iOS國家城市選擇器 讀取本地json檔案

最近在做的産品有這麼個需求，讀取本地json檔案中的國家和城市資訊，顯示到pickerview上，在網上查了一下，發現沒有什麼合适的可用資源，是以就自己寫了一個簡單的DEMO。

效果圖：

讀取本地json的方法如下：

+ (NSMutableArray *)getCityData
{
    NSArray *jsonArray = [[NSArray alloc]init];
    NSData *fileData = [[NSData alloc]init];
    NSUserDefaults *UD = [NSUserDefaults standardUserDefaults];
    if ([UD objectForKey:@"city"] == nil) {
        NSString *path;
        path = [[NSBundle mainBundle] pathForResource:@"zh_CN" ofType:@"json"];
        fileData = [NSData dataWithContentsOfFile:path];
        
        [UD setObject:fileData forKey:@"city"];
        [UD synchronize];
    }
    else {
        fileData = [UD objectForKey:@"city"];
    }
    NSMutableArray *array = [[NSMutableArray alloc]initWithCapacity:0];
    jsonArray = [NSJSONSerialization JSONObjectWithData:fileData options:NSJSONReadingMutableLeaves error:nil];
    for (NSDictionary *dict in jsonArray) {
        [array addObject:dict];
    }
    
    return array;
}
           

citypicker主要代碼如下：

//傳回顯示的列數
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    if (pickerView == self.cityPicker) {
        return 3;
    }
    else
        return 1;
}

//傳回目前列顯示的行數
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
    
    if (component == 0) {
        return [YMUtils getCityData].count;
    }
    else if (component == 1) {
        NSArray *array = [YMUtils getCityData][row1][@"children"];
        if ((NSNull*)array != [NSNull null]) {
            return array.count;
        }
        return 0;
    }
    else {
        NSArray *array = [YMUtils getCityData][row1][@"children"];
        if ((NSNull*)array != [NSNull null]) {
            NSArray *array1 = [YMUtils getCityData][row1][@"children"][row2][@"children"];
            if ((NSNull*)array1 != [NSNull null]) {
                return array1.count;
            }
            return 0;
        }
        return 0;
    }
}
//設定目前行的内容
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
    
    if(component == 0) {
        return [YMUtils getCityData][row][@"name"];
    }
    else if (component == 1) {
        return [YMUtils getCityData][row1][@"children"][row][@"name"];
    }
    else if (component == 3) {
        return [YMUtils getCityData][row1][@"children"][row2][@"children"][row][@"name"];
    }
    return nil;
    
}
//選擇的行數
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
    if (component == 0) {
        row1 = row;
        row2 = 0;
        row3 = 0;
        [self.cityPicker reloadComponent:1];
        [self.cityPicker reloadComponent:2];
        
    }
    else if (component == 1){
        row2 = row;
        row3 = 0;
        [self.cityPicker reloadComponent:2];
        
    }
    else {
        row3 = row;
    }
    NSInteger cityRow1 = [self.cityPicker selectedRowInComponent:0];
    NSInteger cityRow2 = [self.cityPicker selectedRowInComponent:1];
    NSInteger cityRow3 = [self.cityPicker selectedRowInComponent:2];
    NSMutableString *str = [[NSMutableString alloc]init];
    [str appendString:[YMUtils getCityData][cityRow1][@"name"]];
    NSArray *array = [YMUtils getCityData][cityRow1][@"children"];
    if ((NSNull*)array != [NSNull null]) {
        [str appendString:[YMUtils getCityData][cityRow1][@"children"][cityRow2][@"name"]];
        NSArray *array1 = [YMUtils getCityData][cityRow1][@"children"][cityRow2][@"children"];
        if ((NSNull*)array1 != [NSNull null]) {
            [str appendString:[YMUtils getCityData][cityRow1][@"children"][cityRow2][@"children"][cityRow3][@"name"]];
        }
    }
    self.cityLabel.text = str;
}
//每行顯示的文字樣式
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view

{
    
    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 107, 30)];
    titleLabel.textAlignment = NSTextAlignmentCenter;
    titleLabel.font = [UIFont systemFontOfSize:14];
    titleLabel.backgroundColor = [UIColor clearColor];
    if (component == 0) {
        titleLabel.text = [YMUtils getCityData][row][@"name"];
    }
    else if (component == 1) {
        titleLabel.text = [YMUtils getCityData][row1][@"children"][row][@"name"];
    }
    else {
        titleLabel.text = [YMUtils getCityData][row1][@"children"][row2][@"children"][row][@"name"];
    }
    return titleLabel;
    
}
           

DEMO的下載下傳位址：http://download.csdn.net/detail/u011918080/8200985