iOS 实现输入框跟随键盘自动上移正确姿势 支持iOS7

• 不多说先上效果图:

刚开始上一个同学对于键盘上移的代码是这么写的:

- (void) animateTextField: (UITextField*) textField up: (BOOL) up

{

int movementDistance = 50;

if (up)

{

CGPoint postion = [textField convertPoint:textField.frame.origin toView:nil];

movementDistance = 80 - (self.view.frame.size.height - postion.y - textField.frame.size.height);

if (movementDistance < 0)

{

return;

}

}

const float movementDuration = 0.3f; // tweak as needed

[UIView beginAnimations: @"anim" context: nil];

[UIView setAnimationBeginsFromCurrentState: YES];

[UIView setAnimationDuration: movementDuration];

CGRect frame = self.view.frame;

frame.origin.y = up?-movementDistance:64;

self.view.frame = frame;

[UIView commitAnimations];

}

其实也没错 但是问题出现在键盘没有挡住我的文本框的时候 也会自动上移 并且没有把代码抽成公共的代码 只要有文本框的地方都这么写 非常不好维护,于是我就自己把他抽成一个工具类去使用。至于好处 我就不说了.

实现思路

• 观察键盘的弹起与收回，当弹起的键盘会遮挡住输入框时，将输入框跟随键盘一并上移合适的距离，当键盘收回时，输入框回到原始状态。

注意的问题

• 如何动态获取键盘的高度,因为每个键盘的类型不一样的,这样会导致键盘的高度不可能是一个固定的值.参考:iOS键盘高度的获取

• 还得适配iOS7 支持横竖屏幕 .原因：在ios7上，键盘的frame，系统是按照竖屏状态下window坐标系来计算的，并不考虑旋转的因素，因此在横屏下得到的键盘frame是错误的。受此影响的还有横屏时获取屏幕宽高[UIScreen mainScreen].bounds，也会有这样的问题。这种情况我们不仅无法正确得到键盘的frame，而且输入框相对于window的坐标计算结果也是错误的

• 因此在ios7上，键盘上端的Y坐标以及输入框下端相对于window的Y坐标需要单独处理。键盘上端的Y坐标可以通过屏幕高度减键盘高度得到。我们通过下面的方法获取键盘上端的Y坐标。

.h文件

@interface TTKKeyBoardTool : NSObject

/**

*  实现输入框跟随键盘自动上移

*

*  @param animationOfTextField    正在输入的文本框

*  @param inView  当前view

*/

+ (void)animationOfTextField:(UITextField *)textField

inView:(UIView *)view;

@end




.m文件 注释写️很清楚 我也不多bb了

+ (void)animationOfTextField:(UITextField *)textField inView:(UIView *)view{

__weak typeof(self) weakSelf = self;

[[[NSNotificationCenter defaultCenter] rac_addObserverForName:@"UIKeyboardWillShowNotification" object:nil] subscribeNext:^(id x) {

UIView *focusView = nil;

if ([textField isFirstResponder]) {

focusView = textField;

}

NSDictionary *userInfo = [x userInfo];

if (focusView) {

//获取键盘弹出的时间

double duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];

//获取键盘上端Y坐标

CGFloat keyboardY = [weakSelf getKeyboardY:userInfo];

//获取输入框下端相对于window的Y坐标

CGPoint tmp = [weakSelf getViewOriginPointToWindow:focusView];

CGFloat inputBoxY = tmp.y + focusView.frame.size.height;

//计算二者差值

CGFloat ty = keyboardY - inputBoxY;

NSLog(@"position keyboard: %f, inputbox: %f, ty: %f", keyboardY, inputBoxY, ty);

//差值小于0，做平移变换

[UIView animateWithDuration:duration animations:^{

if (ty < 0) {

view.transform = CGAffineTransformMakeTranslation(0, ty);

}

}];

}

}];

[[[NSNotificationCenter defaultCenter] rac_addObserverForName:@"UIKeyboardWillHideNotification" object:nil] subscribeNext:^(id x) {

NSDictionary *userInfo = [x userInfo];

//获取键盘弹出的时间

double duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];

//还原

[UIView animateWithDuration:duration animations:^{

view.transform = CGAffineTransformMakeTranslation(0, 0);

}];

}];

}

适配iOS7并且支持横竖屏幕 动态获取键盘的高度代码

+ (CGFloat)getKeyboardY:(NSDictionary *)userInfo

{

CGFloat screenHeight;

CGFloat keyboardY = 0;

CGFloat keyboardHeight = 0;

UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;

if (( [[[UIDevice currentDevice] systemVersion] floatValue]<8)  && UIInterfaceOrientationIsLandscape(orientation))

{

screenHeight = [[UIScreen mainScreen] bounds].size.width;

keyboardHeight = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue].size.width;

keyboardY = screenHeight - keyboardHeight;

}

else if (( [[[UIDevice currentDevice] systemVersion] floatValue]<8)  && UIInterfaceOrientationIsPortrait(orientation)) {

screenHeight = [[UIScreen mainScreen] bounds].size.height;

keyboardHeight = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;

keyboardY = screenHeight - keyboardHeight;

}

else {

keyboardY = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue].origin.y;

}

return keyboardY;

}

+ (CGPoint)getViewOriginPointToWindow:(UIView *)view

{

CGPoint origin;

if ([[[UIDevice currentDevice] systemVersion] floatValue] < 8) {

CGPoint focusViewPoint = [view convertPoint:CGPointZero toView:nil];

UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;

if (orientation == UIInterfaceOrientationLandscapeLeft) {

origin.y = focusViewPoint.x;

origin.x = [[[UIApplication sharedApplication] delegate] window].bounds.size.height - focusViewPoint.y;

}

else if (orientation == UIInterfaceOrientationLandscapeRight) {

origin.y = [[[UIApplication sharedApplication] delegate] window].bounds.size.width - focusViewPoint.x;

origin.x = focusViewPoint.y;

}

else if (orientation == UIInterfaceOrientationPortraitUpsideDown) {

origin.y = [[[UIApplication sharedApplication] delegate] window].bounds.size.height - focusViewPoint.y;

origin.x = [[[UIApplication sharedApplication] delegate] window].bounds.size.width - focusViewPoint.x;

}

else {

origin = focusViewPoint;

}

}

else {

CGRect rect = [view convertRect:view.bounds toView:[[[UIApplication sharedApplication] delegate] window]];

origin = rect.origin;

}

return origin;

}   

如何调用:在你点击文本框的时候去掉用.

- (void)textFieldDidBeginEditing:(UITextField *)textField

{

[TTKKeyBoardTool animationOfTextField:textField inView:self.view];

}