feat(PdfReader): add OnScaleChangedAsync parameter (#756)

* feat(PdfReader): add localization support

* chore: bump version 10.0.8

* feat: 支持页面适配模式外部更改

* feat: add OnScaleChangedAsync parameter

Author: ArgoZhang

src/components/BootstrapBlazor.PdfReader/PdfReader.razor.cs

@@ -103,6 +103,12 @@ public partial class PdfReader
     [Parameter]
     public Func<bool, Task>? OnTwoPagesOneViewAsync { get; set; }
 
+    /// <summary>
+    /// 设置缩放倍率回调方法
+    /// </summary>
+    [Parameter]
+    public Func<float, Task>? OnScaleChangedAsync { get; set; }
+
     /// <summary>
     /// 获得/设置 更多按钮图标 默认为 null 使用内置图标
     /// </summary>
@@ -225,7 +231,8 @@ protected override async Task OnAfterRenderAsync(bool firstRender)
         TriggerPagesInit = OnPagesInitAsync != null,
         TriggerPagesLoaded = OnPagesLoadedAsync != null,
         TriggerPageChanged = OnPageChangedAsync != null,
-        TriggerTowPagesOnViewChanged = OnTwoPagesOneViewAsync != null
+        TriggerTowPagesOnViewChanged = OnTwoPagesOneViewAsync != null,
+        TriggerScaleChanged = OnScaleChangedAsync != null
     });
 
     /// <summary>
@@ -302,6 +309,19 @@ public async Task PageChanged(uint pageIndex)
         }
     }
 
+    /// <summary>
+    /// 缩放倍率更改回调方法
+    /// </summary>
+    /// <returns></returns>
+    [JSInvokable]
+    public async Task ScaleChanged(float val)
+    {
+        if (OnScaleChangedAsync != null)
+        {
+            await OnScaleChangedAsync(val);
+        }
+    }
+
     /// <summary>
     /// 正在打印回调方法
     /// </summary>

src/components/BootstrapBlazor.PdfReader/PdfReader.razor.js

@@ -349,7 +349,13 @@ const addEventBus = (el, pdfViewer, eventBus, invoke, options) => {
     }, true);
 
 
-    eventBus.on("scalechanging", evt => updateScaleValue(el, evt.scale));
+    eventBus.on("scalechanging", async evt => {
+        updateScaleValue(el, evt.scale);
+
+        if (options.triggerScaleChanged) {
+            await invoke.invokeMethodAsync("ScaleChanged", evt.scale);
+        }
+    })
 
     eventBus.on("rotationchanging", evt => {
         const thumbnailsContainer = el.querySelector(".bb-view-thumbnails");