iOS开发inputView和inputAccessoryView

1、简介

　　起初看到这两个属性是在UIResponder中，只是可读的：

@property (nullable, nonatomic, readonly, strong) __kindof UIView *inputView NS_AVAILABLE_IOS(3_2);
@property (nullable, nonatomic, readonly, strong) __kindof UIView *inputAccessoryView NS_AVAILABLE_IOS(3_2);

　　后来在UITextField和UITextView中也有，是可读可写的：

@property (nullable, readwrite, strong) UIView *inputView;             
@property (nullable, readwrite, strong) UIView *inputAccessoryView;

　　用一张输入法的图片简单说明一下这两个属性：

　　inputAccessoryView：附件视图，就是上面汉子和拼音

　　inputView：就是下面的按键输入法

　　最上面的输入框：之前作法——监听键盘的通知，获取键盘高度处理输入框位置；

　　　　　　　　　　现在——是否可以把输入框放入到附件视图inputAccessoryView？只是一种想法，后期我会自己试试 勿喷！

2、自定义inputAccessoryView和inputView

　　2.1、直接赋值UITextField的这两个属性

    UIToolbar *toolBar = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 0, 90)];
    UIBarButtonItem *right = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(endEdi:)];
    UIBarButtonItem *right2 = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(endEdi:)];
    toolBar.items = [NSArray arrayWithObjects:right,right2,right,right,right,right,right, nil];
    self.inputTextField.inputAccessoryView = toolBar;
    UIView *inputView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 320)];
    UIImageView *igView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 180)];
    igView.image = [UIImage imageNamed:@"pic2.png"];
    [inputView addSubview:igView];
    inputView.backgroundColor = [UIColor greenColor];
    self.inputTextField.inputView =inputView;

• 设置坐标时只有高度才能起到约束，x、y、weight设置也不会有作用；
• 整个弹出视图的高度是inputView.height+inputAccessoryView.height，而且附件视图会紧贴inputView视图上面；
• inputView和inputAccessoryView的子视图需要有详细坐标约束；
• UIToolbar继承UIView，常用于附件视图上，作点击事件处理；

　　2.2、自定义控件的这两个属性

　　　　往往会用这两个属性来自定义键盘，其实可以自定义许多底部的弹出框！

　　　　由于UIResponder有这两个属性，所有大多数视图可以重写这个两个属性，以UILabel为例：

@interface MenuLabel()<UIPickerViewDelegate,UIPickerViewDataSource>
{
    UIToolbar *_inputAccessoryView;
    UIPickerView    *_inputView;
}
@end
@implementation MenuLabel

- (instancetype)initWithFrame:(CGRect)frame{
    if (self = [super initWithFrame:frame]) {
        [self setUI];
    }
    return self;
}
- (void)awakeFromNib{
    [super awakeFromNib];
    self.multipleTouchEnabled = YES;
    [self setUI];
}
- (void)setUI{
    self.userInteractionEnabled = YES;
    UITapGestureRecognizer *tap =[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGes:)];
    [self addGestureRecognizer:tap];
}

- (void)tapGes:(UITapGestureRecognizer *)ges{
    [self becomeFirstResponder];
}
-(UIView *)inputAccessoryView{
    if(!_inputAccessoryView)
    {
        UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 100)];
        view.backgroundColor = [UIColor grayColor];

        UIToolbar *toolBar = [[UIToolbar alloc]init];
        toolBar.frame = CGRectMake(0, 0, 100, 44);
        UIBarButtonItem *right = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(dodo)];
        toolBar.items = [NSArray arrayWithObject:right];
        
        [view addSubview:toolBar];
        return view;
    }
    return _inputAccessoryView;
}
-(UIPickerView *)inputView{
    if(!_inputView)
    {
        UIPickerView *  pickView = [[UIPickerView alloc]init];
        pickView.delegate =self;
        pickView.dataSource = self;
        pickView.showsSelectionIndicator = YES;
        return pickView;
    }
    return _inputView;
}
-(void)dodo{
    [self resignFirstResponder];
}
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
    return 1;
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
    return [NSString stringWithFormat:@"%ld",row];
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
    return 5;
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
    self.text =[NSString stringWithFormat:@"%ld",row];
}

- (BOOL)canBecomeFirstResponder{
    return YES;
}
@end

• 要设置  self.userInteractionEnabled = YES;重写- (BOOL)canBecomeFirstResponder{     return YES; } 方法；
• 这种方法附件的高度可以修改，但是底部并不会随inputView高度改变而变化，是固定的；
• inputView不设置坐标，会自适应展示，由于系统inputView高度固定，也不知道不同版本会不会变化，所以就不设置自定义视图inputView的高度 过高会覆盖附件，过低会覆盖不全；
• 附件的子视图需要详细坐标约束；