优化，修复#12

GKCycleScrollView.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name                = 'GKCycleScrollView'
-  s.version             = '1.0.5'
+  s.version             = '1.0.6'
   s.summary             = '一个轻量级的自定义轮播图组件'
   s.homepage            = 'https://github.com/QuintGao/GKCycleScrollView'
   s.license             = { :type => "MIT", :file => "LICENSE" }

GKCycleScrollView/GKCycleScrollView.h

@@ -34,7 +34,8 @@ typedef NS_ENUM(NSUInteger, GKCycleScrollViewScrollDirection) {
 @protocol GKCycleScrollViewDelegate <NSObject>
 
 @optional
-// 返回自定义cell尺寸
+/// 返回自定义cell尺寸
+/// @param cycleScrollView cycleScrollView description
 - (CGSize)sizeForCellInCycleScrollView:(GKCycleScrollView *)cycleScrollView;
 
 // cell滑动时调用
@@ -43,6 +44,12 @@ typedef NS_ENUM(NSUInteger, GKCycleScrollViewScrollDirection) {
 // cell点击时调用
 - (void)cycleScrollView:(GKCycleScrollView *)cycleScrollView didSelectCellAtIndex:(NSInteger)index;
 
+/// scrollView滚动中的回调
+/// @param cycleScrollView cycleScrollView对象
+/// @param fromIndex 正在滚动中，相对位置处于左边或上边的index，根据direction区分
+/// @param toIndex 正在滚动中，相对位置处于右边或下边的index，根据direction区分
+/// @param ratio 从左到右或从上到下计算的百分比，根据direction区分
+- (void)cycleScrollView:(GKCycleScrollView *)cycleScrollView scrollingFromIndex:(NSInteger)fromIndex toIndex:(NSInteger)toIndex ratio:(CGFloat)ratio;
 #pragma mark - UIScrollViewDelegate 相关
 - (void)cycleScrollView:(GKCycleScrollView *)cycleScrollView willBeginDragging:(UIScrollView *)scrollView;
 - (void)cycleScrollView:(GKCycleScrollView *)cycleScrollView didScroll:(UIScrollView *)scrollView;

GKCycleScrollView/GKCycleScrollView.m

@@ -329,6 +329,7 @@ - (void)updateScrollViewAndCellSize {
 }
 
 - (void)setupCellsWithContentOffset:(CGPoint)offset {
+    if (self.showCount == 0) return;
     if (self.cellSize.width <= 0 || self.cellSize.height <= 0) return;
     //计算_visibleRange
     CGPoint startPoint = CGPointMake(offset.x - self.scrollView.frame.origin.x, offset.y - self.scrollView.frame.origin.y);
@@ -413,6 +414,7 @@ - (void)setupCellsWithContentOffset:(CGPoint)offset {
 }
 
 - (void)updateVisibleCellAppearance {
+    if (self.showCount == 0) return;
     if (self.cellSize.width <= 0 || self.cellSize.height <= 0) return;
 
     switch (self.direction) {
@@ -438,7 +440,7 @@ - (void)updateVisibleCellAppearance {
                     leftRightInset = adjustLeftRightMargin * delta / self.cellSize.width;
                     topBottomInset = adjustTopBottomMargin * delta / self.cellSize.width;
 
-                    NSInteger index = i % self.realCount;
+                    NSInteger index = self.realCount == 0 ? 0 : i % self.realCount;
                     if (index == self.currentSelectIndex) {
                         [self.scrollView bringSubviewToFront:cell];
                     }
@@ -496,7 +498,7 @@ - (void)updateVisibleCellAppearance {
                     leftRightInset = adjustLeftRightMargin * delta / self.cellSize.height;
                     topBottomInset = adjustTopBottomMargin * delta / self.cellSize.height;
 
-                    NSInteger index = i % self.realCount;
+                    NSInteger index = self.realCount == 0 ? 0 : i % self.realCount;
                     if (index == self.currentSelectIndex) {
                         [self.scrollView bringSubviewToFront:cell];
                     }
@@ -699,9 +701,7 @@ - (void)scrollViewDidScroll:(UIScrollView *)scrollView{
         [self handleCellScrollWithIndex:index];
     }
 
-    if ([self.delegate respondsToSelector:@selector(cycleScrollView:didScroll:)]) {
-        [self.delegate cycleScrollView:self didScroll:scrollView];
-    }
+    [self handleScrollViewDidScroll:scrollView];
 }
 
 - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
@@ -765,6 +765,58 @@ - (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView {
     }
 }
 
