从选定的组合框 javafx 中设置文本

Question

我是 JavaFX 的初学者，当我想要组合框的 setTextfield 时我觉得很难我有 2 个文件：控制器和实现

 //controller
    @FXML
    public void txtguru(KeyEvent event){
        ArrayList<String>tguru=crud.textguru((String)cmbmapel.getValue());
        txtguru.setText(tguru.toString());
    }

//implement
@Override
    public ArrayList<String> textguru(String a) {
        ArrayList<String>guru=new ArrayList<>();
        try {
            sql="select idguru from mapel where nmmapel like '%"+a+"%'";
            rs=con.connect().createStatement().executeQuery(sql);
            while(rs.next()){
                modelnilai m=new modelnilai();
                m.setguru(rs.getString("idguru"));
            }
        } catch (Exception e) {
            Logger.getLogger(implementnilai.class.getName()).log(Level.SEVERE, null,e);
        }
        return guru;
    }

Answer 1

tguru 变量始终为空，因为您没有在 textguru 方法中将新获取的 idguru 值添加到 guru 中。 （听起来像绕口令是的:)）。将它们添加为：

@Override
public ArrayList<String> textguru(String a) {
    ArrayList<String>guru=new ArrayList<>();
    try {
        sql="select idguru from mapel where nmmapel like '%"+a+"%'";
        rs=con.connect().createStatement().executeQuery(sql);
        while(rs.next()){
            String idguru = rs.getString("idguru");
            modelnilai m=new modelnilai();
            m.setguru(idguru);
            // Note that you are not using the modelnilai object above
            guru.add(idguru);
        }
    } catch (Exception e) {
        Logger.getLogger(implementnilai.class.getName()).log(Level.SEVERE, null,e);
    }
    return guru;
}