WinForm 基于.NET6使用PNG图片实现透明背景启动页面（文末附加.NET Framework 4.8相关操作）

参考

• 豆包
• https://www.codeleading.com/article/83363029133/
• https://www.delftstack.com/zh/howto/csharp/csharp-repeat-string-x-times/#google_vignette
• https://www.cnblogs.com/liquan/p/8859206.html
• https://bbs.csdn.net/topics/90398756
• https://learn.microsoft.com/zh-cn/dotnet/core/compatibility/core-libraries/5.0/thread-abort-obsolete
• https://www.cnblogs.com/yuxuetaoxp/p/3873074.html
• https://blog.csdn.net/qq_27508477/article/details/87716638
• https://www.cnblogs.com/gzskys/p/5661302.html
• https://www.cnblogs.com/log9527blog/p/17616377.html
• https://blog.csdn.net/kucoffee12/article/details/83538104
• https://wenku.csdn.net/answer/82z74jbqnk
• https://blog.csdn.net/weixin_40333655/article/details/101448061
• https://blog.csdn.net/qq_36240878/article/details/84024369
• https://zhuanlan.zhihu.com/p/203689190
• https://blog.csdn.net/weixin_45023644/article/details/122893571
• https://blog.csdn.net/weixin_44429033/article/details/123645544
• https://bbs.csdn.net/topics/330035058
• https://blog.csdn.net/BADAO_LIUMANG_QIZHI/article/details/100110550

环境

软件/系统	版本	说明
Windows	windows 10 专业版 22H2 64 位操作系统, 基于 x64 的处理器
Microsoft Visual Studio	Community 2022 (64 位) - Current 版本 17.13.6
.NET SDK	6.0

预览

相关知识点

1. 启动页需要以ShowDialog形式启动。
2. UI更新需要在所在线程更新，或者通过 BeginInvoke或Invoke操作 ，否则报错System.InvalidOperationException:“线程间操作无效: 从不是创建控件“progressBar1”的线程访问它。”
3. BeginInvoke、Invoke区别在于执行方式的同步性和异步性。
4. 窗体设置前景色TransparencyKey透明才可以实现透明效果。
5. WinFrom 支持多种方式引入资源文件，测试 .net6 出现 Resources.resx 导入图片后，图片的类型变成了 Bitmap，需要以Image.FromHbitmap(Properties.Resources._1747273852844.GetHbitmap())形式进行读取，才能给 PictureBox 设置图片，但是会变成非透明图片，可能需要重新绘制。

源码

布局需要给 StartPage.cs 拖拽 Label、ProgressBar、PictureBox 三个控件，然后隐藏窗体工具栏。

1. Program.cs

   namespace WinFormsApp4
   {
   	internal static class Program
   	{
   		/// <summary>
   		///  The main entry point for the application.
   		/// </summary>
   		[STAThread]
   		static void Main()
   		{
   			// To customize application configuration such as set high DPI settings or default font,
   			// see https://aka.ms/applicationconfiguration.
   			ApplicationConfiguration.Initialize();
   			StartPage startPage = new StartPage();
   			startPage.ShowDialog();
   			Application.Run(new Form1());
   		}
   	}
   }
   

2. StartPage.cs

   using System;
   using System.Collections.Generic;
   using System.ComponentModel;
   using System.Data;
   using System.Drawing;
   using System.Linq;
   using System.Text;
   using System.Threading.Tasks;
   using System.Windows.Forms;
   using static System.Windows.Forms.VisualStyles.VisualStyleElement.TrayNotify;
   
   namespace WinFormsApp4
   {
   	public partial class StartPage : Form
   	{
   		private Thread thread;
   		public StartPage()
   		{
   			InitializeComponent();
   			// 透明
   			this.TransparencyKey = this.BackColor;
   			// 居中
   			this.StartPosition = FormStartPosition.CenterScreen;
   			// 通过界面上操作给pictureBox1添加图片是透明图片，通过这种方式可能不是透明图片
   			// this.pictureBox1.Image = Image.FromHbitmap(Properties.Resources._1747273852844.GetHbitmap());
   			// 加载动画
   			thread = new Thread(LoadCallBack);
   			thread.IsBackground = true;
   			thread.Start();
   		}
   
   		private void LoadCallBack()
   		{
   			for (int i = 0; i < 100; i++)
   			{
   				Thread.Sleep(60);
   				// 在创建控件的基础句柄所在线程上异步执行指定委托。
   				this.BeginInvoke(() =>
   				{
   					this.progressBar1.Value = i;
   					this.label1.Text = "程序启动中" + String.Concat(Enumerable.Repeat(".", i % 6));
   				});
   			}
   			this.BeginInvoke(() =>
   			{
   				this.Close();
   			});
   		}
   	}
   }
   
   

3. Form1.cs

   	namespace WinFormsApp4
   	{
   		public partial class Form1 : Form
   		{
   			public Form1()
   			{
   				InitializeComponent();
   				// 居中
   				this.StartPosition = FormStartPosition.CenterScreen;
   			}
   		}
   	}
   

.NET Framework 4.8 实现更新进度条

1. 线程方式

   // 线程方式
   private void Starting_Load(object sender, EventArgs e)
   {
   	Thread thread = new Thread(UpdateProgress);
   	thread.IsBackground = true;
   	thread.Start();
   }
   private void UpdateProgress()
   {
   	for (int i = 0; i < 100; i++)
   	{
   		Thread.Sleep(20);
   		this.BeginInvoke(new Action(() =>
   									{
   										this.progressBar1.Value = i;
   										this.label1.Text = "程序启动中" + String.Concat(Enumerable.Repeat(".", i % 6));
   
   									}));
   	}
   	this.BeginInvoke(new Action(() =>
   								{
   									this.Close();
   								}));
   
   }
   // 线程方式end
   

2. 计时器方式

   // 计时器方式
   private void Starting_Load(object sender, EventArgs e)
   {
   	this.timer1.Start();
   }
   
   private int currentProgress = 0;
   private void timer1_Tick(object sender, EventArgs e)
   {
   	++currentProgress;
   	this.progressBar1.Value = currentProgress;
   	this.label1.Text = "程序启动中" + String.Concat(Enumerable.Repeat(".", currentProgress % 6));
   	if (currentProgress >= 100)
   	{
   		this.timer1.Stop();
   		this.Close();
   	}
   }
   // 计时器方式end