diff --git a/CustomKeyboard/KeyboardViewController.m b/CustomKeyboard/KeyboardViewController.m
index e8f08f1..12c1e30 100644
--- a/CustomKeyboard/KeyboardViewController.m
+++ b/CustomKeyboard/KeyboardViewController.m
@@ -14,7 +14,7 @@
 
 static CGFloat KEYBOARDHEIGHT = 256;
 
-@interface KeyboardViewController () <KBKeyBoardMainViewDelegate>
+@interface KeyboardViewController () <KBKeyBoardMainViewDelegate, KBFunctionViewDelegate>
 @property (nonatomic, strong) UIButton *nextKeyboardButton; // 系统“下一个键盘”按钮（可选）
 @property (nonatomic, strong) KBKeyBoardMainView *keyBoardMainView;   // 功能面板视图（点击工具栏第0个时显示）
 @property (nonatomic, strong) KBFunctionView *functionView;   // 功能面板视图（点击工具栏第0个时显示）
@@ -22,11 +22,6 @@ static CGFloat KEYBOARDHEIGHT = 256;
 
 @implementation KeyboardViewController
 
-- (void)updateViewConstraints {
-    [super updateViewConstraints];
-    
-    // 可在此添加自定义尺寸约束
-}
 
 - (void)viewDidLoad {
     [super viewDidLoad];
@@ -46,7 +41,6 @@ static CGFloat KEYBOARDHEIGHT = 256;
         make.bottom.equalTo(self.view.mas_bottom).offset(-4);
     }];
     
-    self.keyBoardMainView.delegate = self;
     [self.view addSubview:self.keyBoardMainView];
     [self.keyBoardMainView mas_makeConstraints:^(MASConstraintMaker *make) {
         make.left.right.equalTo(self.view);
@@ -64,7 +58,7 @@ static CGFloat KEYBOARDHEIGHT = 256;
     // 简单显隐切换，复用相同的布局区域
     self.functionView.hidden = !show;
     self.keyBoardMainView.hidden = show;
-
+    
     // 可选：把当前显示的视图置顶，避免层级遮挡
     if (show) {
         [self.view bringSubviewToFront:self.functionView];
@@ -76,7 +70,6 @@ static CGFloat KEYBOARDHEIGHT = 256;
 
 
 // MARK: - KBKeyBoardMainViewDelegate
-
 - (void)keyBoardMainView:(KBKeyBoardMainView *)keyBoardMainView didTapKey:(KBKey *)key {
     switch (key.type) {
         case KBKeyTypeCharacter:
@@ -99,7 +92,6 @@ static CGFloat KEYBOARDHEIGHT = 256;
 }
 
 - (void)keyBoardMainView:(KBKeyBoardMainView *)keyBoardMainView didTapToolActionAtIndex:(NSInteger)index {
-    // 符合你的要求：由控制器来切换面板
     if (index == 0) {
         [self showFunctionPanel:YES];
     } else {
@@ -107,10 +99,19 @@ static CGFloat KEYBOARDHEIGHT = 256;
     }
 }
 
+// MARK: - KBFunctionViewDelegate
+- (void)functionView:(KBFunctionView *)functionView didTapToolActionAtIndex:(NSInteger)index {
+    // 需求：当 index == 0 时，切回键盘主视图
+    if (index == 0) {
+        [self showFunctionPanel:NO];
+    }
+}
+
 #pragma mark - lazy
 - (KBKeyBoardMainView *)keyBoardMainView{
     if (!_keyBoardMainView) {
         _keyBoardMainView = [[KBKeyBoardMainView alloc] init];
+        _keyBoardMainView.delegate = self;
     }
     return _keyBoardMainView;
 }
@@ -118,10 +119,12 @@ static CGFloat KEYBOARDHEIGHT = 256;
 - (KBFunctionView *)functionView{
     if (!_functionView) {
         _functionView = [[KBFunctionView alloc] init];
+        _functionView.delegate = self; // 监听功能面板顶部Bar点击
     }
     return _functionView;
 }
 
+
+
+
 @end
-
-
diff --git a/CustomKeyboard/View/KBFunctionBarView.h b/CustomKeyboard/View/KBFunctionBarView.h
index ef6e1a8..e422613 100644
--- a/CustomKeyboard/View/KBFunctionBarView.h
+++ b/CustomKeyboard/View/KBFunctionBarView.h
@@ -10,8 +10,20 @@
 NS_ASSUME_NONNULL_BEGIN
 
 /// 功能区顶部的Bar：左侧4个按钮，右侧3个按钮
+@class KBFunctionBarView;
+
+@protocol KBFunctionBarViewDelegate <NSObject>
+@optional
+/// 左侧 4 个按钮点击（index: 0~3）
+- (void)functionBarView:(KBFunctionBarView *)bar didTapLeftAtIndex:(NSInteger)index;
+/// 右侧 3 个按钮点击（index: 0~2）
+- (void)functionBarView:(KBFunctionBarView *)bar didTapRightAtIndex:(NSInteger)index;
+@end
+
 @interface KBFunctionBarView : UIView
 
