Showing DoubleProperty up to two decimal places in TableView

问题

I'm having a problem showing a doubleProperty up until the second decimal.

A rough layout looks like this:

public static void main(String[] args) {
    private TableView<myType> myTable;
    private TableColumn<myType, Double> myCol;

public class myObject {
    .....
    DoubleProperty myDouble;
    ....

    public doubleProperty getPropertyMyDouble() {
        return myDouble;
    }

    public void setMyDouble(double d) {
        myDouble.set(d)
    }
}

And I fill the column with:

   ...
   myCol.setCellValueFactory(cellData ->cellData.getValue().getPropertyMyDouble().asObject());
   ...

Now my problem is this: If I leave the setMyDouble method the way it is, myCol is full of numbers with lots of decimals. I only want up to the second decimal.

What I tried doing is something like this:

public void setMyDouble(double d) {
        BigDecimal bd = new SimpleDecimalFormat("#.00")
        myDouble.set(Double.parseDouble(bd.format(d));
    }

Now this works in removing digits after the second decimal, but the problem is that if I have something like 12.00, because I need to convert to a double at the end (Since .set() takes a double) it turns 12.00 into a 12.0. However, I need to keep two decimal places all the time.

Is there any way to keep myDouble as a DoubleProperty (I'm doing this because it makes updating the table automatically after changes much easier) but present the data as in the "#.##" format?

I was thinking maybe doing something like adding an instance variable:

StringProperty myDoublePresent;

which would just take myDouble and turn it into a string and then present in the "#.##" format.

But I'd prefer a method where I can work directly with the DoubleProperty.

回答1:

Try

myCol.setCellValueFactory(cellData ->
     Bindings.format("%.2f", cellData.getValue().getPropertyMyDouble()));

回答2:

Following James_D suggestion in the accepted answer here is the general purpose solution allowing formatting of any column.

public class DecimalColumnFactory<S, T extends Number> implements Callback<TableColumn<S, T>, TableCell<S, T>> {

    private DecimalFormat format;

    public DecimalColumnFactory(DecimalFormat format) {
        super();
        this.format = format;
    }

    @Override
    public TableCell<S, T> call(TableColumn<S, T> param) {
        return new TableCell<S, T>() {

            @Override
            protected void updateItem(T item, boolean empty) {
                if (!empty && item != null) {
                    setText(format.format(item.doubleValue()));
                } else {
                    setText("");
                }
            }
        };
    }
}

this can be used by

theColumn.setCellFactory(new DecimalColumnFactory<>(new DecimalFormat("0.00")));

来源：https://stackoverflow.com/questions/31318989/showing-doubleproperty-up-to-two-decimal-places-in-tableview

标签

java

javafx