.net – 从多个动态图片框中更改图像

VB 前端之家
前端之家收集整理的这篇文章主要介绍了.net – 从多个动态图片框中更改图像，前端之家小编觉得挺不错的，现在分享给大家，也给大家做个参考。
我正在使用带有状态图像的VB.NET制作联系人列表.
我正在从MSsql加载这个列表但是当我重新加载列表时它会闪烁.

此列表是一个带有动态创建的图片框和标签的TableLayoutPanel.

我的问题是：

当您重新加载我的联系人而不是重新加载整个列表时,如何在动态图片框中更改我的图像.

我创建表的代码：

  1. While UserData.Read
  2.  
  3.     If UserData("Status").ToString = "Online" Then
  4.  
  5.         If UserData("NieuwBericht").ToString = "Ja" Then
  6.  
  7.             Dim newPictureBox As New PictureBox
  8.             newPictureBox.Image = My.Resources.greenchat
  9.             newPictureBox.Visible = True
  10.             newPictureBox.Width = 30
  11.             newPictureBox.Height = 30
  12.             newPictureBox.SizeMode = PictureBoxSizeMode.Zoom
  13.             newPictureBox.Name = UserData("Username").ToString
  14.             ChatContactList.Controls.Add(newPictureBox)
  15.  
  16.             Dim newPictureBox2 As New PictureBox
  17.             newPictureBox2.Image = My.Resources.greenbubblechat
  18.             newPictureBox2.Visible = True
  19.             newPictureBox2.Width = 30
  20.             newPictureBox2.Height = 30
  21.             newPictureBox2.SizeMode = PictureBoxSizeMode.Zoom
  22.             newPictureBox2.Name = UserData("Username").ToString
  23.             ChatContactList.Controls.Add(newPictureBox2)
  24.  
  25.             Dim newLabel As New Label
  26.             AddHandler newLabel.Click,AddressOf ChatBox
  27.             newLabel.Text = UserData("Voornaam").ToString & " " & UserData("Achternaam").ToString
  28.             newLabel.Name = UserData("Username").ToString
  29.             newLabel.Font = New Font("Microsoft sans serif",12)
  30.             newLabel.Dock = DockStyle.Fill
  31.             newLabel.TextAlign = ContentAlignment.MiddleLeft
  32.             newLabel.Visible = True
  33.             ChatContactList.Controls.Add(newLabel)
  34.  
  35.         ElseIf UserData("NieuwBericht").ToString = "Nee" Then
  36.  
  37.             Dim newPictureBox As New PictureBox
  38.             newPictureBox.Image = My.Resources.greenchat
  39.             newPictureBox.Visible = True
  40.             newPictureBox.Width = 30
  41.             newPictureBox.Height = 30
  42.             newPictureBox.SizeMode = PictureBoxSizeMode.Zoom
  43.             newPictureBox.Name = UserData("Username").ToString
  44.             ChatContactList.Controls.Add(newPictureBox)
  45.  
  46.             Dim newPictureBox2 As New PictureBox
  47.             newPictureBox2.Image = My.Resources.greybubblechat
  48.             newPictureBox2.Visible = True
  49.             newPictureBox2.Width = 30
  50.             newPictureBox2.Height = 30
  51.             newPictureBox2.SizeMode = PictureBoxSizeMode.Zoom
  52.             newPictureBox2.Name = UserData("Username").ToString
  53.             ChatContactList.Controls.Add(newPictureBox2)
  54.  
  55.             Dim newLabel As New Label
  56.             AddHandler newLabel.Click,12)
  57.             newLabel.Dock = DockStyle.Fill
  58.             newLabel.TextAlign = ContentAlignment.MiddleLeft
  59.             newLabel.Visible = True
  60.             ChatContactList.Controls.Add(newLabel)
  61.  
  62.         End If
  63.  
  64.     ElseIf UserData("Status").ToString = "Afwezig" Then
  65.  
  66.         If UserData("NieuwBericht").ToString = "Ja" Then
  67.  
  68.             Dim newPictureBox As New PictureBox
  69.             newPictureBox.Image = My.Resources.orangechat
  70.             newPictureBox.Visible = True
  71.             newPictureBox.Width = 30
  72.             newPictureBox.Height = 30
  73.             newPictureBox.SizeMode = PictureBoxSizeMode.Zoom
  74.             newPictureBox.Name = UserData("Username").ToString
  75.             ChatContactList.Controls.Add(newPictureBox)
  76.  
  77.             Dim newPictureBox2 As New PictureBox
  78.             newPictureBox2.Image = My.Resources.greenbubblechat
  79.             newPictureBox2.Visible = True
  80.             newPictureBox2.Width = 30
  81.             newPictureBox2.Height = 30
  82.             newPictureBox2.SizeMode = PictureBoxSizeMode.Zoom
  83.             newPictureBox2.Name = UserData("Username").ToString
  84.             ChatContactList.Controls.Add(newPictureBox2)
  85.  
  86.             Dim newLabel As New Label
  87.             AddHandler newLabel.Click,12)
