UIToolbar自定義UIBarButtonItem

Question

在我的測試項目中，我計劃擁有多個選擇器視圖。對於這些選擇器視圖，將會有UIToolbars和自定義的UIBarButtons。我試圖創建一個類方法，這樣我就不必重複代碼，但它看起來像按鈕沒有顯示出來。

機械手完成Button.h

#import <UIKit/UIKit.h> 

@interface UIBarButtonItem (test) 
+ (UIBarButtonItem*)barButtonItemWithTint:(UIColor*)color andTitle:(NSString*)itemTitle andTarget:(id)theTarget andSelector:(SEL)selector; 
@end 

機械手完成Button.m

#import "PickerDoneButton.h" 

@implementation UIBarButtonItem (test) 
+ (UIBarButtonItem*)barButtonItemWithTint:(UIColor*)color andTitle:(NSString*)itemTitle andTarget:(id)theTarget andSelector:(SEL)selector 
{ 
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom]; 
    button.tintColor = color; 
    button.backgroundColor = [UIColor yellowColor]; 
    [button addTarget:theTarget action:selector forControlEvents:UIControlEventValueChanged]; 
    UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithCustomView:button]; 
    return doneButton; 
} 
@end 

而且在我查看Controller.m或者使用此類方法（我省略選擇器視圖方法後來viewDidLoad）

#import "ViewController.h" 
#import "PickerDoneButton.h" 

@interface ViewController() 
@property (strong, nonatomic) NSArray *numberofPeople; 
@property (strong, nonatomic) UIPickerView *countPeople; 
@end 

@implementation ViewController 
- (void)viewDidLoad { 
    [super viewDidLoad]; 
    self.countPeople = [[UIPickerView alloc] init]; 
    self.countPeople.dataSource = self; 
    self.countPeople.delegate = self; 
    self.numberofPeople = @[@"1",@"2",@"3"]; 

    UIToolbar *countPeopleToolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0,0,0,50)]; 
    countPeopleToolbar.barStyle = UIBarStyleBlackOpaque; 
    // Call the UIBarButtonItem from PickerDoneButton.h 
    countPeopleToolbar.items = @[[UIBarButtonItem barButtonItemWithTint:[UIColor redColor] andTitle:@"Done" andTarget:self andSelector:@selector(doneClicked)]]; 
    [self pickerView:self.countPeople didSelectRow:0 inComponent:0]; 
} 

我正確使用類方法嗎？

Answer 1

是的，你做的是正確的。只有你缺少的是你沒有將你的button的框架設置在doneButton之內。由於按鈕沒有任何框架設置，它不會顯示。創建按鈕後添加此項。

button.frame = CGRectMake(0, 0, 30, 30); // change frame as per your requirement