public UserLogin(Shell parentShell) {
super(parentShell);
setShellStyle(SWT.TITLE);
}
protected Control createDialogArea(Composite parent) {
parent.setBackground(SWTResourceManager.getColor(SWT.COLOR_WHITE));
Composite container = (Composite) super.createDialogArea(parent);
container.setLayout(null);
parent.getShell().setText("图书馆管理用户登录");
.....