+@property (nonatomic, weak, nullable) id<KBFunctionBarViewDelegate> delegate;
+
 /// 左侧4个按钮（懒加载创建，等宽水平排布）
 @property (nonatomic, strong, readonly) NSArray<UIButton *> *leftButtons;
 
diff --git a/CustomKeyboard/View/KBFunctionBarView.m b/CustomKeyboard/View/KBFunctionBarView.m
index 316fdc1..6b1815b 100644
--- a/CustomKeyboard/View/KBFunctionBarView.m
+++ b/CustomKeyboard/View/KBFunctionBarView.m
@@ -59,6 +59,7 @@
     for (NSInteger i = 0; i < 4; i++) {
         UIButton *btn = [self buildButtonWithTitle:(i < self.leftTitles.count ? self.leftTitles[i] : [NSString stringWithFormat:@"L%ld", (long)i])];
         btn.tag = 100 + i;
+        [btn addTarget:self action:@selector(onLeftTap:) forControlEvents:UIControlEventTouchUpInside];
         [self.leftContainer addSubview:btn];
         [btn mas_makeConstraints:^(MASConstraintMaker *make) {
             if (prev) {
@@ -84,6 +85,7 @@
         UIButton *btn = [self buildButtonWithTitle:(i < self.rightTitles.count ? self.rightTitles[i] : [NSString stringWithFormat:@"R%ld", (long)i])];
         btn.tag = 200 + i;
         [self.rightContainer addSubview:btn];
+        [btn addTarget:self action:@selector(onRightTap:) forControlEvents:UIControlEventTouchUpInside];
         [rightBtns addObject:btn];
     }
 
@@ -112,6 +114,22 @@
     self.rightButtonsInternal = rightBtns.copy;
 }
 
+#pragma mark - Actions
+
+- (void)onLeftTap:(UIButton *)sender {
+    NSInteger idx = sender.tag - 100;
+    if ([self.delegate respondsToSelector:@selector(functionBarView:didTapLeftAtIndex:)]) {
+        [self.delegate functionBarView:self didTapLeftAtIndex:idx];
+    }
+}
+
+- (void)onRightTap:(UIButton *)sender {
+    NSInteger idx = sender.tag - 200;
+    if ([self.delegate respondsToSelector:@selector(functionBarView:didTapRightAtIndex:)]) {
+        [self.delegate functionBarView:self didTapRightAtIndex:idx];
+    }
+}
+
 - (UIButton *)buildButtonWithTitle:(NSString *)title {
     UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];
     btn.layer.cornerRadius = 18;
diff --git a/CustomKeyboard/View/KBFunctionView.m b/CustomKeyboard/View/KBFunctionView.m
index 8cdcb69..32bcfbe 100644
--- a/CustomKeyboard/View/KBFunctionView.m
+++ b/CustomKeyboard/View/KBFunctionView.m
@@ -13,7 +13,7 @@
 
 static NSString * const kKBFunctionTagCellId = @"KBFunctionTagCellId";
 
-@interface KBFunctionView () <UICollectionViewDataSource, UICollectionViewDelegateFlowLayout>
+@interface KBFunctionView () <UICollectionViewDataSource, UICollectionViewDelegateFlowLayout, KBFunctionBarViewDelegate>
 // UI
 @property (nonatomic, strong) KBFunctionBarView *barViewInternal;
 @property (nonatomic, strong) KBFunctionPasteView *pasteViewInternal;
@@ -161,10 +161,24 @@ static NSString * const kKBFunctionTagCellId = @"KBFunctionTagCellId";
 - (KBFunctionBarView *)barViewInternal {
     if (!_barViewInternal) {
         _barViewInternal = [[KBFunctionBarView alloc] init];
+        _barViewInternal.delegate = self; // 顶部功能Bar事件下发到本View
     }
     return _barViewInternal;
 }
 
+#pragma mark - KBFunctionBarViewDelegate
+
+- (void)functionBarView:(KBFunctionBarView *)bar didTapLeftAtIndex:(NSInteger)index {
+    // 将事件继续透传给上层（如键盘控制器），用于切换界面或其它业务
+    if ([self.delegate respondsToSelector:@selector(functionView:didTapToolActionAtIndex:)]) {
+        [self.delegate functionView:self didTapToolActionAtIndex:index];
+    }
+}
+
+- (void)functionBarView:(KBFunctionBarView *)bar didTapRightAtIndex:(NSInteger)index {
+    // 右侧按钮点击，如收藏/宫格等，按需继续向外抛出（这里暂不定义单独协议方法，可在此内部处理或扩展）
+}
+
 - (KBFunctionPasteView *)pasteViewInternal {
     if (!_pasteViewInternal) {
         _pasteViewInternal = [[KBFunctionPasteView alloc] init];