ios UITextField 以及键盘显示总结

//
//  MyUITextFieldViewController.m
//  2020082901Test
//
//  Created by 张亚楠 on 2021/1/25.
//  Copyright © 2021 张亚楠. All rights reserved.
//

#import "MyUITextFieldViewController.h"
#import <Masonry.h>
@interface MyUITextFieldViewController ()<UITextFieldDelegate>
@property (nonatomic, strong, readwrite) UITextField *textField;
@property (nonatomic, strong, readwrite) UITextField *centerTextField;
@property (nonatomic, strong, readwrite) UITextField *bottomTextField;
@property (nonatomic, copy) NSMutableArray *textFieldArray;
@end

@implementation MyUITextFieldViewController
- (NSMutableArray *)textFieldArray {
    if (_textFieldArray == nil) {
        NSMutableArray *mArray = [NSMutableArray array];
        [mArray addObject:self.textField];
        [mArray addObject:self.centerTextField];
        [mArray addObject:self.bottomTextField];
        _textFieldArray = mArray;
    }
    return _textFieldArray;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    self.textField = [[UITextField alloc]init];
    self.centerTextField = [[UITextField alloc]init];
    self.bottomTextField = [[UITextField alloc]init];
    [self.view addSubview:self.textField];
    [self.view addSubview:self.centerTextField];
    [self.view addSubview:self.bottomTextField];

    [self.textField mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.view).offset(120);
        make.left.mas_equalTo(20);
        make.right.mas_equalTo(-20);
        make.height.mas_equalTo(40);
    }];
    [self.centerTextField mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.view).offset(400);
        make.left.mas_equalTo(20);
        make.right.mas_equalTo(-20);
        make.height.mas_equalTo(40);
    }];
    [self.bottomTextField mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(self.view).offset(600);
        make.left.mas_equalTo(20);
        make.right.mas_equalTo(-20);
        make.height.mas_equalTo(40);
    }];
    
    [self initTextField:self.textField leftImage: [UIImage imageNamed:@"蓝色我的图标"]];
    [self initTextField:self.centerTextField leftImage: [UIImage imageNamed:@"蓝色我的图标"]];
    [self initTextField:self.bottomTextField leftImage: [UIImage imageNamed:@"蓝色我的图标"]];

    //设置returnKeyType，可以直接跳转到下一个填空
    for (int i = 0; i < self.textFieldArray.count; i++) {
        UITextField *textField =   self.textFieldArray[i];
        textField.delegate = self;
        textField.tag = i;
        textField.returnKeyType = i == (self.textFieldArray.count - 1) ? UIReturnKeyDefault : UIReturnKeyNext;
    }
    //添加键盘监听事件
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(yjd_keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
}

- (void)yjd_keyboardWillShow:(NSNotification *)notifi
{
    //获取键盘的高度
    NSDictionary *userInfo = [notifi userInfo];
    NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGFloat keyboardHeight = [aValue CGRectValue].size.height;//键盘的高度
    //获取键盘动画时间
    CGFloat time = [notifi.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    //获取当前第一响应状态的输入框
    UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
    UIView *view = [keyWindow performSelector:@selector(firstResponder)];

    //输入框在当前屏幕的坐标y
    CGFloat maxY =  CGRectGetMaxY([view convertRect:view.bounds toView:[[[UIApplication sharedApplication] delegate] window]]);

    //判断是非遮挡当前输入框，小于0遮挡，大于或等于0没有
    CGFloat map = [UIScreen mainScreen].bounds.size.height  - maxY - keyboardHeight;
    NSLog(@"map = %f", map);
    if (map < 0) {
        [UIView animateWithDuration:time animations:^{
            self.view.transform = CGAffineTransformTranslate(self.view.transform, 0, map);
        }];
    }
}

//点击键盘return
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    if (textField.returnKeyType == UIReturnKeyNext) {
        NSLog(@"textFieldShouldReturn");
        UITextField *nextTextField = (UITextField *)[self.view viewWithTag:textField.tag + 1];
        [textField endEditing:YES];
        [nextTextField becomeFirstResponder];
    } else {
        NSLog(@"textFieldShouldReturn===transform");
        [self endEdit];
    }
    return YES;
}

//隐藏键盘
- (void)endEdit {
    [self.view endEditing:YES];
    self.view.transform = CGAffineTransformIdentity;
}
//点击其他位置隐藏键盘
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [self endEdit];
}

- (void)dealloc
{
    //移除通知
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
}

//初始化UITextField
- (void)initTextField:(UITextField *)textField leftImage:(UIImage *)leftImage{
    //设置边框
    textField.layer.borderColor = [UIColor grayColor].CGColor;
    textField.layer.borderWidth = 1.0;
    textField.layer.cornerRadius = 10;

    //设置内边距、paddingTop、paddingLeft、paddingBottom、paddingRight
//    [textField setValue:[NSNumber numberWithInt:20] forKey:@"paddingLeft"];
   
    UIView *leftView=[[UIView alloc]initWithFrame:CGRectMake(0, 0, 40, 40)];
    
    //设置左侧“返回”
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 8, 25, 24)];
    imageView.image =leftImage;
    [leftView addSubview:imageView];
    textField.leftView = leftView;

    
    //设置显示模式
    textField.leftViewMode = UITextFieldViewModeAlways;
    textField.clearButtonMode = UITextFieldViewModeWhileEditing;
    //设置代理
    textField.delegate = self;
}

@end