自定义可显示年月的DatePicker

利用自定义picker构建一个只显示年月的DatePicker。
话不多说，直接上代码：

- (void)createPicker;
{
    //构造可选年的数组
    [self pickerView];
    [self configDateYearRange];
}

- (UIPickerView *)pickerView
{
    if (!_pickerView) {
        _pickerView = [UIPickerView new];
        _pickerView.delegate = (id<UIPickerViewDelegate>)self;
        _pickerView.dataSource = (id<UIPickerViewDataSource>) self;
        [self addSubview:_pickerView];
        _pickerView.frame = CGRectMake(0, BTNHEIGHT, kScreenWidth, DATEPICKERHEIGHT);
    }
    return _pickerView;
}

/**
 设置datePicker显示的年的取值区间(当前月份-1之后的年)
 */
- (void)configDateYearRange
{
    NSDate *max = self.maximumDate;
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM"];
    NSString *yearMaxStr = [[formatter stringFromDate:max] substringToIndex:4];
    NSInteger yearMax = [yearMaxStr integerValue];
    
    NSDate *min = self.minimunDate;
    NSString *yearMinStr = [[formatter stringFromDate:min] substringToIndex:4];
    NSInteger yearMin = [yearMinStr integerValue];
    
    
    NSMutableArray *ret = [NSMutableArray array];
    for (NSInteger i = yearMin; i <= yearMax; i ++) {
        [ret addObject:[NSString stringWithFormat:@"%@",@(i)]];
    }
    
    self.yearsArr = ret;
}


/**
 把日期字符串转化为picker的数据源
 
 @param dateString 日期字符串
 */
- (void)updateMonthSourceWithDateString:(NSString *)dateString
{
    NSString *yearStr = [dateString substringToIndex:4];
    NSString *monthStr = nil;
    
    
    NSDate *max = self.maximumDate;
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM"];
    NSString *yearMaxStr = [[formatter stringFromDate:max] substringToIndex:4];
    NSInteger yearMax = [yearMaxStr integerValue];
    
    BOOL isThisYear = [yearStr integerValue] == yearMax;
    
    if (isThisYear) {
        
        NSDate *max = self.maximumDate;
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setDateFormat:@"yyyy-MM"];
        monthStr = [[formatter stringFromDate:max] substringFromIndex:5];
        
        
    }else {
        monthStr = @"12";
    }
    
    NSMutableArray *months = [NSMutableArray array];
    NSInteger month = [monthStr integerValue];
    for (NSInteger i = 1; i <= month ; i ++) {
        [months addObject:[NSString stringWithFormat:@"%@",@(i)]];
    }
    
    self.monthsArr = months;
}


/**
 切换年之后要更新月的显示
 */
- (void)updateMonthArr
{
    NSMutableArray *months = [NSMutableArray array];
    if ([self.pickerView selectedRowInComponent:0] == self.yearsArr.count-1) {
        NSDate *max = self.maximumDate;
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setDateFormat:@"yyyy-MM"];
        NSString *monthStr = [[formatter stringFromDate:max] substringFromIndex:5];
        
        NSInteger month = [monthStr integerValue];
        for (NSInteger i = 1; i <= month ; i ++) {
            [months addObject:[NSString stringWithFormat:@"%@",@(i)]];
        }
        self.monthsArr = months;
        
    }else {
        for (NSInteger i = 1; i <= 12 ; i ++) {
            [months addObject:[NSString stringWithFormat:@"%@",@(i)]];
        }
        self.monthsArr = months;
    }
}

#pragma mark - datasource
// returns the number of 'columns' to display.
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView;
{
    return 2;
}
// returns the # of rows in each component..
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component;
{
    if (component == 0) {
        return self.yearsArr.count;
    }else if (component == 1) {
        return self.monthsArr.count;
    }
    return 0;
}
#pragma mark delegate

// returns width of column and height of row for each component.
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component __TVOS_PROHIBITED;
{
    return kScreenWidth/2.f;
}

- (nullable NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component __TVOS_PROHIBITED;
{
    if (component == 0) {
        return [NSString stringWithFormat:@"%@年",self.yearsArr[row]];;
    }else if (component == 1) {
        return [NSString stringWithFormat:@"%@月",self.monthsArr[row]];;
    }
    return @"";
}

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component __TVOS_PROHIBITED;
{
    if (component == 0) {
        [self updateMonthArr];
        [pickerView reloadComponent:1];
    }
}

使用方法也超级简单：

WJDatePicker *pickerView = [[WJDatePicker alloc] initWithType:DatePickerType_YYYYMM];
    self.pickerView = pickerView;
    
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM"];
    
    pickerView.minimunDate = [formatter dateFromString:@"2000-01"];
    pickerView.maximumDate = [formatter dateFromString:@"2018-05"];
    pickerView.timeStr = @"2015-07";
    pickerView.clickReturn = ^(NSInteger tag, NSString *timeStr) {
        if (0 == tag) { //  取消
            NSLog(@"cancel");
        } else { //  确认
            
            NSLog(@"%@",timeStr);
        }
    };
    [self.view addSubview:pickerView];

附上下载地址：https://github.com/zgsddzwj/WJDatePicker