refactor(Modal): remove dialog variable (#5549)

* refactor: 更新脚本

* refactor: 删除冗余代码

* doc: 更新示例

* chore: bump version 9.4.7-beta04

Author: ArgoZhang

src/BootstrapBlazor.Server/Components/Samples/Modals.razor

@@ -237,7 +237,7 @@
            Name="IsDraggable">
     <Button OnClick="() => DragModal.Toggle()">@Localizer["ModalsNormalPopups"]</Button>
     <Modal @ref="DragModal">
-        <ModalDialog Title="@Localizer["ModalsNormalDefaultPopup"]" IsDraggable="true" ShowMaximizeButton="true">
+        <ModalDialog Title="@Localizer["ModalsNormalDefaultPopup"]" IsDraggable="true">
             <BodyTemplate>
                 <div>@Localizer["ModalsTitlePopupWindowText"]</div>
             </BodyTemplate>

src/BootstrapBlazor/BootstrapBlazor.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Razor">
 
   <PropertyGroup>
-    <Version>9.4.7-beta03</Version>
+    <Version>9.4.7-beta04</Version>
   </PropertyGroup>
 
   <ItemGroup>

src/BootstrapBlazor/Components/Modal/Modal.razor.js

@@ -22,13 +22,6 @@ export function init(id, invoke, shownCallback, closeCallback) {
     })
     EventHandler.on(el, 'hidden.bs.modal', e => {
         e.stopPropagation();
-        if (modal.draggable) {
-            modal.dialog.style.width = ''
-            modal.dialog.style.margin = ''
-
-            EventHandler.off(modal.dialog, 'mousedown')
-            EventHandler.off(modal.dialog, 'touchstart')
-        }
         invoke.invokeMethodAsync(closeCallback)
     })
     EventHandler.on(window, 'popstate', modal.pop)
@@ -154,13 +147,13 @@ export function dispose(id) {
 }
 
 const backupBodyStyle = modal => {
-    if(modal.originalStyle === void 0) {
+    if (modal.originalStyle === null) {
         modal.originalStyle = document.body.style.cssText;
     }
 }
 
 const restoreBodyStyle = modal => {
-    if(modal.originalStyle !== void 0) {
+    if (modal.originalStyle !== null) {
         document.body.style.cssText = modal.originalStyle;
         delete modal.originalStyle;
     }