ios tableview 那些事（二十七）tableview 下滑手势关闭键盘
ios 7 简单方法
// 或者代码
self.tableView.keyboardDismissMode = UIScrollViewKeyboardDismissModeInteractive;
//下面 支持ios 7 一下版本
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController <UIGestureRecognizerDelegate>{
UITextField* textField;
int originalKeyboardY;
int originalLocation;
}
@end
<pre name="code" class="objc">
#import "ViewController.h"
#define kFingerGrabHandleHeight (20.0f)
@interface ViewController (private)
- (void)animateKeyboardReturnToOriginalPosition;
- (void)animateKeyboardOffscreen;
@end
@implementation ViewController
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
// always know which keyboard is selected
// 监听textField是否被选择
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textfieldWasSelected:) name:UITextFieldTextDidBeginEditingNotification object:nil];
// register for when a keyboard pops up
//监听键盘
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
//添加拖动手势
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGesture:)];
panRecognizer.delegate = self;
[self.view addGestureRecognizer:panRecognizer];
}
#pragma mark - Notification Handler
- (void)textfieldWasSelected:(NSNotification *)notification {
textField = notification.object;
}
- (void)keyboardWillShow:(NSNotification *)notification {
// To remove the animation for the keyboard dropping showing
// we have to hide the keyboard, and on will show we set it back.
keyboard.hidden = NO;
}
- (void)keyboardDidShow:(NSNotification *)notification {
if (keyboard)
return;
//Because we cant get access to the UIKeyboard throught the SDK we will just use UIView.
//UIKeyboard is a subclass of UIView anyways
//see discussion http://www.iphonedevsdk.com/forum/iphone-sdk-development/6573-howto-customize-uikeyboard.html
/* 遍历子视图*/
UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
for (int i = 0; i < [tempWindow.subviews count]; i++) {
UIView *possibleKeyboard = [tempWindow.subviews objectAtIndex:i];
if ([possibleKeyboard isKindOfClass:NSClassFromString(@"UIPeripheralHostView")]) {
keyboard = possibleKeyboard;
return;
}
}
}
#pragma mark - Gesture Handler
- (void)panGesture:(UIPanGestureRecognizer *)gestureRecognizer {
//触摸当前位置
CGPoint location = [gestureRecognizer locationInView:[self view]];
/*
velocityInView
像素平移速度
在指定的视图坐标系
*/
// velocity of the pan in pixels/second in the coordinate system of the specified view
CGPoint velocity = [gestureRecognizer velocityInView:self.view];
if (gestureRecognizer.state == UIGestureRecognizerStateBegan) {
//键盘y轴坐标，即高度
originalKeyboardY = keyboard.frame.origin.y;
;
}
if (gestureRecognizer.state == UIGestureRecognizerStateEnded) {
// y 轴方向拖动速度
if (velocity.y > 0) {
// 执行 键盘下落动画
[self animateKeyboardOffscreen];
} else {
[self animateKeyboardReturnToOriginalPosition];
}
return;
}
CGFloat spaceAboveKeyboard = CGRectGetHeight(self.view.bounds) - (CGRectGetHeight(keyboard.frame) + CGRectGetHeight(textField.frame)) + kFingerGrabHandleHeight;
if (location.y < spaceAboveKeyboard) {
return;
}
CGRect newFrame = keyboard.frame;
CGFloat newY = originalKeyboardY + (location.y - spaceAboveKeyboard);
newY = MAX(newY, originalKeyboardY);
newFrame.origin.y = newY;
[keyboard setFrame: newFrame];
}
#pragma mark -
- (void)animateKeyboardOffscreen {
[UIView animateWithDuration:0.3
delay:0
options:UIViewAnimationOptionCurveEaseOut
animations:^{
CGRect newFrame = keyboard.frame;
newFrame.origin.y = keyboard.window.frame.size.height;
[keyboard setFrame: newFrame];
}
completion:^(BOOL finished){
keyboard.hidden = YES;
[textField resignFirstResponder];
}];
}
- (void)animateKeyboardReturnToOriginalPosition {
[UIView beginAnimations:nil context:NULL];
CGRect newFrame = keyboard.frame;
newFrame.origin.y = originalKeyboardY;
[keyboard setFrame: newFrame];
[UIView commitAnimations];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
@end