doc: 增加打开设备逻辑

Author: ArgoZhang

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

@@ -14,9 +14,9 @@ private IBluetooth? BluetoothService { get; set; }</Pre>
     <div class="row form-inline g-3">
         <div class="col-12">
             <Button Text="@Localizer["VideoDeviceRequestText"]" Icon="fa-solid fa-photo-film" OnClick="OnRequestDevice"></Button>
-            <Button Text="@Localizer["VideoDeviceOpenText"]" Icon="fa-solid fa-play" OnClick="OnOpenVideo" class="ms-2"></Button>
-            <Button Text="@Localizer["VideoDeviceCloseText"]" Icon="fa-solid fa-stop" OnClick="OnCloseVideo" class="ms-2"></Button>
-            <Button Text="@Localizer["VideoDeviceCaptureText"]" Icon="fa-solid fa-camera" OnClick="OnCapture" class="ms-2"></Button>
+            <Button Text="@Localizer["VideoDeviceOpenText"]" Icon="fa-solid fa-play" OnClick="OnOpenVideo" IsDisabled="_isOpen" class="ms-2"></Button>
+            <Button Text="@Localizer["VideoDeviceCloseText"]" Icon="fa-solid fa-stop" OnClick="OnCloseVideo" IsDisabled="!_isOpen" class="ms-2"></Button>
+            <Button Text="@Localizer["VideoDeviceCaptureText"]" Icon="fa-solid fa-camera" OnClick="OnCapture" IsDisabled="!_isOpen" class="ms-2"></Button>
         </div>
         <div class="col-12">
             <Select Items="@_items" @bind-Value="_deviceId" DisplayText="Devices" ShowLabel="true"></Select>

src/BootstrapBlazor.Server/Components/Samples/VideoDevices.razor.cs

@@ -21,6 +21,8 @@ public partial class VideoDevices
 
     private string? _previewUrl;
 
+    private bool _isOpen = false;
+
     private async Task OnRequestDevice()
     {
         var devices = await VideoDeviceService.GetDevices();
@@ -41,7 +43,7 @@ private async Task OnOpenVideo()
                 DeviceId = _deviceId,
                 VideoSelector = ".bb-video"
             };
-            await VideoDeviceService.Open(constraints);
+            _isOpen =  await VideoDeviceService.Open(constraints);
         }
     }