如何将可见绑定与单选按钮可观察参数一起使用？
当此页面呈现时，会选择正确的单选按钮，但是当选择“sendemail”或“sms”单选按钮值时，应该会出现附加输入，对吧？
$(function () {
var rbViewModel = {
qrType: ko.observable('plaintext')
};
ko.applyBindings(rbViewModel);
});
然后是我的单选按钮
<input type="radio" name="txtType" value="plaintext" data-bind="checked: qrType" />Plaintext
<input type="radio" name="txtType" value="sendemail" data-bind="checked: qrType" />Send E-mail
<input type="radio" name="txtType" value="sms" data-bind="checked: qrType" />SMS
和我的输入：
<div data-bind="visible: qrType == 'sendemail'"><input type="text" id="txtEmailSubject" placeholder="E-mail subject" /></div>
<div data-bind="visible: qrType == 'sendemail'"><input type="text" id="txtEmailBody" placeholder="E-mail body" /></div>
<div data-bind="visible: qrType == 'sms'"><input type="text" id="txtSmsMsg" placeholder="SMS body" /></div>
div 元素上的属性是否有问题？我认为函数可以在每个 KnockoutJS 文档 的可见绑定中使用，如下所示：
data-bind="visible: qrType=='sendemail'"
The correct radio button is selected when this page renders, but the additional inputs should appear when either "sendemail" or "sms" radio button values are selected, right?
$(function () {
var rbViewModel = {
qrType: ko.observable('plaintext')
};
ko.applyBindings(rbViewModel);
});
Then my radio buttons
<input type="radio" name="txtType" value="plaintext" data-bind="checked: qrType" />Plaintext
<input type="radio" name="txtType" value="sendemail" data-bind="checked: qrType" />Send E-mail
<input type="radio" name="txtType" value="sms" data-bind="checked: qrType" />SMS
And my inputs:
<div data-bind="visible: qrType == 'sendemail'"><input type="text" id="txtEmailSubject" placeholder="E-mail subject" /></div>
<div data-bind="visible: qrType == 'sendemail'"><input type="text" id="txtEmailBody" placeholder="E-mail body" /></div>
<div data-bind="visible: qrType == 'sms'"><input type="text" id="txtSmsMsg" placeholder="SMS body" /></div>
Is there something wrong with the attribute on the div elements? I thought functions were able to be used in the visible bindings per KnockoutJS documentation, like this:
data-bind="visible: qrType=='sendemail'"
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当您在数据绑定属性的表达式中使用可观察量时，需要使用 () 引用它。
它们需要看起来像：
visible: qrType() === 'sendemail'When you use an observable in an expression in a data-bind attribute, you need to reference it with ().
They would need to look like:
visible: qrType() === 'sendemail'