  88.             newLabel.Dock = DockStyle.Fill
  89.             newLabel.TextAlign = ContentAlignment.MiddleLeft
  90.             newLabel.Visible = True
  91.             ChatContactList.Controls.Add(newLabel)
  92.  
  93.         ElseIf UserData("NieuwBericht").ToString = "Nee" Then
  94.  
  95.             Dim newPictureBox As New PictureBox
  96.             newPictureBox.Image = My.Resources.orangechat
  97.             newPictureBox.Visible = True
  98.             newPictureBox.Width = 30
  99.             newPictureBox.Height = 30
  100.             newPictureBox.SizeMode = PictureBoxSizeMode.Zoom
  101.             newPictureBox.Name = UserData("Username").ToString
  102.             ChatContactList.Controls.Add(newPictureBox)
  103.  
  104.             Dim newPictureBox2 As New PictureBox
  105.             newPictureBox2.Image = My.Resources.greybubblechat
  106.             newPictureBox2.Visible = True
  107.             newPictureBox2.Width = 30
  108.             newPictureBox2.Height = 30
  109.             newPictureBox2.SizeMode = PictureBoxSizeMode.Zoom
  110.             newPictureBox2.Name = UserData("Username").ToString
  111.             ChatContactList.Controls.Add(newPictureBox2)
  112.  
  113.             Dim newLabel As New Label
  114.             AddHandler newLabel.Click,12)
  115.             newLabel.Dock = DockStyle.Fill
  116.             newLabel.TextAlign = ContentAlignment.MiddleLeft
  117.             newLabel.Visible = True
  118.             ChatContactList.Controls.Add(newLabel)
  119.  
  120.         End If
  121.  
  122.     ElseIf UserData("Status").ToString = "Offline" Then
  123.  
  124.         If UserData("NieuwBericht").ToString = "Ja" Then
  125.  
  126.             Dim newPictureBox As New PictureBox
  127.             newPictureBox.Image = My.Resources.redchat
  128.             newPictureBox.Visible = True
  129.             newPictureBox.Width = 30
  130.             newPictureBox.Height = 30
  131.             newPictureBox.SizeMode = PictureBoxSizeMode.Zoom
  132.             newPictureBox.Name = UserData("Username").ToString
  133.             ChatContactList.Controls.Add(newPictureBox)
  134.  
  135.             Dim newPictureBox2 As New PictureBox
  136.             newPictureBox2.Image = My.Resources.greenbubblechat
  137.             newPictureBox2.Visible = True
  138.             newPictureBox2.Width = 30
  139.             newPictureBox2.Height = 30
  140.             newPictureBox2.SizeMode = PictureBoxSizeMode.Zoom
  141.             newPictureBox2.Name = UserData("Username").ToString
  142.             ChatContactList.Controls.Add(newPictureBox2)
  143.  
  144.             Dim newLabel As New Label
  145.             AddHandler newLabel.Click,12)
  146.             newLabel.Dock = DockStyle.Fill
  147.             newLabel.TextAlign = ContentAlignment.MiddleLeft
  148.             newLabel.Visible = True
  149.             ChatContactList.Controls.Add(newLabel)
  150.  
  151.         ElseIf UserData("NieuwBericht").ToString = "Nee" Then
  152.  
  153.             Dim newPictureBox As New PictureBox
  154.             newPictureBox.Image = My.Resources.redchat
  155.             newPictureBox.Visible = True
  156.             newPictureBox.Width = 30
  157.             newPictureBox.Height = 30
  158.             newPictureBox.SizeMode = PictureBoxSizeMode.Zoom
  159.             newPictureBox.Name = UserData("Username").ToString
  160.             ChatContactList.Controls.Add(newPictureBox)
  161.  
  162.             Dim newPictureBox2 As New PictureBox
  163.             newPictureBox2.Image = My.Resources.greybubblechat
  164.             newPictureBox2.Visible = True
  165.             newPictureBox2.Width = 30
  166.             newPictureBox2.Height = 30
  167.             newPictureBox2.SizeMode = PictureBoxSizeMode.Zoom
  168.             newPictureBox2.Name = UserData("Username").ToString
  169.             ChatContactList.Controls.Add(newPictureBox2)
  170.  
  171.             Dim newLabel As New Label
  172.             AddHandler newLabel.Click,12)
  173.             newLabel.Dock = DockStyle.Fill
  174.             newLabel.TextAlign = ContentAlignment.MiddleLeft
  175.             newLabel.Visible = True
  176.             ChatContactList.Controls.Add(newLabel)
  177.  
  178.         End If
  179.  
  180.     End If
  181.  
  182. End While

