修复设置背景图解析bug；更新预览图

Author: DearVa

ExplorerEx/Settings.cs

@@ -289,8 +289,9 @@ public bool IsDarkMode {
 
 	public double BackgroundImageOpacity => this[CommonSettings.BackgroundImageOpacity].GetDouble();
 
-	private void BackgroundImage_OnChanged(object? o) {
-		if (o is string path && File.Exists(path)) {
+	private void BackgroundImage_OnChanged(SettingsItem si) {
+		var path = si.GetString().Trim(' ').Trim('"').Trim(' ');
+		if (File.Exists(path)) {
 			try {
 				BackgroundImage = new BitmapImage(new Uri(path));
 			} catch {
@@ -426,7 +427,7 @@ private void RegisterEvents() {
 		settings[CommonSettings.WindowBackdrop].Changed += _ => ThemeChanged?.Invoke();
 
 		settings[CommonSettings.BackgroundImage].Changed += BackgroundImage_OnChanged;
-		BackgroundImage_OnChanged(settings[CommonSettings.BackgroundImage].Value);
+		BackgroundImage_OnChanged(settings[CommonSettings.BackgroundImage]);
 
 		settings[CommonSettings.BackgroundImageOpacity].Changed += _ => OnPropertyChanged(nameof(BackgroundImageOpacity));
 		settings[CommonSettings.ColorMode].Changed += _ => ThemeChanged?.Invoke();  // 更改颜色

ExplorerEx/View/MainWindow.xaml.cs

@@ -817,9 +817,14 @@ protected override void OnRenderSizeChanged(SizeChangedInfo sizeInfo) {
 		}
 	}
 
+	/// <summary>
+	/// 是否打开了任何对话框？或者正在添加书签？
+	/// </summary>
+	private bool IsAnyDialogShown => RootPanel.Children.Count > 2 || IsAddToBookmarkShow;
+
 	protected override void OnKeyDown(KeyEventArgs e) {
 		var handled = true;
-		if (RootPanel.Children.Count == 2) {  // 没有打开任何对话框
+		if (!IsAnyDialogShown) {
 			var mouseOverTab = FileTabControl.MouseOverTabControl?.SelectedTab;
 			if (mouseOverTab != null) {
 				if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control) {
@@ -889,8 +894,7 @@ protected override void OnKeyDown(KeyEventArgs e) {
 	}
 
 	protected override void OnPreviewTextInput(TextCompositionEventArgs e) {
-		if ((RootPanel.Children.Count == 2 || !IsAddToBookmarkShow) &&
-			!string.IsNullOrWhiteSpace(e.Text) && e.OriginalSource is not TextBox and not AddressBar) {  // 没有打开任何对话框
+		if (!IsAnyDialogShown && !string.IsNullOrWhiteSpace(e.Text) && e.OriginalSource is not TextBox and not AddressBar) {
 			var mouseOverTabControl = FileTabControl.MouseOverTabControl;
 			if (mouseOverTabControl != null) {
 				var fileListView = mouseOverTabControl.SelectedTab.FileListView;