Question

此代码允许用户仅键入某些字符：

var companies = [
    {
        id: 1,
        name: 'Google',
        link: 'http://google.com/'
    },
    {
        id: 2,
        name: 'Microsoft',
        link: 'http://microsoft.com/'
    },
    {
        id: 3,
        name: 'Apple',
        link: 'http://apple.com'
    }
];



var tbl = document.createElement('table');
var input = document.getElementById('input');
var thead = document.createElement("thead");
var tbody = document.createElement("tbody");

var tr_head = document.createElement("tr");

var th_id = document.createElement("th");
var th_name = document.createElement("th");
var th_link = document.createElement("th");

th_id.textContent = "Id";
th_name.textContent = "Name";
th_link.textContent = "link";


tr_head.appendChild(th_id);
tr_head.appendChild(th_name);
tr_head.appendChild(th_link);

thead.appendChild(tr_head);

for(var i = 0;  i < companies.length; i++) {
    var tr_body = document.createElement("tr");

    var td_id = document.createElement("td");
    var td_name = document.createElement("td");
    var td_link = document.createElement("td");

    // var id = companies[i].id;
    // var name = companies[i].name;
    // var link = companies[i].link;

    td_id.textContent = companies[i].id;
    td_name.textContent = companies[i].name;
    td_link.textContent = companies[i].link;

    tr_body.appendChild(td_id);
    tr_body.appendChild(td_name);
    tr_body.appendChild(td_link);

    tbody.appendChild(tr_body);
}

tbl.appendChild(thead);
tbl.appendChild(tbody);

console.log(tbl);

// input.appendChild(tbl);

我怎样才能使它只允许一个名为＆＃34; txtField1＆＃34;的文本字段？

Answer 1

您可以检查textField是否是shouldChangeCharactersInRange方法中当前选择的那个，因为您可以在此方法的参数中看到，您可以访问与当前textField对应的属性textField您正在选择，所以请在开头查看：

if texField == txtField1 {
  // Do your stuff 
 } else {
 // Do something else 
}

Answer 2

为文本字段中对其唯一的标记指定值（例如，1）。

txtField1.tag = 1

然后，像这样更新你的方法：

func textField(
    textField: UITextField,
    shouldChangeCharactersInRange range: NSRange,
                                  replacementString string: String)
    -> Bool
{
    if textField.tag == 1 {
        let set = NSCharacterSet(charactersInString: allowedChars)

        let filtered = string
            .componentsSeparatedByCharactersInSet(set)
            .joinWithSeparator("")
        return filtered != string
    }

    return true
}

你也可以省略;在斯威夫特。

如何为某个文本字段创建函数？

2 个答案: