java - 如何过滤退格键盘输入

Question

我有这段代码，当按下另一个数字键时会发出一条消息:

txtValueOfClause.addEventFilter(KeyEvent.KEY_TYPED, new EventHandler<KeyEvent>() {
            @Override
            public void handle(KeyEvent t) {
                char ar[] = t.getCharacter().toCharArray();
                char ch = ar[t.getCharacter().toCharArray().length - 1];
                if (!(ch >= '0' && ch <= '9')) {
                    System.out.println("The char you entered is not a number");
                    t.consume();
                }
            }
        });

现在，如果我按了错误的按钮并按退格键将其删除，我也会收到此错误消息。 如何在 if 语句中添加退格输入？

Answer 1

我找到了答案:

txtValueOfClause.addEventFilter(KeyEvent.KEY_TYPED, new EventHandler<KeyEvent>() {
            @Override
            public void handle(KeyEvent t) {
                char ar[] = t.getCharacter().toCharArray();
                char ch = ar[t.getCharacter().toCharArray().length - 1];
                int codeBackSpace = ch;
                if (!(ch >= '0' && ch <= '9') && codeBackSpace!=8) {

                    System.out.println("The char you entered is not a number");
                    t.consume();
                }
            }
        });