winform遮罩层loading

[{"title":"（ 171 个子文件 503KB ） winform遮罩层loading","children":[{"title":"XControls.dll <span style='color:#111;'> 123.00KB </span>","children":null,"spread":false},{"title":"WindowsFormsApplication1.vshost.exe.manifest <span style='color:#111;'> 490B </span>","children":null,"spread":false},{"title":"WindowsFormsApplication1.vshost.exe <span style='color:#111;'> 11.33KB </span>","children":null,"spread":false},{"title":"WindowsFormsApplication1.exe <span style='color:#111;'> 17.00KB </span>","children":null,"spread":false},{"title":"Form1.Designer.cs <span style='color:#111;'> 3.32KB </span>","children":null,"spread":false},{"title":"......","children":null,"spread":false},{"title":"<span style='color:steelblue;'>文件过多，未全部展示</span>","children":null,"spread":false}],"spread":true}]