iOS开发inputView和inputAccessoryView

在UITextField和UITextField中能查到这两个属性

@property (readwrite, retain) UIView *inputView;

@property (readwrite, retain) UIView *inputAccessoryView;

在UITextField或者UITextField成为默认响应的时候，会弹出系统键盘。如果对这两个控件的inputView属性设置了自定义的view，在其成为第一响应的时候系统键盘将不再弹出，取而代之的是赋值给inputView的那个view。inputAccessoryView是键盘的辅助视图，即键盘上面那部分。同样当对inputAccessoryView设置了自定义view时，键盘弹出的同时，该view会作为辅助视图出现在键盘的上面，和键盘一起弹出。通常会使用pickerView作为自定义的弹出视图，这里为了简单起见，用一个普通的view演示：

基础代码演示

#import "ViewController.h"
#define SCREEN_BOUNDS [UIScreen mainScreen].bounds@interface ViewController ()@property (nonatomic, strong) UITextField *textField;
@property (nonatomic, strong) UIView *customInputView;
@property (nonatomic, strong) UIToolbar *customAccessoryView;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];[self loadBaseUI];
}- (void)loadBaseUI{[self.view addSubview:self.textField];
}- (UITextField *)textField{if (!_textField) {_textField = [[UITextField alloc]initWithFrame:CGRectMake(50, 100, SCREEN_BOUNDS.size.width - 100, 30)];_textField.layer.borderWidth = 1.0;_textField.layer.borderColor = [UIColor lightGrayColor].CGColor;_textField.layer.cornerRadius = 4.0;_textField.placeholder = @"测试";_textField.inputView = self.customInputView;_textField.inputAccessoryView = self.customAccessoryView;}return _textField;
}- (UIView *)customInputView{if (!_customInputView) {_customInputView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, SCREEN_BOUNDS.size.width, 220)];_customInputView.backgroundColor = [UIColor lightGrayColor];UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, 100, SCREEN_BOUNDS.size.width, 40)];label.textAlignment = NSTextAlignmentCenter;label.text = @"自定义inputView";[_customInputView addSubview:label];}return _customInputView;
}- (UIToolbar *)customAccessoryView{if (!_customAccessoryView) {_customAccessoryView = [[UIToolbar alloc]initWithFrame:(CGRect){0,0,SCREEN_BOUNDS.size.width,40}];_customAccessoryView.barTintColor = [UIColor orangeColor];UIBarButtonItem *space = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];UIBarButtonItem *finish = [[UIBarButtonItem alloc]initWithTitle:@"完成" style:UIBarButtonItemStyleDone target:self action:@selector(done)];[_customAccessoryView setItems:@[space,space,finish]];}return _customAccessoryView;
}- (void)done{[self.textField resignFirstResponder];
}@end

点击textField后的显示效果

对其他控件设置inputView和inputAccessoryView

除了UITextField和UITextField，有事我们可能想让别的控件实现类似效果，比如点击一个按钮、选中某个cell的时候弹出键盘，但是对于UITextField和UITextField以外的控件，inputView和inputAccessoryView是只读的

@property (nonatomic, readonly, retain) UIView *inputView

@property (nonatomic, readonly, retain) UIView *inputAccessoryView

因此如果要使用控件这两个属性，就要创建该控件的子视图，然后重新申明inputView和inputAccessoryView为readwrite的，并重写它们的get方法，这样在UITableViewCell成为第一响应的时候会自动弹出inputView和inputAccessoryView。以UITableView演示：

代码示例

//MyTableViewCell.h#import <UIKit/UIKit.h>
#define SCREEN_BOUNDS [UIScreen mainScreen].bounds@interface MyTableViewCell : UITableViewCell//属性申明为可读写
@property (nonatomic, strong, readwrite) UIView *inputView;@property (nonatomic, strong, readwrite) UIToolbar *inputAccessoryView;@end
//  MyTableViewCell.m#import "MyTableViewCell.h"@implementation MyTableViewCell//重写get方法
- (UIView *)inputView{if (!_inputView) {_inputView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, SCREEN_BOUNDS.size.width, 220)];_inputView.backgroundColor = [UIColor lightGrayColor];UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, 100, SCREEN_BOUNDS.size.width, 40)];label.textAlignment = NSTextAlignmentCenter;label.text = @"自定义inputView";[_inputView addSubview:label];}return _inputView;
}- (UIToolbar *)inputAccessoryView{if (!_inputAccessoryView) {_inputAccessoryView = [[UIToolbar alloc]initWithFrame:(CGRect){0,0,SCREEN_BOUNDS.size.width,40}];_inputAccessoryView.barTintColor = [UIColor orangeColor];UIBarButtonItem *space = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];UIBarButtonItem *finish = [[UIBarButtonItem alloc]initWithTitle:@"完成" style:UIBarButtonItemStyleDone target:self action:@selector(done)];[_inputAccessoryView setItems:@[space,space,finish]];}return _inputAccessoryView;
}- (void)done{[self resignFirstResponder];
}@end

在主视图控制器中创建一个tableView发现这样之后点击cell发现不会弹出inputView，最后查阅官方文档发现需要在子类中重写canBecomeFirstResponder方法：

在子类.m文件中添加

- (BOOL)canBecomeFirstResponder{return YES;
}

发现还是不行，最后手动becomeFirstResponder，终于实现了。PS原来选中都还不算是成为第一响应，坑爹啊！

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{MyTableViewCell *cell = (MyTableViewCell *)[tableView cellForRowAtIndexPath:indexPath];[cell becomeFirstResponder];
}

效果图

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