code: function alert(title, content, callback, type) {
    const opt = defaultOption.alert;
    const argLen = arguments.length;
    if (argLen === 1) {
      content = title;
      title = null;
    }
    if (argLen === 2) {
      if (typeof content === 'function') {
        callback = content;
        content = title;
        title = null;
      }
    }
    title = title || opt.title;
    if (opt.actions[0]) {
      opt.actions[0].onPress = callback;
    }
    tip(title, content, opt.actions, type);
  }
docs: 提醒
  Dialog.alert('内容')
  Dialog.alert('内容', callback)
  Dialog.alert('标题', '内容')
  Dialog.alert('标题', '内容', callback)
  @param {String} title
  @param {String/Element} content