combobox | 易学教程

Retrieve a ComboBox counts and items by using SendMessage API

阅读更多关于 Retrieve a ComboBox counts and items by using SendMessage API

问题 I want to get a count and list of ComboBox control which is not mine so that I cannot modify the code. For example, controlling the target app can be done by using SendMessage API. But, how can I retrieve a whole list of the target control by hooking? 回答1: You can find a list of ComboBox control messages here: MSDN - ComboBox Control Messages PInvoke - CB_ Constants To get items count you need to use CB_GETCOUNT message and to get text of an item you can use CB_GETLBTEXT message. Example Here

Disable item inside combo box SAPUI5

阅读更多关于 Disable item inside combo box SAPUI5

问题 I have a combo box with, let's say, 2 items. one of the items has relevant data to report, and the other doesn't. How would I grey out the unwanted item in the combo box? I can grey out the entire combo box, but I'm not sure how to grey out items inside a combo box (this combo box is populated by an ODATA call). 回答1: You can set the items of the combo box to the disabled as follows: Want to disable the selected item from combo box list: this.getView().byId("idOfYourComboBox").getSelectedItem(

Disable item inside combo box SAPUI5

阅读更多关于 Disable item inside combo box SAPUI5

Cascading Combo box doesn't update 2nd box options

阅读更多关于 Cascading Combo box doesn't update 2nd box options

问题 I am using MS Access 2010 to store records about audits that take place at our hospital. I am trying to create a form where it will filter the audits according to the drop down options selected. I want the Specialty combo boxes to cascade from Directorate, so if I select "Family and Public Health" Directorate, only the Specialties that are within that Directorate appear in the combo box below. My ComboDirectorate Row Source is SELECT [tblDirectorate].[Directorate Key], [tblDirectorate].

Eliminating multiple Elseif statements

阅读更多关于 Eliminating multiple Elseif statements

问题 Im trying to keep my code clean and especially using Comboboxes in userforms there can be a lot of if Elseif statements. There should be an easier way to not have multiple pages of code for just one combobox is there? Example of how it is done now: Sub Example() Dim Variable as String If Combobox1.Value = "Option1" Then Variable = "Name1" Elseif Combobox1.Value = "Option2" Then Variable = "Name2" Elseif Combobox1.Value = "Option3" Then Variable = "Name3" Elseif Combobox1.Value = "Option4"

CSS Custom combobox issue

阅读更多关于 CSS Custom combobox issue

问题 I need a custom combo box. So, I implemented with ul . The problem is I can't get combo box list opens on top by clicking the button . While showing ul , it moves button to bottom of the webpage. Code: ul{ width: 100px; background-color: rgb(224, 224, 224); border-radius: 4px; border: 1px solid black; padding: 0; margin: 0; } ul li{ list-style: none; cursor: pointer; padding: 4px 10px; } li:hover{ background-color: white; } div{ width: 100%; height: 40px; background-color: bisque; } section{

Strange behaviour (or bug?) with ComboBox in WPF when changing DataContext and having bound ItemsSource and SelectedItem

阅读更多关于 Strange behaviour (or bug?) with ComboBox in WPF when changing DataContext and having bound ItemsSource and SelectedItem

问题 I'm trying to debug a strange error in a combobox bound to an itemssource and selecteditem. It's driving me crazy. The problem arise when changing selected tabitem in which the combobox exists. (Actually it's only when changing the DataContext of the ComboBox). The SelectedItem-binding has a custom validationrule to give error if value is null. The problem is that wpf calls my custom rule when switching tabitems (DataContext) and tries to validate a value of null, even though the selecteditem

How to use a <ComboboxSelected> virtual event with tkinter

阅读更多关于 How to use a virtual event with tkinter

问题 I am using a tkk.Combobox themed widget in Python 3.5.2. I want an action to happen when a value is selected. In the Python docs, it says: The combobox widgets generates a <<ComboboxSelected>> virtual event when the user selects an element from the list of values. Here on the Stack, there are a number of answers (1, 2, etc) that show how to bind the event: cbox.bind("<<ComboboxSelected>>", function) However, I can't make it work. Here's a very simple example demonstrating my non-functioning

WPF之路——实现自定义虚拟容器(实现VirtualizingPanel)

阅读更多关于 WPF之路——实现自定义虚拟容器(实现VirtualizingPanel)

原文: WPF之路——实现自定义虚拟容器(实现VirtualizingPanel) 源码下载地址： http://download.csdn.net/detail/qianshen88/6618033 在WPF应用程序开发过程中，大数据量的数据展现通常都要考虑性能问题。有下面一种常见的情况:原始数据源数据量很大，但是某一时刻数据容器中的可见元素个数是有限的，剩余大多数元素都处于不可见状态，如果一次性将所有的数据元素都渲染出来则会非常的消耗性能。因而可以考虑只渲染当前可视区域内的元素，当可视区域内的元素需要发生改变时，再渲染即将展现的元素，最后将不再需要展现的元素清除掉，这样可以大大提高性能。在WPF中System.Windows.Controls命名空间下的 VirtualizingStackPanel 可以实现数据展现的虚拟化功能，ListBox的默认元素展现容器就是它。但有时 VirtualizingStackPanel 的布局并不能满足我们的实际需要，此时就需要实现自定义布局的虚拟容器了。本文将简单介绍容器自定义布局，然后介绍实现虚拟容器的基本原理，最后给出一个虚拟化分页容器的演示程序。一、WPF中自定义布局（已了解容器自定义布局的朋友可略过此节）通常实现一个自定义布局的容器，需要继承System.Windows.Controls.Panel, 并重写下面两个方法:

深入浅出WPF之控件与布局

阅读更多关于深入浅出WPF之控件与布局

WPF中的六大控件类型 1.布局控件：可以容纳多个控件或者其它布局控件，例如Grid,StackPanel,DockPanel，父类：Panel。 2.内容控件：只能容纳一个其它控件或者布局控件作为它的内容。Window,Button等控件属于此类。父类：ContentControl. 3.带标题内容控件：相当于一个内容控件，但可以加一个标题，标题部分也可以容纳一个控件或者一个布局控件。GroupBox,TabItem.父类：HeaderedContentControl. 4.条目控件：可以显示一列数据，它们的类型一般情况下相同。ListBox,ComboBox。父类：ItemsControl 5.带标题条目控件：相当于一个条目控件加上一个标题显示区。TreeViewItem,MenuItem都属于此类控件。父类：HeaderedItemsControl. 6.特殊内容控件：比如TextBox容纳的是字符串，TextBlock可以容纳可自由控制格式的文本Image容纳图片类型数据 UI布局 1.Grid：网格。可以自定义和列并通过行列的数量，行高和列宽来调整控件的布局，类似于HTML中的Table.适合的场景有： UI布局的大框架的设计，大量UI元素需要成行或者成列对齐的情况，UI整体尺寸发生变化时，元素需要保持固有的宽高比例。 2.StackPanel：栈式面板