更新UIPickerView行數

Question

我有一個名爲sectionNamesArray的NSMutableArray填充的UIPickerView。當一個項目被添加到sectionNamesArray時，我如何手動獲取這個委託被調用？

-- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component 

{ 

return ([sectionNamesArray count] + 1); 

} 

問題是我把這個pickerView添加到titleView中navBar的中心。如果我嘗試刪除UIPickerView並重新分配它，以便再次調用委託，PickerView將顯示在導航欄的左側，而不是中心。我猜測也許界面生成器設置在中心......？

下面是該代碼：

-(void) setupPickerView{ 
myPickerView = nil; 
myPickerView = [[UIPickerView alloc] init]; 
myPickerView.backgroundColor = [UIColor clearColor]; 
myPickerView.delegate = self; 
myPickerView.dataSource = self; 
myPickerView.showsSelectionIndicator = YES; 
[self.navigationController.navigationBar setBackgroundView:myPickerView]; 

CGSize pickerSize = [myPickerView sizeThatFits:CGSizeZero]; 
UIView *pickerTransformView = [[UIView alloc] initWithFrame:CGRectMake(-40.0, -43.0, pickerSize.width, pickerSize.height)]; 
pickerTransformView.transform = CGAffineTransformMakeScale(.55f, .55f); 

[pickerTransformView addSubview:myPickerView]; 
[self.navigationController.navigationBar setBackgroundView:pickerTransformView]; 

} 

Answer 1

當你添加了一些你的陣列不能使用[UIPickerView reloadAllComponents]或- (void)reloadComponent:(NSInteger)component？

這很可能會查詢您的委託並調用檢查數組並重新加載視圖所需的所有內容。