如何使用 Java Netbeans 在 GUI 中执行选定的 ComboBox

Question

我想使用 Java Netbeans 在调色板 GUI 中执行一个 selected 项目。最近，我只能执行 'run' 按钮，没有任何 select 项目。我打算先 select 其中一个项目，然后执行按钮。这是代码：

User user = status.getUser();
        Date dated = status.getCreatedAt();
        PreparedStatement stmt = null;
        Connection conne = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            System.out.println("Connecting to database...");
            conne = DriverManager.getConnection("jdbc:mysql://localhost/jat?useUnicode=true&characterEncoding=UTF-8", "root", "");
            System.out.println(status);
            System.out.println("Inserting records into the table...");
            stmt = conne.prepareStatement("set names 'utf8'");
            stmt.execute();
            stmt = conne.prepareStatement("set character set utf8");
            stmt.execute();
            stmt = conne.prepareStatement("INSERT INTO tweet(ID,date,name,statusLocation,text,source) VALUES (?,?,?,?,?,?)");
            stmt.setInt(1, (int) status.getId());
            stmt.setString(2, getTimeStamp());
            stmt.setString(3, status.getUser().getScreenName());
            stmt.setString(4, user.getLocation());
            stmt.setString(5, status.getText());
            stmt.setString(6, status.getSource());
            stmt.executeUpdate();
            System.out.println("this record inserted!");
            System.out.println("==================");
        } catch (SQLException se) {
            se.printStackTrace();
        } catch (final Exception e) {
            e.printStackTrace();
        }
    }
    @Override
    public void onTrackLimitationNotice(int arg0) {
    }
    @Override
    public void onStallWarning(StallWarning sw) {
        throw new UnsupportedOperationException("Not supported yet."); 
    }
};       
FilterQuery fq = new FilterQuery();
double lat1 = 121.300000d;
double long1 = 25.020000d;
double lat2 = 121.380000d;
double long2 = 25.030000d;
twitterStream.addListener(listener);
double[][] bb = {{lat1, long1}, {lat2, long2}};
fq.locations(bb);
twitterStream.filter(fq);}

这是界面：

感谢任何评论！

Answer 1

Select 组合框。
右键单击弹出菜单。
在菜单中选择事件 -> 项目 -> 项目状态已更改。
它将设置一个函数，以便在选择项目时调用。

编辑成这样

private void jComboBox1ItemStateChanged(java.awt.event.ItemEvent evt) {                                            
    if(evt.getStateChange() == ItemEvent.SELECTED) {
        String selected_item = jComboBox1.getSelectedItem().toString();
        switch(selected_item) {
        case "Japan":
            // do something when japan is selected.
            break;

        case "China":
            // do something when China is selected.
            break;
        }
    }
}

如何使用 Java Netbeans 在 GUI 中执行选定的 ComboBox

how to Execute a selected ComboBox in GUI using Java Netbeans

java

user-interface

combobox

netbeans

execute