我的联系人名单的图片

UserControl有点像子表单.它是各种控件的容器,它们共同起作用或代表某个逻辑单元.在这种情况下,它将是一些用户状态(属性)的可视化表示.您可以将它们放在一个UC上,并封装大部分代码来管理它们,而不是创建和管理单个控件.

在Solution Explorer窗口中,右键单击,选择Add,然后选择UserControl.我添加了一个TableLayoutPanel,2个PictureBoxes和一个Label(当然所有都有正确的名称).还有一个ImageList,可快速抓取您的图像：

仅此一项就可以替换许多代码行来创建新控件,然后一遍又一遍地设置相同的属性.要使它们充当逻辑对象,您可以添加抽象选择图像的细节等属性：

  1. Public Class Chatter
  2.  
  3.     Public Enum ChatStatus
  4.         Unknown
  5.         Online
  6.         Away
  7.         Offline
  8.     End Enum
  9.  
  10.     Public Enum ChatMsgStatus
  11.         Undefined      ' kludge to force the initial state
  12.         Unknown
  13.         [New]
  14.         Read
  15.     End Enum
  16.  
  17.     ' one set of images for all chatter instances
  18.     Private Shared Imgs As Image()
  19.  
  20.     Public Property ChatId As Int32         ' or guid?
  21.  
  22.     Private chName As String = ""
  23.     Public ReadOnly Property ChatName As String
  24.         Get
  25.             Return chName
  26.         End Get
  27.     End Property
  28.  
  29.     Private mStatus As ChatMsgStatus = ChatMsgStatus.Undefined
  30.     Public Property MsgStatus As ChatMsgStatus
  31.         Get
  32.             Return mStatus
  33.         End Get
  34.         Set(value As ChatMsgStatus)
  35.             If (value <> mStatus) Then
  36.                 Select Case value
  37.                     Case ChatMsgStatus.New
  38.                         pbMStatus.Image = Imgs(3) 
  39.                     Case ChatMsgStatus.Read
  40.                         pbMStatus.Image = Imgs(4)
  41.                     Case Else
  42.                         pbMStatus.Image = Imgs(4)
  43.                 End Select
  44.             End If
  45.             mStatus = value
  46.         End Set
  47.     End Property
  48.  
  49.     Private chStatus As ChatStatus = ChatStatus.Unknown
  50.     Public Property Status As ChatStatus
  51.         Get
  52.             Return chStatus
  53.         End Get
  54.         Set(value As ChatStatus)
  55.             If value <> chStatus Then
  56.                 Select Case value
  57.                     Case ChatStatus.Online
  58.                         pbUStatus.Image = Imgs(0)
  59.                     Case ChatStatus.Away
  60.                         pbUStatus.Image = Imgs(1)
  61.                     Case ChatStatus.Offline
  62.                         pbUStatus.Image = Imgs(2)
  63.                     Case Else
  64.                 End Select
  65.             End If
  66.             chStatus = value
  67.         End Set
  68.     End Property
  69.  
  70.     Public Sub New()
  71.         ' This call is required by the designer.
  72.         InitializeComponent()
  73.  
  74.         If Imgs Is Nothing Then
  75.             Imgs = New Image() {My.Resources.ChatUserGrn,My.Resources.ChatUserYlw,My.Resources.ChatUserRed,My.Resources.ChatBalloonGrn,My.Resources.ChatBalloonGry}
  76.  
  77.                ' see note
  78.         End If
  79.     End If
  80.         ' Add any initialization after the InitializeComponent() call.
  81.     End Sub
  82.     ' no need to create one without Identifiers
  83.     Public Sub New(n As Int32,cname As String)
  84.         MyClass.New()
  85.         ' default intitial values:
  86.         chName = cname
  87.         ChatId = n
  88.  
  89.         lblChName.Text = cname
  90.         Me.Status = ChatStatus.Online
  91.         Me.MsgStatus = ChatMsgStatus.Unknown
  92.     End Sub
  93. End Class

(编辑)我不喜欢使用ImageList的结果.此版本从资源加载一系列图像.除了只加载一个GreenUser副本供所有用户使用外,它还允许您根据需要进行定制.例如,将backcolor更改为SystemColors.Window以匹配用户的主题.如果您还使用标签而不是图片框,则可以使用Text属性“？”甚至指出新消息的数量.

