此错误消息...

invalid element state: Element must be user-editable in order to clear it.

...表示所标识的元素不是处于用户可编辑状态，无法调用clear()方法.

...implies that the element identified was not in a user-editable state to invoke clear() method.

要在带有 Angular 元素的下拉列表中插入日期，有两种方法:

To insert a date with in a dropdown-toggle with an Angular element there are two approaches:

• 您可以在日历上click()并使用sendKeys()
插入日期
• 或者您可以使用executeScript()调用removeAttribute() 只读属性.

• Either you can click() on the calendar and insert a date using sendKeys()
• Or you can use executeScript() to invoke removeAttribute() the readonly attribute.

但是，按照您共享的HTML，在

However, as per the HTML you have shared it seems the element which gets populated with the date string i.e. 2019/11/21 is not readily available within the HTML DOM. So we can infer that the following element gets added to the DOM Tree as a result of interaction with other WebElements which is as follows:

<p ng-if="displayEndDate" class="ng-binding ng-scope">2019/11/21</p>

因此***的方法是

• 首先在HTML中的 WebDriverWait 中容易使用的元素上调用click().
• 接下来在新创建的元素 WebDriverWait 上调用sendKeys().

• 代码块:

• First to invoke click() on the element readily available within the HTML inducing WebDriverWait.
• Next to invoke sendKeys() on the newly created element WebDriverWait.

• Code Block:

//element -> myclass.SetDateByXpath("//a[@class='dropdown-toggle' and @id='enddate-dropdown']"
// observe the change in the ^^^ xpath ^^^
//value -> myclass.GetDate("yyyy/MM/dd", mydate));

public void SetDateByXpath(String element, String value)
{
    WebElement webElement = ExplicitWaitOnElement(By.xpath(element));       
    webElement.click();
    WebElement webElement_new = ExplicitWaitOnElement(By.xpath("//a[@class='dropdown-toggle' and @id='enddate-dropdown']//p[@class='ng-binding ng-scope' and @ng-if='displayEndDate']"));
    webElement_new.clear();
    webElement_new.sendKeys(value);
}

您可以在以下位置找到相关讨论:

You can find a relevant discussion in:

• InvalidElementStateException无效的元素状态:元素必须使用Selenium Python发送文本时，用户可以对其进行编辑以清除它"错误