设置 ComboBox 的每个项目的 BackColor 属性

Question

这是我目前在下面的代码，其中填充了数组([System.Drawing.Color] | Get-Member -Static -MemberType Properties).name。

我试图查看是否有任何方法可以将每个项目的 BackColor 属性设置为与颜色的相同数组元素匹配，但没有。

理想情况下，我希望在名称左侧添加一点颜色样本。

编辑： 从那以后，我发现您可以为控件添加一个事件处理程序，但我仍然不确定如何更改每个项目以显示一个小样本。我已经更新了下面的代码，因为其他代码不是那么接近。

我目前的代码：

Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()

$Form                 = New-Object system.Windows.Forms.Form
$Form.Font            = [System.Drawing.Font]::New("Segoe UI", 10, [System.Drawing.FontStyle]::Regular) # Bold, Italic, Regular, Strikeout or Underline
$Form.StartPosition   = 'CenterScreen'
$Form.Text            = 'How do I Change Each Items Colour to Match Their Name?'
$Form.Width           = 500
$Form.Height          = 69
$Form.FormBorderStyle = [System.Windows.Forms.FormBorderStyle]::FixedSingle # 1 A fixed, single-line border
$Form.SizeGripStyle   = [System.Windows.Forms.SizeGripStyle]::Hide # 2 The sizing grip is hidden.

$combo                    = New-Object System.Windows.Forms.ComboBox
$combo.DrawMode           = 'OwnerDrawFixed'
$combo.FlatStyle          = [System.Windows.Forms.FlatStyle]::System
$combo.Font               = [System.Drawing.Font]::New("Segoe UI", 14, [System.Drawing.FontStyle]::Regular) # Bold, Italic, Regular, Strikeout or Underline
$combo.Width              = $Form.Width-1-$combo.Height+($combo.Margin.Left+$combo.Margin.Right)
$combo.AutoCompleteMode   = 'SuggestAppend' # Enables searching but not mid string. Need to find a solution for this.
$combo.AutoCompleteSource = 'ListItems'
$combo.AutoSize           = $true
$combo.DropDownStyle      = 'DropDownList'
$combo.ItemHeight         = 24

$colorNamesArr = ([System.Drawing.Color] | Get-Member -Static -MemberType Properties).name # Here's the array of colour that are to get added to the ComboBox.
$combo.Items.AddRange($colorNamesArr) # Add the array to the ComboBox.
$Form.Controls.Add($combo)

# HERE'S WHERE I NEED HELP.

# How do I change the colours of the ComboBox items to match that of their name.

$combo.Add_DrawItem({param($sender,$e)
    $text = "-- Select Color --"
    if ($e.Index -gt -1){
        $text = $sender.GetItemText($sender.Items[$e.Index])
    }
    $e.DrawBackground()

    [System.Windows.Forms.TextRenderer]::DrawText($e.Graphics, $text, $combo.Font, $e.Bounds, $e.ForeColor, [System.Windows.Forms.TextFormatFlags]::Default)

})
$Form.ShowDialog() | Out-Null
$Form.Dispose()

Answer 1

您需要覆盖绘制 ComboBox 的事件。如果您想在每个名称旁边添加颜色，下面是一个示例，说明您可以如何做到这一点。

Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()

$Form               = New-Object system.Windows.Forms.Form
$Form.StartPosition = 'CenterScreen'
$Form.Text          = "How do I Change Each Items Colour to Match Their Name?"
$Form.Width         = 500
$Form.Height        = 72

$cbSearch               = New-Object system.Windows.Forms.ComboBox
$cbSearch.Font          = [System.Drawing.Font]::New("Segoe UI", 14, [System.Drawing.FontStyle]::Regular) # Bold, Italic, Regular, Strikeout or Underline
$cbSearch.Width         = $Form.Width-1-$cbSearch.Height+($cbSearch.Margin.Left+$cbSearch.Margin.Right)
$cbSearch.DropDownStyle = 'DropDownList'

# Setting up the ComboBox.
$colorNamesArr = ([System.Drawing.Color] | Get-Member -Static -MemberType Properties).name
#Add the array to the ComboBox.
$colorNamesArr | ForEach-Object {[void] $cbSearch.Items.Add($_)}
#Set the first item when opened.
$cbSearch.Text = $colorNamesArr[0]

## Allow override of graphical rendering of the Combobox.
$cbSearch.DrawMode = [System.Windows.Forms.DrawMode]::OwnerDrawFixed

## Add an event that draws each item.
$cbSearch.add_DrawItem({
    param([object]$s, [System.Windows.Forms.DrawItemEventArgs]$e)

    $Graphics = $e.Graphics
    $Rectangle = $e.Bounds
    # Clear the previous drawing
    $e.DrawBackground()
    if ($e.Index -ge 0) {
        $Name = ([System.Windows.Forms.ComboBox]$s).Items[$e.Index].ToString()
        $Font = [System.Drawing.Font]::new("Arial", 10, [System.Drawing.FontStyle]::Regular)
        $Color = [System.Drawing.Color]::FromName($Name)
        $Brush = [System.Drawing.SolidBrush]::new($Color)
        # Can uncomment this if you do not want the background highlighted when hovering over item.
        # $Graphics.TextRenderingHint = [System.Drawing.Text.TextRenderingHint]::AntiAliasGridFit
        $Graphics.DrawString($Name, $Font, [System.Drawing.Brushes]::Black, $Rectangle.X, $Rectangle.Top)
        $Graphics.FillRectangle($Brush, $Rectangle.X + 110, $Rectangle.Y + 5, $Rectangle.Width -10, $Rectangle.Height -10)

        # Dispose of disposable objects
        $Brush.Dispose()
    }
})

# Add any controls to the form.
$Form.Controls.Add($cbSearch)

# This below needs to be added to focus the dialog when it opens after the ColorDialog.
$Form.Add_Shown({$Form.Activate(); $cbSearch.Focus()})

[void]$Form.ShowDialog()

调整设置以将绘图更改为您的偏好。

从this code改编为PowerShell。

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编辑

如果您想更改彩色框的位置和大小，请参阅此示例。

$Graphics.DrawString($Name, $Font, [System.Drawing.Brushes]::Black, $Rectangle.X + 40, $Rectangle.Top + 5)
$Graphics.FillRectangle($Brush, $Rectangle.X + 10, $Rectangle.Y + 2, $Rectangle.Width - 440, $Rectangle.Height - 4)

X 和 Y 覆盖对象框内的定位。高度和宽度是盒子本身的大小。