2

CustomKeyboard/KeyboardViewController.m

@@ -729,6 +729,20 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
 - (void)kb_applyTheme {
     KBSkinTheme *t = [KBSkinManager shared].current;
     UIImage *img = [[KBSkinManager shared] currentBackgroundImage];
+    if ([self kb_isDefaultKeyboardTheme:t]) {
+        CGSize size = self.bgImageView.bounds.size;
+        if (size.width <= 0 || size.height <= 0) {
+            [self.view layoutIfNeeded];
+            size = self.bgImageView.bounds.size;
+        }
+        if (size.width <= 0 || size.height <= 0) {
+            size = self.view.bounds.size;
+        }
+        if (size.width <= 0 || size.height <= 0) {
+            size = [UIScreen mainScreen].bounds.size;
+        }
+        img = [self kb_defaultGradientImageWithSize:size];
+    }
     NSLog(@"⌨️[Keyboard] apply theme id=%@ hasBg=%d", t.skinId, (img != nil));
     [self kb_logSkinDiagnosticsWithTheme:t backgroundImage:img];
     self.bgImageView.image = img;
@@ -752,6 +766,32 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
     }
 }
 
+- (BOOL)kb_isDefaultKeyboardTheme:(KBSkinTheme *)theme {
+    NSString *skinId = theme.skinId ?: @"";
+    if (skinId.length == 0 || [skinId isEqualToString:@"default"]) {
+        return YES;
+    }
+    return [skinId isEqualToString:kKBDefaultSkinId];
+}
+
+- (UIImage *)kb_defaultGradientImageWithSize:(CGSize)size {
+    if (size.width <= 0 || size.height <= 0) { return nil; }
+    CAGradientLayer *layer = [CAGradientLayer layer];
+    layer.frame = CGRectMake(0, 0, size.width, size.height);
+    layer.startPoint = CGPointMake(0.5, 0.0);
+    layer.endPoint = CGPointMake(0.5, 1.0);
+    layer.colors = @[
+        (id)[UIColor colorWithHex:0xDEDFE4].CGColor,
+        (id)[UIColor colorWithHex:0xD1D3DB].CGColor
+    ];
+
+    UIGraphicsBeginImageContextWithOptions(size, YES, 0);
+    [layer renderInContext:UIGraphicsGetCurrentContext()];
+    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
+    UIGraphicsEndImageContext();
+    return image;
+}
+
 - (void)kb_logSkinDiagnosticsWithTheme:(KBSkinTheme *)theme
                        backgroundImage:(UIImage *)image {
 #if DEBUG

CustomKeyboard/View/KBKeyboardView.m

@@ -128,6 +128,46 @@ static const CGFloat kKBLettersRow2EdgeSpacerMultiplier = 0.5;
     [self buildRow:self.row4 withRowConfig:rows[3]];
 }
 
+#pragma mark - Hit Test
+
+- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
+    UIView *hit = [super hitTest:point withEvent:event];
+    if ([hit isKindOfClass:[KBKeyButton class]]) {
+        return hit;
+    }
+    if (hit == self || hit == self.row1 || hit == self.row2 || hit == self.row3 || hit == self.row4) {
+        KBKeyButton *btn = [self kb_nearestKeyButtonForPoint:point];
+        if (btn) { return btn; }
+    }
+    return hit;
+}
+
+- (KBKeyButton *)kb_nearestKeyButtonForPoint:(CGPoint)point {
+    // 扩大按键的可点击区域，优先响应间隙点击（贴近系统键盘手感）。
+    CGFloat slopX = KBFit(8.0f);
+    CGFloat slopY = KBFit(4.0f);
+    KBKeyButton *best = nil;
+    CGFloat bestDistance = CGFLOAT_MAX;
+    NSArray<UIView *> *rows = @[self.row1, self.row2, self.row3, self.row4];
+    for (UIView *row in rows) {
+        for (UIView *view in row.subviews) {
+            if (![view isKindOfClass:[KBKeyButton class]]) { continue; }
+            KBKeyButton *btn = (KBKeyButton *)view;
+            CGRect frame = [self convertRect:btn.frame fromView:row];
+            CGRect hitFrame = CGRectInset(frame, -slopX, -slopY);
+            if (!CGRectContainsPoint(hitFrame, point)) { continue; }
+            CGFloat dx = point.x - CGRectGetMidX(frame);
+            CGFloat dy = point.y - CGRectGetMidY(frame);
+            CGFloat dist = (dx * dx) + (dy * dy);
+            if (dist < bestDistance) {
+                bestDistance = dist;
+                best = btn;
+            }
+        }
+    }
+    return best;
+}
+
 #pragma mark - Key Model Construction
 
 // 创建当前布局下各行的 KBKey 列表