private void filter() {
                String filter = field.getText();
                filterModel((DefaultListModel<String>)jList.getModel(), filter);
            }
        });
        return field;
    }

    private JList createJList() {
        JList list = new JList(createDefaultListModel());
        list.setVisibleRowCount(6);
        return list;
    }

    private ListModel<String> createDefaultListModel() {
        DefaultListModel<String> model = new DefaultListModel<>();
        for (String s : defaultValues) {
            model.addElement(s);
        }
        return model;
    }

    public void filterModel(DefaultListModel<String> model, String filter) {
        for (String s : defaultValues) {
            if (!s.startsWith(filter)) {
                if (model.contains(s)) {
                    model.removeElement(s);
                }
            } else {
                if (!model.contains(s)) {
                    model.addElement(s);
                }
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                new DynamicListDemo();
            }
        });
    }
}

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UPDATE:As mKorbel pointed out the obvious, this may be a better use case for a JTablewith a single column, where sorting and filtering is already part of the API.

更新：正如 mKorbel 所指出的那样，这可能是一个更好的用例，用于JTable单列，其中排序和过滤已经是 API 的一部分。

See How to Use Tables: Sorting and Filtering

请参阅如何使用表格：排序和过滤