我相信还有更多内容,我可以想到一些我希望它知道的事情(比如用未读消息的数量覆盖绿色气球).但这里的重点是封装,DRY和可重用代码的概念.

编译时,工具箱中会有一个新的Chatter控件.使用公开的属性在运行时添加一些：

  1. Dim c As New Chatter(42,"Ziggy von Hausen")
  2. flpChat.Controls.Add(c)
  3.  
  4. c = New Chatter(14,"ThDutoit")
  5. c.MsgStatus = Chatter.ChatMsgStatus.New
  6. flpChat.Controls.Add(c)
  7.  
  8. c = New Chatter(78,"Plutonix")
  9. c.Status = Chatter.ChatStatus.Offline
  10. flpChat.Controls.Add(c)
  11.  
  12. c = New Chatter(4,"Codexer")
  13. c.MsgStatus = Chatter.ChatMsgStatus.New
  14. c.Status = Chatter.ChatStatus.Away
  15. flpChat.Controls.Add(c)

Id将是唯一标识每个聊天参与者的东西.该名称通常不够(SO已超过50 pages of people named “Steve”),您将需要一种方法来识别将控件链接到用户. (另一种方法是,用户列表中的ChatterBox引用是对相关UserControl的引用：

  1. Dim user = "Codexer"
  2.  
  3. Dim chatter = flpChat.Controls.
  4.             OfType(Of Chatter).
  5.             FirstOrDefault(Function(c) c.ChatName.StartsWith(user))
  6. If chatter IsNot Nothing Then
  7.     chatter.Status = chatter.ChatStatus.Online
  8. End If

每次搜索都是次优的,并且Id会比仅仅名称更好.理想情况是ChatUser类包含应用程序必须由用户存储的所有其他内容.该类应包含对控件的引用,以便在状态发生变化时或类似情况下,类可以简单地：

  1. myChatterBox.Status = myStatus

结果：

当然,它们可以用相当少的代码创建.在这种情况下,您可以通过设置相关属性来更改任一图像的状态.

作为一个额外的好处,因为您不再创建单独的控件,并且因为UserControl继承自Component,所以如果/何时删除它们,您不必担心泄漏.

必读：
Creating a Windows Form User Control

猜你在找的VB相关文章

VB Format函数
Format[$] ( expr [ , fmt ] ) format 返回变体型 format$ 强制返回为文本 --------------...
vb6/ASP FORMAT MM/DD/YYYY
VB6或者ASP 格式化时间为 MM/dd/yyyy 格式，竟然没有好的办法， Format 或者FormatDateTi...
VB.net 捕获项目全局异常
在项目中添加如下代码：新建窗口来显示异常信息。 Namespace My ‘全局错误处理，新的...
实现用VB.Net/(C#)开发K/3 BOS 插件的真正可行方法
转了这一篇文章，原来一直想用C#做k3的插件开发，vb没有C#用的爽呀，这篇文章写与2011年，...
vb，wps，excel 分裂
Sub 分列() ‘以空格为分隔符，连续空格只算1个。对所选中的单元格进行处理 Dim m...
VB.NET MYSQL DataGridView 增删改查（INSERT,SELECT,UPDATE,DELETE）
  Imports MySql.Data.MySqlClient Public Class Form1 ‘ GLOBAL DECLARATIONS ...
VB.NET 使用ADODB連接資料庫滙出到EXCEL
‘導入命名空間 Imports ADODB Imports Microsoft.Office.Interop   Private Sub A1() Di...
vb.net 多线程運用 ping
Imports System.IO Imports System.Threading Imports System.Diagnostics Public Class F...
VB等待进程结束
VB运行EXE程序，并等待其运行结束 参考：https://blog.csdn.net/useway/article/details/5...
vb中去掉string数组的一部分
今天碰到一个问题，登陆的时候，如果不需要验证手机号为空，则不去验证手机号 因为登陆的时...
PHPJavaJava SEPythonC#C&C++RubyVBasp.NetGoPerlnettyDjangoDelphiJsp.NET CoreSpringFlaskSpringbootSpringMVCLuaLaravelMybatisAspGroovyThinkPHPYiiswoole
文件时间pythonm相等性PHP Warning时间问题问题解决pcntl_signal采样点wav模块动态文本调用频率限制对外暴露多个访问请求更新数据表模型结构type()方法比较速度手写体sobel算子保存模型Image类nn.Conv2dpytorch1.0kaggleDCGAN交并比range()用法打印模型反卷积卷积