java - 带有自定义对象的 FIlteredList

Question

我有一个名为“MyObject”的类，如下所示:

public class MyObject {
    private int type;
    private byte[] file;
    private String fileName;
    private String titolo;

     public MyObject(String tit, int t, byte[] b, String name)
     {    
          titolo= tit;
          type = t;
          file = b;
          fileName = name;
     }


     int getType(){
         return type;
     }
     String getfileName(){
         return fileName;
     }
     byte[] getFile(){
         return file;
     }
     String getTitolo(){
         return titolo;
     }
}

我已经开发了如何加载列表的元素，现在，我想用 FilterList 进行过滤。我想按“titolo”和“fileName”进行过滤。这是我现在正在工作的另一个类(class):

public class ContentTab extends VBox{
    Label allegati;
    TextField inseriscitesto;
    ListView<MyObject> view;
    ObservableList<MyObject> data;

    public ContentTab(int width){

         setPadding(new Insets(20));
         setSpacing(10);
         allegati = new Label("Allegati alla lezione");
         allegati.setFont(Font.font("Verdana", 13));
          inseriscitesto = new TextField("");
         data = FXCollections.observableArrayList();

         view = new ListView<MyObject>(data);

         view.setStyle("-fx-background-color: transparent;");
        setPrefWidth(width);
        getChildren().addAll(allegati,inseriscitesto, view);


    }

    public void loadElement(List<MyObject> element){

        for(int i = 0; i< element.size(); i++)
            data.add(element.get(i));

                   view.setCellFactory(new Callback<ListView<MyObject>, ListCell<MyObject>>() {

            @Override
            public ListCell<MyObject> call(ListView<MyObject> arg0) {
                return new ListCell<MyObject>() {

                    @Override
                    protected void updateItem(MyObject item, boolean bln) {
                        super.updateItem(item, bln);
                        if (item != null) {
                            setStyle("-fx-background-color: transparent;");
                            VBox vBox = new VBox(new Text(item.getTitolo()), new Text(item.getfileName()));
                            ImageView placeHolder;

                            if(item.getType() == myMediaType.PDF){
                                placeHolder= new ImageView(new Image("img/pdf.jpg"));
                            placeHolder.setScaleX(0.5);
                            }
                            else
                                placeHolder= new ImageView(new Image("img/video.jpg"));
                            HBox hBox = new HBox(placeHolder, vBox);

                            hBox.setSpacing(10);
                            setGraphic(hBox);
                        }
                    }

                };
            }

        });
    }

    public void FilterElement(List<MyObject> element){

    FilteredList<MyObject> filteredData = new FilteredList<>(data, s -> true);

    inseriscitesto.textProperty().addListener(obs->{
        String filter = inseriscitesto.getText(); 
        if(filter == null || filter.length() == 0) {
            filteredData.setPredicate(s -> true);
        }
        else {
            filteredData.setPredicate(s -> ((List<MyObject>) s.).contains(filter));
        }
    });


    } 

所以，我的问题是，如何在 FilterElement 方法中按 MyObject 的属性进行过滤？

如果我不清楚或代码太多，请提前抱歉，但我认为我只是解释了问题所必需的。

Answer 1

您应该将 ListView 项设置为过滤列表，并保留对它的引用，并随着文本更改而更改其谓词:

public class ContentTab extends VBox{
    Label allegati;
    TextField inseriscitesto;
    ListView<MyObject> view;

    public ContentTab(int width){

         setPadding(new Insets(20));
         setSpacing(10);
         allegati = new Label("Allegati alla lezione");
         allegati.setFont(Font.font("Verdana", 13));
          inseriscitesto = new TextField("");
         FilteredList<MyObject> filteredData = new FilteredList(FXCollections.observableArrayList(), s -> true);

         view = new ListView<MyObject>(filteredDate);
        inseriscitesto.textProperty().addListener(obs->{
            String filter = inseriscitesto.getText(); 
            if(filter == null || filter.length() == 0) {
                filteredData.setPredicate(s -> true);
            }
            else {
                filteredData.setPredicate(s -> s.getTitolo().contains(filter));
            }
        });

         view.setStyle("-fx-background-color: transparent;");
        setPrefWidth(width);
        getChildren().addAll(allegati,inseriscitesto, view);

    }

另请注意，您的谓词应该是一个接受 MyObject 的函数，如果应该显示，则返回 true，如果应该显示，则返回 false应该被过滤掉。我猜您想检查 Titolo 属性是否包含过滤器文本，但您可能想将其更改为另一个属性。