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Property值發生變化說觸發ValueChangeEvent事件，可以通過ValueChangeListener監聽這個事件。

final TextField tf = new TextField("Name");        // Set the valuetf.setValue("The text field value"
 
);        // When the field value is edited by the usertf.addListener(new Property.ValueChangeListener() {    public void valueChange(ValueChangeEvent event) {        // Get the value and cast it to proper type        String value = (String) tf.getValue();                // Do something with it
 
        layout.addComponent(new Label(value));    }});

使用Property介面，一是實現Property介面，而是使用Vaadin內建的兩個Property介面實現：MethodProperty 主要用於Java Bean，而是ObjectProperty用於簡單的Java物件。

與Property介面關係緊密的還有兩個介面Property.Editor和Property.Viewer 可以用來顯示和編譯Property值，大部分的UI元件，尤其是Field元件實現了這兩個介面，因此Field元件可以直接繫結到Property物件，用來顯示或編輯Property資料。

下例使用Label 來顯示一個ObjectProperty 物件

// Have a data modelObjectProperty property =    new ObjectProperty("Hello", String.class);        // Have a component that implements ViewerLabel viewer = new Label();        // Bind it to the dataviewer.setPropertyDataSource(property);

// Have a data modelObjectProperty property =    new ObjectProperty("Hello", String.class);        // Have a component that implements ViewerTextField editor = new TextField("Edit Greeting");        // Bind it to the dataeditor.setPropertyDataSource(property);

前面說過所有Field元件也實現了Property介面，因此也可以把Field元件繫結到實現了Property.Viewer介面的UI元件，如Label。下例把一個Label繫結到一個TextField，因此Label顯示的內容會和TextField的值變化而變化。

Label viewer = new Label();viewer.setPropertyDataSource(editor); // The value shown in the viewer is updated immediately// after editing the value in the editor (once it// loses the focus)editor.setImmediate(true);

class MyProperty implements Property {    Integer data     = 0;    boolean readOnly = false;        // Return the data type of the model    public Class<?> getType() {        return Integer.class;    }    public Object getValue() {        return data;    }        // Override the default implementation in Object    @Override    public String toString() {        return Integer.toHexString(data);    }    public boolean isReadOnly() {        return readOnly;    }    public void setReadOnly(boolean newStatus) {        readOnly = newStatus;    }    public void setValue(Object newValue)            throws ReadOnlyException, ConversionException {        if (readOnly)            throw new ReadOnlyException();                    // Already the same type as the internal representation        if (newValue instanceof Integer)            data = (Integer) newValue;                // Conversion from a string is required        else if (newValue instanceof String)            try {                data = Integer.parseInt((String) newValue, 16);            } catch (NumberFormatException e) {                throw new ConversionException();            }        else             // Don't know how to convert any other types            throw new ConversionException();        // Reverse decode the hexadecimal value    }}        // Instantiate the property and set its dataMyProperty property = new MyProperty();property.setValue(42);        // Bind it to a componentfinal TextField tf = new TextField("Name", property);

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