4

CustomKeyboard/View/KBKeyButton.h

@@ -14,4 +14,7 @@
 /// 配置基础样式（背景、圆角等）。创建按钮时调用。
 - (void)applyDefaultStyle;
 
+/// 根据选中/高亮等状态刷新外观
+- (void)refreshStateAppearance;
+
 @end

CustomKeyboard/View/KBKeyButton.m

@@ -26,11 +26,31 @@
     self.layer.shadowOpacity = 1.0;
     self.layer.shadowOffset = CGSizeMake(0, 1);
     self.layer.shadowRadius = 1.5;
+    [self refreshStateAppearance];
 }
 
 - (void)setHighlighted:(BOOL)highlighted {
     [super setHighlighted:highlighted];
-    self.alpha = highlighted ? 0.7 : 1.0; // 简单按压反馈
+    // 简单按压反馈：选中态不改变透明度，避免和高亮态冲突
+    if (self.isSelected) {
+        self.alpha = 1.0;
+    } else {
+        self.alpha = highlighted ? 0.7 : 1.0;
+    }
+}
+
+- (void)setSelected:(BOOL)selected {
+    [super setSelected:selected];
+    [self refreshStateAppearance];
+}
+
+- (void)refreshStateAppearance {
+    // 选中态用于 Shift/CapsLock 等特殊按键的高亮显示
+    if (self.isSelected) {
+        self.backgroundColor = [UIColor colorWithWhite:0.85 alpha:1.0];
+    } else {
+        self.backgroundColor = [UIColor whiteColor];
+    }
 }
 
 @end

CustomKeyboard/View/KBKeyboardView.m

@@ -198,6 +198,11 @@
         [btn addTarget:self action:@selector(onKeyTapped:) forControlEvents:UIControlEventTouchUpInside];
         [row addSubview:btn];
 
+        // Shift 按钮选中态随大小写状态变化
+        if (key.type == KBKeyTypeShift) {
+            btn.selected = self.shiftOn;
+        }
+
         [btn mas_makeConstraints:^(MASConstraintMaker *make) {
             make.top.bottom.equalTo(row);
             if (previous) {