feat(HikVision): 增加抓图功能

Author: ArgoZhang

src/components/BootstrapBlazor.HikVision/Components/HikVisionWebPlugin.razor.cs

@@ -315,4 +315,44 @@ public async Task<bool> SetVolume(int value)
         }
         return ret;
     }
+
+    private TaskCompletionSource<IJSStreamReference?>? _captureTaskCompletionSource = null;
+
+    /// <summary>
+    /// 抓图方法返回 Url
+    /// </summary>
+    /// <returns></returns>
+    public async Task<IJSStreamReference?> CapturePicture(CancellationToken token = default)
+    {
+        IJSStreamReference? ret = null;
+        if (IsLogin && IsRealPlaying)
+        {
+            _captureTaskCompletionSource = new();
+
+            try
+            {
+                await InvokeVoidAsync("capturePicture", token, Id);
+                ret = await _captureTaskCompletionSource.Task;
+            }
+            catch (Exception ex)
+            {
+                _captureTaskCompletionSource.SetException(ex);
+            }
+        }
+        return ret;
+    }
+
+    /// <summary>
+    /// 抓图返回文件流方法 由 Javascript 调用
+    /// </summary>
+    /// <param name="stream"></param>
+    /// <returns></returns>
+    [JSInvokable]
+    public async Task TriggerReceivePictureStream(IJSStreamReference stream)
+    {
+        if (_captureTaskCompletionSource != null)
+        {
+            _captureTaskCompletionSource.SetResult(stream);
+        }
+    }
 }

src/components/BootstrapBlazor.HikVision/Components/HikVisionWebPlugin.razor.js

@@ -1,4 +1,4 @@
-import { init as initVision, login as loginVision, logout, startRealPlay, stopRealPlay, openSound, closeSound, setVolume, dispose as disposeVision } from '../hikvision.js';
+import { init as initVision, login as loginVision, logout, startRealPlay, stopRealPlay, openSound, closeSound, setVolume, capturePicture, capturePictureAndDownload, dispose as disposeVision } from '../hikvision.js';
 import Data from '../../BootstrapBlazor/modules/data.js';
 
 export async function init(id, invoke) {
@@ -29,7 +29,7 @@ export async function login(id, ip, port, userName, password, loginType) {
     return logined;
 }
 
-export { logout, startRealPlay, stopRealPlay, openSound, closeSound, setVolume }
+export { logout, startRealPlay, stopRealPlay, openSound, closeSound, setVolume, capturePicture, capturePictureAndDownload }
 
 export function dispose(id) {
     disposeVision(id);

src/components/BootstrapBlazor.HikVision/wwwroot/hikvision.js

@@ -409,6 +409,36 @@ export async function setVolume(id, value) {
     return code;
 }
 
+export async function capturePicture(id) {
+    const vision  = Data.get(id);
+    const { iWndIndex, realPlaying, invoke } = vision;
+
+    if (realPlaying !== true) {
+        return "";
+    }
+
+    try {
+        const base64 = await WebVideoCtrl.I_CapturePicData();
+        const bytes = base64ToArray(base64);
+        return DotNet.createJSStreamReference(bytes.buffer);
+    }
+    catch (ex) {
+        return null;
+    }
+}
+
+const base64ToArray = base64String => {
+    const base64Data = base64String.split(',')[1] || base64String;
+    const binaryString = atob(base64Data);
+    const length = binaryString.length;
+    const bytes = new Uint8Array(length);
+
+    for (let i = 0; i < length; i++) {
+        bytes[i] = binaryString.charCodeAt(i);
+    }
+
+    return bytes;
+}
 export function dispose(id) {
     const vision = Data.get(id);
     const { realPlaying, logined, observer } = vision;