#import "ViewController.h"
#import "UIView+FrameExtension.h" // 可以自己寫，以后用著方便
#define kDeviceHeight [UIScreen mainScreen].bounds.size.height
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// 設(shè)置視圖的背景色
self.view.backgroundColor = [UIColor lightGrayColor];
// 添加第一個文本框 假定位置
UITextField *firstField = [[UITextField alloc]initWithFrame:CGRectMake(50, 300, 200, 40)];
firstField.backgroundColor = [UIColor whiteColor];
[self.view addSubview:firstField];
// 添加第一個文本框
UITextField *secondField = [[UITextField alloc]initWithFrame:CGRectMake(firstField.x, firstField.bottom + 50, firstField.width , firstField.height)];
[self.view addSubview:secondField];
secondField.backgroundColor = [UIColor whiteColor];
// 注冊鍵盤顯示的通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(showKeyboard:) name:UIKeyboardWillShowNotification object:nil];
// 注冊鍵盤隱藏的通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(hideKeyboard: ) name:UIKeyboardWillHideNotification object:nil];
}
// 鍵盤彈出時執(zhí)行這個方法，
-(void)showKeyboard:(NSNotification *)notification{
// 定義一個文本框，指向正在編輯的文本框，也就是彈出鍵盤的文本框
UITextField *txtField;
// 今次遍歷當(dāng)前視圖的所有子視圖， subViews數(shù)組保存的是當(dāng)前視圖所有的子視圖
for (UIView *subView in self.view.subviews) {
// 如果這個子視圖是一個文本框的話，isKindOfClass方法可以判斷某個變量是不是某個類型的變量
if ([subView isKindOfClass:[UITextField class]]) {
// 先把這個子視圖轉(zhuǎn)化為文本框
UITextField *tempField = (UITextField *)subView;
// 再判斷這個文本框是不是正在編輯
if (tempField.isEditing ) {
// 如果這個文本框正在編輯，就是我要找的文本框，中斷循環(huán)
txtField = tempField;
break;
}
}
}
NSLog(@"%@", notification);
// 獲取通知的userInfo屬性
NSDictionary *userInfoDict = notification.userInfo;
// 通過鍵盤通知的userInfo屬性獲取鍵盤的bounds
NSValue *value = [userInfoDict objectForKey:UIKeyboardBoundsUserInfoKey];
// 鍵盤的大小
CGSize keyboardSize = [value CGRectValue].size;
// 鍵盤高度
CGFloat keyboardHeight = keyboardSize.height;
CGFloat offset = kDeviceHeight - keyboardHeight - txtField.bottom ;
if (offset < 0 ) { //這種情況下需要上移
offset = offset - 10 ; //保存上移的高度
[UIView animateWithDuration:0.5 animations:^{
self.view.transform = CGAffineTransformMakeTranslation(0, offset );
}];
}
}
-(void)hideKeyboard:(NSNotification *)notification{
[UIView animateWithDuration:2 animations:^{
self.view.transform = CGAffineTransformIdentity;
}];
}
// 點擊屏幕空白時隱藏鍵盤
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
[self.view endEditing:YES];
}
@end