iOS 輸入時鍵盤處理問題

在iOS的開發過程中，有時候需要處理鍵盤的彈出和收回。

以及鍵盤彈出收回時、view的處理

最正規的辦法，用通知

step 1：
在進入視圖的時候添加監視：（viewDidLoad什麼的）

    //監聽鍵盤的通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

step 2:
在鍵盤動作的時候移動視圖：

- (void)keyboardWillShow:(NSNotification *)notification {
    
    /*
     Reduce the size of the text view so that it's not obscured by the keyboard.
     Animate the resize so that it's in sync with the appearance of the keyboard.
     */
    NSDictionary *userInfo = [notification userInfo];
    
    // Get the origin of the keyboard when it's displayed.
    NSValue* aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
    // Get the top of the keyboard as the y coordinate of its origin in self's view's coordinate system. The bottom of the text view's frame should align with the top of the keyboard's final position.
    CGRect keyboardRect = [aValue CGRectValue];
    keyboardRect = [self.view convertRect:keyboardRect fromView:nil];
    
    CGFloat keyboardTop = keyboardRect.origin.y;
    CGRect newTextViewFrame = self.view.bounds;
    newTextViewFrame.size.height = keyboardTop - self.view.bounds.origin.y;
    
    // Get the duration of the animation.
    NSValue *animationDurationValue = [userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey];
    NSTimeInterval animationDuration;
    [animationDurationValue getValue:&animationDuration];
    
    // Animate the resize of the text view's frame in sync with the keyboard's appearance.
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:animationDuration];
    
    self.reportTableView.frame = newTextViewFrame;
    [UIView commitAnimations];
}

- (void)keyboardWillHide:(NSNotification *)notification {
    
    NSDictionary* userInfo = [notification userInfo];
    
    /*
     Restore the size of the text view (fill self's view).
     Animate the resize so that it's in sync with the disappearance of the keyboard.
     */
    NSValue *animationDurationValue = [userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey];
    NSTimeInterval animationDuration;
    [animationDurationValue getValue:&animationDuration];
    
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:animationDuration];
    
    self.reportTableView.frame = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width,[UIScreen mainScreen].bounds.size.height  - 55 - 64);
    
    [UIView commitAnimations];
}

step 3:
在退出視圖的時候註銷通知
viewDidUnload:

     [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];

step 4:
dealloc:

-(void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self name:nil object:nil];
}

這些代碼是摘自apple sample code KeyboardAccessory.

細節自己修改下就好了，比如那個reportTableView、CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width,[UIScreen mainScreen].bounds.size.height  - 55 - 64)