UIPickerView实现年月选择器

刚做到一个UITextField弹出时间选择器选择年月的功能，UIDatePickerView并没有只选年月的，那就用UIPickerView自定义一个年月选择器，代码如下：

遵循UIPickerViewDelegate,UIPickerViewDataSource这两个代理先

UIView *limitDateView;
UIPickerView *limitPickerView;
NSString *thisYear;
NSString *thisMonth;

拿到当天的年月

NSDateFormatter *formmater = [[NSDateFormatter alloc] init];
    [formmater setDateFormat:@"yyyy-MM-dd"];
    
    DLog(@"%@",[formmater stringFromDate:[NSDate date]]);
    
    thisYear = [[formmater stringFromDate:[NSDate date]] componentsSeparatedByString:@"-"][0];
    thisMonth = [[formmater stringFromDate:[NSDate date]] componentsSeparatedByString:@"-"][1];
 
  
 
  
 
  
 
  
在选择的这个UITextFiled代理里面响应picker弹出
-(BOOL)textFieldShouldBeginEditing:(UITextField*)textField{
    if (textField.tag == 100) {
        [self setUpLimitView];
        [textField resignFirstResponder];
        return NO;
    }else
    {
        return YES;
    }
}

pickerview的代理方法是关键自定义显示部分
- (void)setUpLimitView{
    [limitDateView removeFromSuperview];
    limitDateView = [[UIView alloc] initWithFrame:CGRectMake(0, SCREENHEIGHT-192 - 64, SCREENWIDTH, 192)];
    limitDateView.backgroundColor = [UIColor groupTableViewBackgroundColor];
    limitPickerView = [[UIPickerView alloc]initWithFrame:CGRectMake(0, 44, SCREENWIDTH, 162)];
    
    //通过年月确定picker第一次显示年月顺便textfiled填入
    [limitPickerView selectRow:0 inComponent:[thisMonth integerValue]>=10?[thisMonth integerValue]:[[thisMonth substringFromIndex:1] integerValue] animated:YES];
    
    [limitPickerView selectRow:1 inComponent:[thisYear integerValue] animated:YES];

    expiryDateT.text = [NSString stringWithFormat:@"%@/%@",thisMonth,[thisYear substringFromIndex:2]];
    
    limitPickerView.delegate = self;
    limitPickerView.dataSource = self;
    [limitDateView addSubview:limitPickerView];
    
    UIToolbar *toolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, SCREENWIDTH, 44)];
    toolbar.backgroundColor = [UIColor clearColor];
    UIBarButtonItem *cancelBtn = [[UIBarButtonItem alloc] initWithTitle:@"取消" style:UIBarButtonItemStylePlain target:self action:@selector(clickHideLimit)];
    UIBarButtonItem *space = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
    UIBarButtonItem *doneBtn = [[UIBarButtonItem alloc] initWithTitle:@"确定" style:UIBarButtonItemStylePlain target:self action:@selector(clickDoneLimit)];
    [toolbar setItems:@[cancelBtn, space, doneBtn]];
    [limitDateView addSubview:toolbar];
    CATransition *animation = [CATransition  animation];
    animation.delegate = self;
    animation.duration = 0.3;
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    animation.type = kCATransitionPush;
    animation.subtype = kCATransitionFromTop;
    [limitDateView setAlpha:1.0f];
    [limitDateView.layer addAnimation:animation forKey:@"LimitAnimation"];
    [self.view addSubview:limitDateView];
}
 
  
#pragma mark - UIPickerViewDelegate
//告知在UIPickerView中有多少个滚轮
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
    return 2;
    
}
//告知在UIPickerView中，每个滚轮显示多少行的值
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
    if (component == 0) {
        return 12;
    }else
    {
        return 100;
    }
}
//告知每个滚轮的每个行显示的内容是什么
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
    if (component==0) {
        return [NSString stringWithFormat:@"%ld月",row+1];
    }else
    {
        return [NSString stringWithFormat:@"%ld年",[thisYear intValue]+row];
    }
}

//当滚轮停止滚动时，会回调这个函数，告知你当前选择了哪个滚轮的哪个值
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
    NSLog(@"%ld月,%ld年",(long)[pickerView selectedRowInComponent:0]+1,(long)[pickerView selectedRowInComponent:1]+[thisYear integerValue]);
    NSString *monthStr = [pickerView selectedRowInComponent:0]+1<10?[NSString stringWithFormat:@"0%ld",(long)[pickerView selectedRowInComponent:0]+1]:[NSString stringWithFormat:@"%ld",(long)[pickerView selectedRowInComponent:0]+1];
    
    NSString *yearStr = [[NSString stringWithFormat:@"%ld",(long)[pickerView selectedRowInComponent:1]+[thisYear integerValue]] substringFromIndex:2];
    
    expiryDateT.text = [NSString stringWithFormat:@"%@/%@",monthStr,yearStr];
}

#pragma mark - toolbar事件
- (void)clickHideLimit {
    [limitDateView removeFromSuperview];
    expiryDateT.text = @"";
}
- (void)clickDoneLimit {
    [limitDateView removeFromSuperview];
}