1，LoaderForm窗体中添加PictureBox，然后添加Loading图片
2，窗体内属性设置
StartPosition :CenterScreen在屏幕中心显示
TopMost:True置顶显示
ShowInTaskbar:False不在任务栏显示
FormBorderStyle:None不显示窗体边框和标题栏
TransparencyKey:Control颜色为Control的部分透明
BackColor:Control窗体背景颜色设为Control
3，调用：
LoadingHelper.ShowLoadingScreen();//显示
LoadingHelper.CloseForm();//关闭
4，显示效果如下：
5，LoaderForm和LoadingHelper部分代码如下，ref:https://www.cnblogs.com/morewindows0/p/7107599.html
LoaderForm:
public partial class LoaderForm : Form { public LoaderForm() { InitializeComponent(); } /// <summary> /// 关闭命令 /// </summary> public void closeOrder() { if (this.InvokeRequired) { //这里利用委托进行窗体的操作，避免跨线程调用时抛异常，后面给出具体定义 CONSTANTDEFINE.SetUISomeInfo UIinfo = new CONSTANTDEFINE.SetUISomeInfo(new Action(() => { while (!this.IsHandleCreated) { ; } if (this.IsDisposed) return; if (!this.IsDisposed) { this.Dispose(); } })); this.Invoke(UIinfo); } else { if (this.IsDisposed) return; if (!this.IsDisposed) { this.Dispose(); } } } private void LoaderForm_FormClosing(object sender, FormClosingEventArgs e) { if (!this.IsDisposed) { this.Dispose(true); } } } class CONSTANTDEFINE { public delegate void SetUISomeInfo(); }
LoadingHelper:
public class LoadingHelper { #region 相关变量定义 /// <summary> /// 定义委托进行窗口关闭 /// </summary> private delegate void CloseDelegate(); private static LoaderForm loadingForm; private static readonly Object syncLock = new Object(); //加锁使用 #endregion //private LoadingHelper() //{ //} /// <summary> /// 显示loading框 /// </summary> public static void ShowLoadingScreen() { // Make sure it is only launched once. if (loadingForm != null) return; Thread thread = new Thread(new ThreadStart(LoadingHelper.ShowForm)); thread.IsBackground = true; thread.SetApartmentState(ApartmentState.STA); thread.Start(); } /// <summary> /// 显示窗口 /// </summary> private static void ShowForm() { if (loadingForm != null) { loadingForm.closeOrder(); loadingForm = null; } loadingForm = new LoaderForm(); loadingForm.TopMost = true; loadingForm.ShowDialog(); } /// <summary> /// 关闭窗口 /// </summary> public static void CloseForm() { Thread.Sleep(50); //可能到这里线程还未起来，所以进行延时，可以确保线程起来，彻底关闭窗口 if (loadingForm != null) { lock (syncLock) { Thread.Sleep(50); if (loadingForm != null) { Thread.Sleep(50); //通过三次延时，确保可以彻底关闭窗口 loadingForm.Invoke(new CloseDelegate(LoadingHelper.CloseFormInternal)); } } } } /// <summary> /// 关闭窗口，委托中使用 /// </summary> private static void CloseFormInternal() { loadingForm.closeOrder(); loadingForm = null; } }