Question

我是Xamarin.iOS初学者。我也没有太多的iOS原生经验。我试图隐藏并显示包含UILabel和UITextField的UIView。虽然视图的hidden属性设置为true，但它仍占用屏幕空间。如何删除此空间？如果我尝试将宽度约束设置为0以隐藏它然后再将其设置回原始值以显示它，它就不起作用。它继续保持在0。

另一个问题 - 当切换开启和关闭其可见性时，视图是否会保留其状态和行为？

提前感谢所有帮助..

Answer 1

如果没有您的代码，很难说出解决方案。但是从你的问题我可以看到很少的解决方案，如：

您可以尝试更改主线程中的约束，更改约束后需要调用LayoutIfNeeded()

[Foundation.Export("layoutIfNeeded")] public virtual Void LayoutIfNeeded ()
除此之外，您可以使用horizontal UIStackView将UIView的宽度设为0，同时隐藏并在显示时返回原始状态。

Answer 2

即使您将控件的NSLayoutAnchor设置为true，它仍然存在，但是无法看到。因此，如果你的第二个控件的约束依赖于第一个，它就不会改变它的位置。

将其设置回原始值以显示它，它不起作用。它继续保持在0。

您使用哪种约束？

如果您使用//Define a field NSLayoutConstraint WidthConstraint = null; //When you want to modify the width, try to disable the previous one if (WidthConstraint != null) { WidthConstraint.Active = false; } WidthConstraint = Control.WidthAnchor.ConstraintEqualTo(0); WidthConstraint.Active = true;，则应在要修改之前禁用先前的约束。例如：

NSLayoutConstraint

如果您使用foreach (NSLayoutConstraint constraints in Control.Constraints) { if (constraints.FirstItem.IsEqual(Control) && constraints.FirstAttribute.Equals(NSLayoutAttribute.Width)) { constraints.Constant = 0; } }，则可以直接更改常量：

import requests, json, pprint
import urllib3
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

pagesize = 1000

api_url_base = "https://test/sepm/api/v1/"
authentication_url = "https://test/sepm/api/v1/identity/authenticate"

json_format = True


payload = {
 "username" : "test",
 "password" : "test",
 "domain" : ""}

headers = {"Content-Type":"application/json"}

r = requests.post(authentication_url, verify=False, headers=headers, 
data=json.dumps(payload))
api_token = (r.json()["token"])

headers = {'Content-Type': 'application/json', 'Authorization': 'Bearer 
{0}'.format(api_token)}


def get_info(url,params):
 api_url = url
 params = params
 response = requests.get(api_url, headers=headers,verify=False, 
params=params)
 if response.status_code == 200:
 return json.loads(response.content.decode('utf-8'))
 else:
 return response.status_code

def aggregate(endpoint_info,numberOfElements):
  itr =0
 while itr <= (numberOfElements-1):
 computerName=endpoints_info['content'][itr]['computerName']
 ipAddresses=endpoints_info['content'][itr]['ipAddresses'][0]
 logonUserName=endpoints_info['content'][itr]['logonUserName']
 lastUpdateTime=endpoints_info['content'][itr]['creationTime']
 agentVersion = endpoints_info['content'][itr]['agentVersion']
 print(computerName, ipAddresses, logonUserName, lastUpdateTime, a 
gentVersion)
 itr = itr+1




groups_url = '{0}groups'.format(api_url_base)
fingerprint_url = '{0}policy-objects/fingerprints'.format(api_url_base)
endpoints_url = '{0}computers?'.format(api_url_base)

total_pages = get_info(endpoints_url,{'pageSize':pagesize})['totalPages']


itr = 1
while itr <= total_pages:
 params = {'pageSize':pagesize, 'pageIndex':itr}
 endpoints_info = get_info(endpoints_url,params)
 numberOfElements = endpoints_info['numberOfElements']
 itr = itr +1
 if endpoints_info is not 200:

 aggregate(endpoints_info,numberOfElements)

 else:
 print('[!] Request Failed, {0}')

隐藏和显示Xamarin.iOS中的控件

2 个答案: