IOS-OC之進階元件PickerView之二

第一篇寫了簡單的拾取器的展示和擷取，這一篇是雙輪拾取器的展示和擷取，内容大緻差不多，主要是雙輪之間的關聯~~~

代碼：

.h的代碼

#import <UIKit/UIKit.h>

//<UIPickerViewDelegate, UIPickerViewDataSource>是事件代理，和資料源代理，在.m檔案中實作方法添加事件和資料源
@interface ViewController : UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>
//資料字典
@property (nonatomic, strong)  NSDictionary *data;
//拾取器第一個輪的資料數組
@property (nonatomic, strong) NSArray *pickerData1;
//拾取器第二個輪的資料數組
@property (nonatomic, strong) NSArray *pickerData2;
//拾取器聲明
@property (strong, nonatomic) IBOutlet UIPickerView *pv;
//顯示拾取器的标簽
@property (strong, nonatomic) IBOutlet UILabel *lable;
//點選按鈕顯示拾取器方法聲明
-(IBAction)onClick:(id)sender;
@end
           

.m檔案的代碼

//實作協定UIPickerViewDelegate方法
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
    if(component == ){
        return [self.pickerData1 objectAtIndex:row];

    }else{
        return [self.pickerData2 objectAtIndex:row];
    }
}

//選擇某一行時觸發的事件，拾取器第二個輪的資料是和第一個輪關聯的
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
    if(component == ){
        NSString *selectedCol1 = [self.pickerData1 objectAtIndex:row];
        NSArray *array = [self.data objectForKey:selectedCol1];
        self.pickerData2 = array;
        [self.pv reloadComponent:];
    }
}
//傳回兩個輪的資料數量
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
    if(component == ){
        return [self.pickerData1 count];
    }else{
        return [self.pickerData2 count];
    }
}
//傳回拾取器的輪數
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
    return ;
}
//點選按鈕顯示目前拾取器的資料
-(IBAction)onClick:(id)sender{
    //第一個輪的行數
    NSInteger row1 = [_pv selectedRowInComponent:];
    //第二個輪的行數
    NSInteger row2 = [_pv selectedRowInComponent:];
    //第一個輪的值
    NSString * mys1 = [self.pickerData1 objectAtIndex:row1];
    //第二個輪的值
    NSString *mys2 = [self.pickerData2 objectAtIndex:row2];
    NSString *str = @"";
    //标簽顯示兩個輪的拼接字元串
    _lable.text = [str stringByAppendingString:[NSString stringWithFormat:@"%@,%@",mys1,mys2]];

}

//初始化
- (void)viewDidLoad {
    [super viewDidLoad];

    //用NSBundle讀取資源檔案
    NSBundle *bundle = [NSBundle mainBundle];
    //statedictionary是資源檔案的名字
    NSString *plistPath = [bundle pathForResource:@"statedictionary" ofType:@"plist"];
    NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
    self.data = dict;

    NSArray *col1 = [self.data allKeys];
    //排序
    NSArray *sorted = [col1 sortedArrayUsingSelector:@selector(compare:)];
    self.pickerData1 = sorted;
    //初始化第二個輪的資料
    NSString *selectedCol1 = [self.pickerData1 objectAtIndex: ];
    NSArray *col2 = [self.data objectForKey:selectedCol1];
    self.pickerData2 = col2;
    // Do any additional setup after loading the view, typically from a nib.
}
           

資源plist檔案為：

nib檔案

遇到的問題：

中途我改過一次UIPickerView的名稱，然後報錯了，233~

找了半天，發現改了名稱之後要在nib檔案中重新拖拽，讓File’s Owner和新改的名稱連接配接起來~~~

每次都會遇到問題，解決問題的過程就是我們成長的過程，加油~~