如何使應用程序UISlider snappy？

Question

這是我當前如何做

- (IBAction)sliderDistanceChanged { 
    CGFloat sliderPosition = self.sliderDistance.value; 
    NSUInteger sliderIndex = [BGDistanceFilterStop indexForFilterEffect:sliderPosition]; 

    self.distanceFilterForCatalog = @([BGDistanceFilterStop numberValueOfDistance:sliderIndex]); 
    //self.distanceFilterForCatalog= @(self.sliderDistance.value).roundWithForDistanceFilter; 
    //[self.distanceFilter setTitle:self.distanceFilterForCatalog.distanceForm forState:UIControlStateNormal]; 
    [self.distanceFilter setTitle:[BGDistanceFilterStop stringValueOfDistance:sliderIndex] forState:UIControlStateNormal]; 

} 
- (IBAction)SliderNoLongerTouched:(id)sender { 
    CGFloat sliderIndex = [BGDistanceFilterStop sliderSnappedPosition:self.sliderDistance.value]; 
    self.sliderDistance.value=sliderIndex; 
} 

它基本上檢測self.sliderDistance.value然後根據舍入後設置的報告值。

一旦用戶不再聯繫，我改變self.sliderDistance.value

的立場，即是罰款。

但是，我想在用戶修改之前更改self.sliderDistance.value。但是，這與iOS用於跟蹤滑塊的雙手位置和值的變量是相同的。

那麼，如何安排按鈕捕捉到正確的位置而不改變self.sliderDistance.value？

Answer 1

(IBAction)sliderDistanceChanged { 
    CGFloat sliderPosition = self.sliderDistance.value; 
    NSUInteger sliderIndex = [BGDistanceFilterStop indexForFilterEffect:sliderPosition]; 

    self.distanceFilterForCatalog = @([BGDistanceFilterStop numberValueOfDistance:sliderIndex]); 
    //self.distanceFilterForCatalog= @(self.sliderDistance.value).roundWithForDistanceFilter; 
    //[self.distanceFilter setTitle:self.distanceFilterForCatalog.distanceForm forState:UIControlStateNormal]; 
    [self.distanceFilter setTitle:[BGDistanceFilterStop stringValueOfDistance:sliderIndex] forState:UIControlStateNormal]; 

} 
- (IBAction)SliderNoLongerTouched:(id)sender { 
    CGFloat sliderIndex = [BGDistanceFilterStop sliderSnappedPosition:self.sliderDistance.value]; 
    self.sliderDistance.value=sliderIndex; 
} 

基本上它檢測到self.sliderDistance.value，然後根據舍入後設置的報告值。

一旦用戶不再聯繫，我改變self.sliderDistance.value

這很好的位置。

何

Answer 2

我假設這些操作中的每一個都與有問題的UISlider相關聯。第一個由valueChanged觸發，第二個由touchUpInside觸發。

在這種情況下，首先改變你的簽名，這些

- (IBAction)sliderDistanceChanged:(UISlider*)sender; 
- (IBAction)sliderNoLongerTouched:(UISlider*)sender; 

，讓您可以參考滑蓋sender代替self.sliderDistance（更簡單，更自足）。

修改sliderDistanceChanged

- (IBAction)sliderDistanceChanged:(UISlider*)sender; 
      //allocate the raw slider value to a variable 
      CGFloat rawValue = sender.value; 

      //calculate the snapped value 
      CGFloat snappedValue = [BGDistanceFilterStop sliderSnappedPosition:sender.value]; 

      //snap the slider in position 
      sender.value = snappedValue; 


     //now do the rest of your processing 
     //using rawValue if you want the raw value, 
     //snappedValue if you want the snapped value 

     } 

簡化sliderNoLongerTouched

- (IBAction)sliderNoLongerTouched:(id)sender { 
    sender.value = [BGDistanceFilterStop sliderSnappedPosition:sender.value]; 
}   

（你實際上並不在sliderDistanceChanged需要這個現在，作爲價值卡扣到位）