iOS獲取鍵盤(pán)高度
（1）注冊(cè)監(jiān)聽(tīng)，監(jiān)聽(tīng)鍵盤(pán)的彈出
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(handleKeyBoardNotification:)
name:UIKeyboardWillShowNotification
object:nil];
（2）在監(jiān)聽(tīng)的觸發(fā)方法當(dāng)中，使用如下代碼獲取鍵盤(pán)高度
-(void)handleKeyBoardNotification:(NSNotification *)sender {
// 獲取鍵盤(pán)高度，關(guān)鍵的一句
NSValue *value = [sender.userInfo objectForKey:@"UIKeyboardBoundsUserInfoKey"];
CGSize keyboardSize = [value CGRectValue].size;
float keyboardHeight = keyboardSize.height;
}
