java 从 TextField 使用 JavaFX KeyTyped 事件
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Consume JavaFX KeyTyped event from TextField
提问by cefeboru
I'm trying to validate a TextField, where I only want to allow numbers on the TextField. My code looks like this:
我正在尝试验证一个 TextField，我只想在 TextField 上允许数字。我的代码如下所示：
public void handle(KeyEvent evt) {
String character = evt.getCharacter();
if(!character.equals("1")) {
JOptionPane.showMessageDialog(null,evt.getCharacter());
evt.consume();
}
}
This doesn't consume the event :( Is this a bug? Is there another way to do this?
这不会消耗事件 :( 这是一个错误吗？还有其他方法可以做到这一点吗？
回答by Anshul Parashar
try this its worked..
试试这个它的工作..
txtMobile.addEventFilter(KeyEvent.KEY_TYPED, new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent event) {
String character=event.getCharacter();
if(!valid.checkNumeric(character))
event.consume();
}});
and the function for numeric...
和数字函数...
public boolean checkNumeric(String value) {
String number=value.replaceAll("\s+","");
for(int j = 0 ; j<number.length();j++){
if(!(((int)number.charAt(j)>=47 && (int)number.charAt(j)<=57)))
{
return false;
}
}
return true;
}
回答by Uwe
Starting with JavaFX 8u40, the best way to restrict the input of a text field is to set a TextFormatteron the text field. See this answerfor details. No need to add event filters or consume events manually.
从 JavaFX 8u40 开始，限制文本字段输入的最佳方法是在文本字段上设置TextFormatter。有关详细信息，请参阅此答案。无需手动添加事件过滤器或使用事件。
回答by sarcan
I think consuming the key events is the wrong approach to this. An arguably simpler and less invasive way to filter the input is to install a listener on the text property and revert it if needed:
我认为使用关键事件是错误的方法。一种可以说更简单、侵入性更小的过滤输入的方法是在 text 属性上安装一个监听器，并在需要时恢复它：
public class Test extends Application {
@Override
public void start(final Stage stage) throws Exception {
final Pattern wholeNumberPattern = Pattern.compile("\d*");
final TextField tf = new TextField();
tf.textProperty().addListener(new ChangeListener<String>() {
public void changed(final ObservableValue<? extends String> observableValue, final String oldValue,
final String newValue) {
if (!wholeNumberPattern.matcher(newValue).matches())
tf.setText(oldValue);
}
});
stage.setScene(new Scene(tf));
stage.show();
}
public static void main(String[] args) {
System.out.println(com.sun.javafx.runtime.VersionInfo.getRuntimeVersion());
Application.launch(args);
}
}
