iOS 根据父视图布局的方法 以及实现 Scrollview 拉动 遮罩输入框问题解决

1. iOS 根据父视图布局设定对应的x y点，然后设置当前视图的所在位置根据比例设置。

2. iOS 通过ScrollView 设置时限拉动效果 iOS 7.0 不需要减掉 顶部状态栏的高度 20， 但是7.0 以后需要减掉状态栏

3. iOS 遮罩文本框问题。

//
//  SecondController.m
//  HappyApp
//
//  Created by LiShijia on 14/11/19.
//  Copyright (c) 2014年 com.johnli. All rights reserved.
//

#import "SecondController.h"
#import "ViewController.h"
#import <UIKit/UIKit.h>

@implementation SecondController

-(void) viewDidLoad{

[self.view setBackgroundColor:[UIColor whiteColor]];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow) name:UIKeyboardWillShowNotification object:nil];

//    CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView)

//    [self.navigationController.toolbar setHidden:YES];

_scroller = [[UIScrollView alloc ] initWithFrame: self.view.bounds];

_scroller.frame = self.view.frame;

NSLog(@"before return the height %.f",_scroller.frame.size.height);

//    [_scroller setBackgroundColor: [UIColor redColor]];
CGSize size;

size = self.view.frame.size;
size.height = self.view.frame.size.height - 44.f - 19.f;

_scroller.contentSize = size;

NSLog(@"the frame bounds %f",self.navigationController.toolbar.frame.size.height);

_scroller.bounces = YES;

[self.view addSubview: _scroller];
[self addUser];
[self addPwd];
[self addPopButton];

}

//can key when you click return or finish
-(void) backUpTap{

[self.view endEditing:YES];

}

- (void) textFieldDidBeginEditing:(UITextField *)textField{

float viewY = textField.bounds.origin.y;
//
////    self.view.window.bounds

//        _scroller.contentSize = CGSizeMake(rect.size.width,rect.size.height + 10);
//    //原始滑动距离增加键盘高度
//        CGPoint pt = [textField convertPoint:CGPointMake(0, 0) toView:_scroller];
//    //把当前的textField的坐标映射到scrollview上
//
float navBarheight = self.navigationController.navigationBar.bounds.size.height;
NSLog(@"offset y %f",_scroller.contentOffset.y);

NSLog(@"view y %f",viewY);
NSLog(@"nav bar height %f",navBarheight);
if(_scroller.contentOffset.y-viewY+navBarheight<=0){
//        //判断最上面不要去滚动
////        [_scroller setContentOffset:CGPointMake(0, viewY-navBarheight) animated:YES];
[_scroller setContentOffset:CGPointMake(0, viewY-navBarheight) animated:YES];
}

}

//- (void) textFieldDidBeginEditing:(UITextField *)textField{
////    foucsTextField = textField;
//    float viewY = textField.bounds.origin.y;
//
////    self.view.window.bounds
//    CGRect rect = [UIScreen mainScreen].applicationFrame;
//    _scroller.contentSize = CGSizeMake(rect.size.width,rect.size.height +216);
//    //原始滑动距离增加键盘高度
//    CGPoint pt = [textField convertPoint:CGPointMake(0, 0) toView:_scroller];
//    //把当前的textField的坐标映射到scrollview上
//
//    float navBarheight = self.navigationController.navigationBar.
////    if(_scroller.contentOffset.y-viewY+navBarheight<=0){
//        //判断最上面不要去滚动
////        [_scroller setContentOffset:CGPointMake(0, viewY-navBarheight) animated:YES];
//    //[_scroller setContentOffset:CGPointMake(0, viewY-navBarheight) animated:YES];
////    }
//
//}
//
- (void) keyboardWillShow  {

//    NSLog(@"the keyboard will show %@",nofication);

NSLog(@" the keyboard will show");

//    CGPoint offet =   CGPointMake(0, self.view.bounds.origin.y + 216);
//
//    float offetHeigh = _userPwd.bounds.origin.y - 216;
//
//    NSLog(@"offer %f",_userPwd.bounds.origin.y);

//    [_scroller setContentOffset:offet animated:YES];

}

- (void) addUser{

//获取父视图对象的 x 以及 y 点 然后计算当前视图所排放的位置
CGRect urect = CGRectMake(_scroller.center.x * 0.2f, _scroller.center.y * 0.3f, 100, 50 );

UILabel * userLabel = [[UILabel alloc] initWithFrame:urect];
[userLabel setText:@"UserName"];
[_scroller addSubview:userLabel];

//    NSLayoutConstraint *layout = [NSLayoutConstraint constraintWithItem:userLabel attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:_scroller attribute:NSLayoutAttributeCenterX multiplier:1.0f constant:0.0];
//

NSLog(@"ssssssss  %.f",userLabel.frame.origin.y);

urect.origin.x = _scroller.center.x * 0.8f;
urect.origin.y = _scroller.center.y * 0.35f;
urect.size.height = 20;
urect.size.width = _scroller.frame.size.width * 0.54f;;
UITextField * userField = [[UITextField alloc] initWithFrame: urect];
[userField setBackgroundColor:[UIColor redColor]];
userField.borderStyle = UITextBorderStyleRoundedRect;

//    [userField addTarget:self action:@selector(backUpTap) forControlEvents:UIControlEventEditingDidEndOnExit];

userField.delegate = self;

[_scroller addSubview:userField];

}

//add user pwd lable
-(void) addPwd{

CGRect prect = CGRectMake(_scroller.center.x * 0.2f, _scroller.center.y * 0.5f, 150, 50 );

UILabel * pwdLable = [[UILabel alloc] initWithFrame:prect];
[pwdLable setText:@"Password"];
[_scroller addSubview:pwdLable];

prect.origin.x = _scroller.center.x;
prect.origin.y = _scroller.center.y * 0.55f;
prect.size.height = 20;
prect.size.width = 100;

_userPwd = [[UITextField alloc] initWithFrame:prect];
[_userPwd setBackgroundColor:[UIColor redColor]];
_userPwd.secureTextEntry = YES;
_userPwd.borderStyle = UITextBorderStyleRoundedRect;
_userPwd.delegate = self;
//    [userPwd addTarget:self action:@selector(backUpTap) forControlEvents:UIControlEventEditingDidEndOnExit];
[_scroller addSubview:_userPwd];
}

- (void) addPopButton{

UIButton * popButton = [[UIButton alloc] initWithFrame:CGRectMake(100, 400, 100, 50)];
[popButton setBackgroundColor:[UIColor redColor]];
[popButton setTitle:@"Login" forState:UIControlStateNormal];
[popButton addTarget:self action:@selector(popLastController) forControlEvents:UIControlEventTouchUpInside];
[_scroller addSubview:popButton];

}

-(BOOL) textFieldShouldReturn:(UITextField *) textField {

NSLog(@"you are clicing the return key");

[self.view endEditing:YES];

//开始动画
[UIView beginAnimations:nil context:nil];
//设定动画持续时间
[UIView setAnimationDuration:0.3];
_scroller.frame = self.view.frame;

NSLog(@"after return the height %.f",_scroller.frame.size.height);

CGSize size;
size = self.view.frame.size;
size.height = self.view.frame.size.height - 44.f - 19.f;

//    [_scroller setContentSize: size];

//动画结束
[UIView commitAnimations];

return YES;
}

- (void) popLastController{

//[self.navigationController popViewControllerAnimated:YES];

//ViewController * vc = (ViewController *)[self.navigationController.viewControllers objectAtIndex:0];

[self.navigationController popToRootViewControllerAnimated:YES];
//    [self.navigationController popToViewController:vc animated:YES];

}

@end