fix: copy cmd notify delay problem

STranslate/MainWindow.xaml

@@ -22,6 +22,9 @@
     <Window.DataContext>
         <vm:MainVM />
     </Window.DataContext>
+    <Window.Resources>
+        <hc:String2VisibilityConverter x:Key="String2VisibilityConverter"/>
+    </Window.Resources>
     <Border BorderThickness="0"
             Background="#fff"
             CornerRadius="10">
@@ -107,6 +110,7 @@
                                 Margin="5,0,0,5"
                                 HorizontalAlignment="Left"
                                 VerticalAlignment="Bottom"
+                                    Visibility="{Binding InputTxt,Converter={StaticResource String2VisibilityConverter}}"
                                 Command="{Binding CopyInputCmd}">
                             <Image Source="/Images/copy2.png"/>
                         </Button>
@@ -182,6 +186,7 @@
                                     HorizontalAlignment="Left"
                                     VerticalAlignment="Bottom"
                                     ToolTip="直接复制"
+                                    Visibility="{Binding OutputTxt,Converter={StaticResource String2VisibilityConverter}}"
                                     Command="{Binding CopyResultCmd}">
                                 <Image Source="/Images/copy2.png"/>
                             </Button>
@@ -191,6 +196,7 @@
                                     HorizontalAlignment="Left"
                                     VerticalAlignment="Bottom"
                                     ToolTip="蛇形"
+                                    Visibility="{Binding SnakeRet,Converter={StaticResource String2VisibilityConverter}}"
                                     Command="{Binding CopySnakeResultCmd}">
                                 <Image Source="/Images/copy_s.png"/>
                             </Button>
@@ -199,6 +205,7 @@
                                     HorizontalAlignment="Left"
                                     VerticalAlignment="Bottom"
                                     ToolTip="小驼峰"
+                                    Visibility="{Binding SmallHumpRet,Converter={StaticResource String2VisibilityConverter}}"
                                     Command="{Binding CopySmallHumpResultCmd}">
                                 <Image Source="/Images/copy_h.png"/>
                             </Button>
@@ -207,6 +214,7 @@
                                     HorizontalAlignment="Left"
                                     VerticalAlignment="Bottom"
                                     ToolTip="大驼峰"
+                                    Visibility="{Binding LargeHumpRet,Converter={StaticResource String2VisibilityConverter}}"
                                     Command="{Binding CopyLargeHumpResultCmd}">
                                 <Image Source="/Images/copy_h2.png"/>
                             </Button>

STranslate/ViewModel/MainVM.cs

@@ -37,42 +37,27 @@ namespace STranslate.ViewModel
             config = ConfigUtil.ReadConfig(ConfigPath);
 
             //复制输入
-            CopyInputCmd = new RelayCommand((_) =>
+            CopyInputCmd = new RelayCommand((_) => true, (_) =>
-            {
-                return string.IsNullOrEmpty(InputTxt) ? false : true;
-            }, (_) =>
             {
                 Clipboard.SetText(InputTxt);
             });
             //复制翻译结果
-            CopyResultCmd = new RelayCommand((_) =>
+            CopyResultCmd = new RelayCommand((_) => true, (_) =>
-            {
-                return string.IsNullOrEmpty(OutputTxt) ? false : true;
-            }, (_) =>
             {
                 Clipboard.SetText(OutputTxt);
             });
             //复制蛇形结果
-            CopySnakeResultCmd = new RelayCommand((_) =>
+            CopySnakeResultCmd = new RelayCommand((_) => true, (_) =>
-            {
-                return string.IsNullOrEmpty(SnakeRet) ? false : true;
-            }, (_) =>
             {
                 Clipboard.SetText(SnakeRet);
             });
             //复制小驼峰结果
-            CopySmallHumpResultCmd = new RelayCommand((_) =>
+            CopySmallHumpResultCmd = new RelayCommand((_) => true, (_) =>
-            {
-                return string.IsNullOrEmpty(SmallHumpRet) ? false : true;
-            }, (_) =>
             {
                 Clipboard.SetText(SmallHumpRet);
             });
             //复制大驼峰结果
-            CopyLargeHumpResultCmd = new RelayCommand((_) =>
+            CopyLargeHumpResultCmd = new RelayCommand((_) => true, (_) =>
-            {
-                return string.IsNullOrEmpty(LargeHumpRet) ? false : true;
-            }, (_) =>
             {
                 Clipboard.SetText(LargeHumpRet);
             });