你是对的。但这里是使标签的背景色透明的最简单方法。在该标签的属性窗口中选择Web。。在Web中选择透明：）

this.label1.BackColor = System.Drawing.Color.Transparent;

让我们看看两种可能的情况。
1.背景是一种颜色，在VS构造函数中双击窗体背景，然后编写如下代码：

/*
This code will set all your object's background color to the same as the form.
This should be written in the body of <FormName>_Load(object, EventArgs).
*/
Control[] objs = new Control[] { /* your object list, e. g { myLabel, myPicture } */ };
foreach (Control control in objs) {
  control.BackColor = Color.Transparent;
  // OR
  control.BackColor = this.BackColor;
}

1. Background是一个PictureBox。这也很简单。我们只需要将所有对象作为PictureBox的子对象，并将其颜色设置为透明。代码：

/*
This code will set all your object's background to transparent and show the PBox.
This should be written in the body of <FormName>_Load(object, EventArgs)'s foreach loop.
Put everything before it the same as in 1st code fragment.
*/
control.Parent = back;
control.BackColor = Color.Transparent;

让我们看看照片。

• 颜色
• Before
• After
• PictureBox
• Before
• After（这里的前景被改变了，不要介意这个）

通常，出现在图像前面的标签和文本框最好在面板中组织。渲染时，如果标签需要对面板中的图像透明，您可以在表单初始化中切换到图像作为标签的父级，如下所示：

var oldParent = panel1;
var newParent = pictureBox1;

foreach (var label in oldParent.Controls.OfType<Label>())
{
    label.Location = newParent.PointToClient(label.Parent.PointToScreen(label.Location));
    label.Parent = newParent;
    label.BackColor = Color.Transparent;
}

它使用Graphics.CopyFromScreen，因此当控件在屏幕上可见时需要添加它。

public partial class TransparentLabelControl : Label
{
    public TransparentLabelControl()
    {
        this.AutoSize = true;
        this.Visible = false;

        this.ImageAlign = ContentAlignment.TopLeft;
        this.Visible = true;

        this.Resize += TransparentLabelControl_Resize;
        this.LocationChanged += TransparentLabelControl_LocationChanged;
        this.TextChanged += TransparentLabelControl_TextChanged;
        this.ParentChanged += TransparentLabelControl_ParentChanged;
    }

    #region Events
    private void TransparentLabelControl_ParentChanged(object sender, EventArgs e)
    {
        SetTransparent();
        if (this.Parent != null)
        {
            this.Parent.ControlAdded += Parent_ControlAdded;
            this.Parent.ControlRemoved += Parent_ControlRemoved;
        }
    }

    private void Parent_ControlRemoved(object sender, ControlEventArgs e)
    {
        SetTransparent();
    }

    private void Parent_ControlAdded(object sender, ControlEventArgs e)
    {
        if (this.Bounds.IntersectsWith(e.Control.Bounds))
        {
            SetTransparent();
        }
    }

    private void TransparentLabelControl_TextChanged(object sender, EventArgs e)
    {
        SetTransparent();
    }

    private void TransparentLabelControl_LocationChanged(object sender, EventArgs e)
    {

        SetTransparent();
    }

    private void TransparentLabelControl_Resize(object sender, EventArgs e)
    {
        SetTransparent();
    }
    #endregion

    public void SetTransparent()
    {
        if (this.Parent!= null)
        {
            this.Visible = false;
            this.Image = this.takeComponentScreenShot(this.Parent);
            this.Visible = true;                
        }
    }

    private  Bitmap takeComponentScreenShot(Control control)
    {
        Rectangle rect = control.RectangleToScreen(this.Bounds);
        if (rect.Width == 0 || rect.Height == 0)
        {
            return null;
        }
        Bitmap bmp = new Bitmap(rect.Width, rect.Height, PixelFormat.Format32bppArgb);
        Graphics g = Graphics.FromImage(bmp);

        g.CopyFromScreen(rect.Left, rect.Top, 0, 0, bmp.Size, CopyPixelOperation.SourceCopy);

        return bmp;
    }

}

要使标签后面带有图片，一个简单的方法是使用标签本身的Image属性。这将在图片的顶部打印文本，并允许您根据需要对齐图像（上/下/左/右/中心）。picture

另一种选择可能是：

label1.BackColor = Color.Empty;

是否要使标签（除文本外）透明？Windows窗体（我假设是WinForms -这是真的吗）并不真正支持透明。最简单的方法有时是将标签的Backcolor设置为Transparent。

label1.BackColor = System.Drawing.Color.Transparent;

但是你会遇到一些问题，因为WinForms确实不支持透明性。否则，请看这里：
http://www.doogal.co.uk/transparent.php
http://www.codeproject.com/KB/dotnet/transparent_controls_net.aspx
http://www.daniweb.com/code/snippet216425.html
设置usercontrol的父级会阻止它透明
祝你好运！

如果你在背景中的图片框，然后使用这个：

label1.Parent = pictureBox1;
label1.BackColor = Color.Transparent;

将此代码放在InitializeComponent();下面或Form_Load方法中。
参考：https://www.c-sharpcorner.com/blogs/how-to-make-a-transparent-label-over-a-picturebox1