新的一天，新的问题！
我一直在开发一个应用程序，该应用程序需要在用户触摸屏幕时显示用户手指所在的圆圈。
我遵循了一个关于子类化 UIWindow的教程，我的评论解释了如果您使用 Storyboards 和 ARC，如何传递这些内容。
我正在使用以下代码（基于本教程）来显示触摸指示器：
#pragma mark - Touch Events
- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event {
NSArray *subviews = [self.webView subviews];
for (UIView *view in subviews)
{
// Check if view is scrollview
if ([view isKindOfClass:[UserTouchImageView class]])
{
[view removeFromSuperview];
}
}
// Enumerate over all the touches and draw a red dot on the screen where the touches were
[touches enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
// Get a single touch and it's location
UITouch *touch = obj;
CGPoint touchPoint = [touch locationInView:self.webView];
// Add touch indicator
UserTouchImageView *touchView = [[UserTouchImageView alloc] initWithFrame:CGRectMake(touchPoint.x -15, touchPoint.y -15, 30, 30)];
[self.webView addSubview:touchView];
}];
NSLog(@"Touches began");
}
- (void) touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event {
NSArray *subviews = [self.webView subviews];
for (UIView *view in subviews)
{
// Check if view is scrollview
if ([view isKindOfClass:[UserTouchImageView class]])
{
[view removeFromSuperview];
}
}
// Enumerate over all the touches and draw a red dot on the screen where the touches were
[touches enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
// Get a single touch and it's location
UITouch *touch = obj;
CGPoint touchPoint = [touch locationInView:self.webView];
// Draw a red circle where the touch occurred
UserTouchImageView *touchView = [[UserTouchImageView alloc] initWithFrame:CGRectMake(touchPoint.x -15, touchPoint.y -15, 30, 30)];
[self.webView addSubview:touchView];
}];
NSLog(@"Touches moved");
}
- (void) touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event {
NSArray *subviews = [self.webView subviews];
for (UIView *view in subviews)
{
// Check if view is scrollview
if ([view isKindOfClass:[UserTouchImageView class]])
{
[UIView animateWithDuration:0.5f
animations:^{
view.alpha = 0.0;
}
completion:^(BOOL finished) {
[view removeFromSuperview];
}];
}
}
NSLog(@"Touches ended");
}
- (void) touchesCancelled:(NSSet*)touches withEvent:(UIEvent*)event {
NSArray *subviews = [self.webView subviews];
for (UIView *view in subviews)
{
// Check if view is scrollview
if ([view isKindOfClass:[UserTouchImageView class]])
{
[view removeFromSuperview];
}
}
NSLog(@"Touches cancelled");
}
UserTouchImageView 是 UIImageView 的子类，默认更改为：
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
self.image = [UIImage imageNamed:@"greyCircle.png"];
self.alpha = 0.5f;
}
return self;
}
我已经在没有 UIWebview 的情况下测试了这段代码（用 替换self.webView）self.view，它工作正常，在我单击并拖动的地方绘制圆圈，然后在我释放按钮时淡出。
我还成功地实例化了 UserTouchImageView 并将其从 viewController 的viewDidLoad方法添加到 webView。
一旦我将 UIWebview 与上面的代码一起放入，同一行 ( [self.webView addSubview:touchView];) 就不起作用了。我仍然将 NSLog 消息发送到控制台，但子视图没有明显添加。
谁能帮我弄清楚为什么这没有出现？是否有任何其他代码我需要注意，或者我不能这样做的任何原因？
非常感谢！
编辑
到目前为止，我已经上传了我的源代码(MediaFire)
编辑 2
我添加了以下两种方法：
-(void)listWebViewSubViews
{
NSLog(@"BEGIN LISTING SUBVIEWS");
for (UIView *view in [self.webView subviews]) {
NSLog(@"Subview: %@", view.description);
}
NSLog(@"END LISTING SUBVIEWS");
}
-(void)view:(UIView *)view addTouchIndicatorWithCentreAtPoint:(CGPoint)point
{
NSLog(@"View: %@, x: %f, y: %f", view.description, point.x, point.y);
// Add touch indicator
UserTouchImageView *touchView = [[UserTouchImageView alloc] initWithFrame:CGRectMake(point.x -15, point.y -15, 30, 30)];
[view addSubview:touchView];
}
这些是从 UIWebView 外部的两个按钮和 touchesbegan 方法中调用的：
- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event {
NSArray *subviews = [self.webView subviews];
for (UIView *view in subviews)
{
if ([view isKindOfClass:[UserTouchImageView class]])
{
[view removeFromSuperview];
}
}
[touches enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
UITouch *touch = obj;
CGPoint touchPoint = [touch locationInView:self.webView];
[self view:self.webView addTouchIndicatorWithCentreAtPoint:touchPoint];
[self listWebViewSubViews];
}];
NSLog(@"Touches began");
}
日志记录似乎表明，在 touches started 方法中引用的 webviewself.webView 是一个完全独立的实例，而不是从两个按钮引用的实例。我可以通过按钮添加多个子视图，然后列出它们，它们都显示在日志中，但是当我点击模拟器时，这些额外的子视图都没有列出。
有谁知道 UIWebView 中有任何特殊功能在触摸事件上有重复的实例？