+- (void)handleScrollViewDidScroll:(UIScrollView *)scrollView {
+    if ([self.delegate respondsToSelector:@selector(cycleScrollView:didScroll:)]) {
+        [self.delegate cycleScrollView:self didScroll:scrollView];
+    }
+
+    if ([self.delegate respondsToSelector:@selector(cycleScrollView:scrollingFromIndex:toIndex:ratio:)]) {
+        BOOL isFirstRevirse = NO; // 是否在第一个位置反向滑动
+        CGFloat ratio = 0;   // 滑动百分比
+        if (self.direction == GKCycleScrollViewScrollDirectionHorizontal) {
+            CGFloat offsetX = scrollView.contentOffset.x;
+            CGFloat maxW = self.realCount * scrollView.bounds.size.width;
+
+            CGFloat changeOffsetX = self.isInfiniteLoop ? (offsetX - maxW) : offsetX;
+            if (changeOffsetX < 0) {
+                changeOffsetX = -changeOffsetX;
+                isFirstRevirse = YES;
+            }
+            ratio = (changeOffsetX / scrollView.bounds.size.width);
+        }else if (self.direction == GKCycleScrollViewScrollDirectionVertical) {
+            CGFloat offsetY = scrollView.contentOffset.y;
+            CGFloat maxW = self.realCount * scrollView.bounds.size.height;
+
+            CGFloat changeOffsetY = self.isInfiniteLoop ? (offsetY - maxW) : offsetY;
+            if (changeOffsetY < 0) {
+                changeOffsetY = -changeOffsetY;
+                isFirstRevirse = YES;
+            }
+            ratio = (changeOffsetY / scrollView.bounds.size.height);
+        }
+        if (ratio > self.realCount || ratio < 0) return; // 越界，不作处理
+        ratio = MAX(0, MIN(self.realCount, ratio));
+        NSInteger baseIndex = floor(ratio);
+        if (baseIndex + 1 > self.realCount) {
+            // 右边越界了
+            baseIndex = 0;
+        }
+        CGFloat remainderRatio = ratio - baseIndex;
+        if (remainderRatio <= 0 || remainderRatio >= 1) return;
+        NSInteger toIndex = 0;
+        if (isFirstRevirse) {
+            baseIndex = self.realCount - 1;
+            toIndex = 0;
+            remainderRatio = 1 - remainderRatio;
+        }else if (baseIndex == self.realCount - 1) {
+            toIndex = 0;
+        }else {
+            toIndex = baseIndex + 1;
+        }
+        [self.delegate cycleScrollView:self scrollingFromIndex:baseIndex toIndex:toIndex ratio:remainderRatio];
+    }
+}
+
 #pragma mark - 懒加载
 - (UIScrollView *)scrollView {
     if (!_scrollView) {

GKCycleScrollViewDemo/GKCycleScrollViewDemo/Demo/GKDemo001ViewController.m

@@ -44,6 +44,7 @@ - (void)viewDidLoad {
     // 默认样式：无缩放，自动轮播，无限轮播
     GKCycleScrollView *cycleScrollView1 = [[GKCycleScrollView alloc] initWithFrame:CGRectMake(0, GK_STATUSBAR_NAVBAR_HEIGHT, kScreenW, 130)];
     cycleScrollView1.dataSource = self;
+    cycleScrollView1.delegate = self;
     [self.view addSubview:cycleScrollView1];
     self.cycleScrollView1 = cycleScrollView1;
 
@@ -188,6 +189,7 @@ - (GKCycleScrollViewCell *)cycleScrollView:(GKCycleScrollView *)cycleScrollView
 
 #pragma mark - GKCycleScrollViewDelegate
 - (CGSize)sizeForCellInCycleScrollView:(GKCycleScrollView *)cycleScrollView {
+    if (cycleScrollView == self.cycleScrollView1) return CGSizeMake(kScreenW, 130);
     if (cycleScrollView == self.cycleScrollView5) return CGSizeMake(kScreenW, 40);
     return CGSizeMake(kScreenW - 100, 130);
 }
@@ -205,4 +207,10 @@ - (void)cycleScrollView:(GKCycleScrollView *)cycleScrollView didSelectCellAtInde
     NSLog(@"cell点击，index=%zd", index);
 }
 
+- (void)cycleScrollView:(GKCycleScrollView *)cycleScrollView scrollingFromIndex:(NSInteger)fromIndex toIndex:(NSInteger)toIndex ratio:(CGFloat)ratio {
+    if (cycleScrollView != self.cycleScrollView1) return;
+
+    NSLog(@"fromIndex:%zd,toIndex:%zd,ratio:%f", fromIndex, toIndex, ratio);
+}
+
 @end

README.md

@@ -65,6 +65,7 @@ cycleScrollView.dataSource = self;
 
 ## 版本更新
 
+* 2021.02.24 1.0.6 优化代码，防止crash，增加滑动百分比代理
 * 2021.02.22 1.0.5 修复xib加载时可能导致的布局错乱问题
 * 2021.01.27 1.0.3 修复某些情况下cell不能滑动的bug
 * 2020.12.07 1.0.1 修复cell子视图点击处理bug