我可以让UIPinchGestureRecognizer 处理程序用于缩放对象，但我不想缩放我想更改大小。例如，我有一个 UITextView 并且我已经附加了一个 UIPinchGestureRecognizer 手势，如果用户捏我想改变 textview 的宽度以匹配捏。我不想缩放它，所以UITextView 更大（缩放）。
【问题讨论】：
标签： iphone objective-c ipad pinch
你必须在swift中使用：
func pinchgsterAction(gesture:UIPinchGestureRecognizer){
if (gesture.state == UIGestureRecognizerState.Changed) {
let scale:CGFloat = gesture.scale
gesture.view.transform = CGAffineTransformScale(gesture.view.transform, scale, scale)
}
}
【讨论】：
我有四个处理文本字段收缩的例程。手势识别器是核心程序。它会查看选定的文本字段是否会从屏幕上被夹住，我不希望这样。如果不是，那么我告诉它用手势的比例捏自己。如果有多个选择，我会为那些不会捏住屏幕的人发送一个通知来捏自己。
//--------------------------------------------------------------------------------------------------------
// pinchElement
// Description: Called to di the element scale, in our case, we are adjusting the length.
//
//--------------------------------------------------------------------------------------------------------
- (void)pinchElement:(CGFloat)scale {
//Grab how big we are now
CGRect textFieldBounds = textField.bounds;
//Multiple the Scale of the Pinch by the Width to get our new width.
CGFloat newWidth = textFieldBounds.size.width * scale;
CGFloat widthChange = newWidth - textFieldBounds.size.width;
CGRect newBounds = CGRectMake(0, 0, newWidth, textFieldBounds.size.height );
[textField setBounds: newBounds];
[textField setCenter: CGPointMake(textField.center.x + widthChange/2, textField.center.y)] ;
[self contentSizeChanged];
}
//--------------------------------------------------------------------------------------------------------
// pinchOffScreen
// Description: Called to see if the Pinch Gesture will cause element to go off screen Gesture
//
//--------------------------------------------------------------------------------------------------------
- (BOOL)pinchOffScreen:(CGFloat)scale {
//Grab how big we are now
CGRect textFieldBounds = textField.bounds;
//Multiple the Scale of the Pinch by the Width to get our new width.
CGFloat newWidth = textFieldBounds.size.width * scale;
//Figure out our Change in Width so we can calculate our new Zen Center
CGRect newElementBounds = CGRectMake(0, 0, newWidth+ kElementFrameOffset*2 + kElementContentFrameOffset*2, textFieldBounds.size.height + kElementFrameOffset*2 + kElementContentFrameOffset*2);
//We want to be sure that we dont size beyond our bounds, find our Parent Origin.
CGRect elementBoundsInSuperView = [self convertRect:newElementBounds toView:[self superview]];
CGFloat xPosition = CGRectGetMidX(elementBoundsInSuperView);
CGFloat yPosition = CGRectGetMidY(elementBoundsInSuperView);
BOOL offScreen = [self calcOffEditorFromXposition:xPosition yPosition:yPosition fromBoundsInSuperView:elementBoundsInSuperView];
return offScreen;
}
//--------------------------------------------------------------------------------------------------------
// handlePinchGesture
// Description: Called when we get a Pinch Gesture
// We want to override the default scaling and set the width.
//
//--------------------------------------------------------------------------------------------------------
- (void)handlePinchGesture:(UIPinchGestureRecognizer *)gestureRecognizer {
if (IoUIDebug & IoUIDebugSelectorNames) {
NSLog(@"%@ - %@", INTERFACENAME, NSStringFromSelector(_cmd) );
}
// UIView *element = [gestureRecognizer view];
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan ) {
//We are resizing, Select ourself
[self selectSelf];
}
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan || [gestureRecognizer state] == UIGestureRecognizerStateChanged) {
NSSet *selectedElements = [[(IoScreenEditorViewController *)UIAppDelegate.ioMainViewController.currentViewController editorContentViewController] selectedElements];
BOOL aSelectedElementOffscreen = FALSE;
for (IoUIScreenElement* element in selectedElements) {
if ([element pinchOffScreen:[gestureRecognizer scale]]) {
aSelectedElementOffscreen = TRUE;
break;
}
}
if (!aSelectedElementOffscreen) {
[self pinchElement:[gestureRecognizer scale]];
// Let others know they are moving if they are selected
// Setup our data for the Notification
NSMutableDictionary *theUserInfo = [[[NSMutableDictionary alloc] initWithCapacity:1] autorelease];
[theUserInfo setObject:self forKey:@"ElementWithGesture"];
NSNumber * scaleAsNumber = [[NSNumber alloc] initWithFloat:[gestureRecognizer scale]];
[theUserInfo setValue:scaleAsNumber forKey:@"GestureScale"];
[theUserInfo setObject:gestureRecognizer forKey:@"TheGestureRecognizer"];
[scaleAsNumber release];
// Post the Group Rotation Notification.
[[NSNotificationCenter defaultCenter] postNotificationName:kNCSEGroupPinchGesture
object:nil
userInfo:theUserInfo];
}
[gestureRecognizer setScale:1];
}
if ([gestureRecognizer state] == UIGestureRecognizerStateEnded ) {
}
}
//--------------------------------------------------------------------------------------------------------
// groupHandlePinchGesture:
// Description: For a groupPinch Notification. Move it! within bounds of course
//
//--------------------------------------------------------------------------------------------------------
- (void) groupHandlePinchGesture:(NSNotification*)notification{
if (IoUIDebug & IoUIDebugSelectorNames) {
NSLog(@"%@ - %@", INTERFACENAME, NSStringFromSelector(_cmd) );
}
IoUIScreenElement *element = (IoUIScreenElement *) [[notification userInfo] objectForKey:@"ElementWithGesture"];
//UIRotationGestureRecognizer *gestureRecognizer = (UIRotationGestureRecognizer *) [[notification userInfo] objectForKey:@"TheGestureRecognizer"];
NSNumber *scaleAsNumber = [[notification userInfo] valueForKey:@"GestureScale"];
CGFloat scale = [scaleAsNumber floatValue];
if (IOFNOTEQUAL(self, element) & [self isSelected]){
[self pinchElement: scale];
}
}
【讨论】：
我也在做同样的事情。 如果我找到了怎么做，我会更新这篇文章。
试试这个，它对我有用（对于 UIView）：
- (IBAction)handlePinchGesture:(UIGestureRecognizer *)sender {
static CGRect initialBounds;
UIView *_view = sender.view;
if (sender.state == UIGestureRecognizerStateBegan)
{
initialBounds = _view.bounds;
}
CGFloat factor = [(UIPinchGestureRecognizer *)sender scale];
CGAffineTransform zt = CGAffineTransformScale(CGAffineTransformIdentity, factor, factor);
_view.bounds = CGRectApplyAffineTransform(initialBounds, zt);
return;
}
【讨论】：
我认为您想要做的只是将 textView 框架的宽度与手势识别器的比例相乘：
CGFloat scale = gestureRecognizer.scale;
CGRect newFrame = textView.frame;
newFrame.size = CGSizeMake(scale*newFrame.size.width, newFrame.size.height);
textView.frame = newFrame;
或者这不是你的意思吗？
【讨论】：