我希望用户只能写数字和空格。
我如何在 SWT 中做到这一点?
最佳答案
使用 VerifyListener 并根据用户输入拒绝字符。
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.VerifyEvent;
import org.eclipse.swt.events.VerifyListener;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class Test {
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
final Text text = new Text(shell, SWT.BORDER);
text.addVerifyListener(new VerifyListener() {
@Override
public void verifyText(VerifyEvent e) {
// allows cut (CTRL + x)
if (e.text.isEmpty()) {
e.doit = true;
} else if (e.keyCode == SWT.ARROW_LEFT ||
e.keyCode == SWT.ARROW_RIGHT ||
e.keyCode == SWT.BS ||
e.keyCode == SWT.DEL ||
e.keyCode == SWT.CTRL ||
e.keyCode == SWT.SHIFT) {
e.doit = true;
} else {
boolean allow = false;
for (int i = 0; i < e.text.length(); i++) {
char c = e.text.charAt(i);
allow = Character.isDigit(c) || Character.isWhitespace(c);
if ( ! allow ) {
break;
}
}
e.doit = allow;
}
}
});
text.setSize(200, 20);
shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
}
}
关于java - 防止用户在 SWT 的文本字段中输入字符,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4346002/