進度條相關的操作都定義在

ASIProgressDelegate .h 檔案中。

而且所有的方法都是optional的。

ipone上更新進度條的方法 ：- (void)setProgress:(float)newProgress;

#if TARGET_OS_IPHONE
- (void)setProgress:(float)newProgress;
#else
- (void)setDoubleValue:(double)newProgress;
- (void)setMaxValue:(double)newMax;
#endif

並且這個方法 直接是 @interface UIProgressView : UIView <NSCoding> 類中實現的。所有可以直接把UIProgressView 的例項賦值給ASIHTTPRequest下面的兩個屬性，而無需實現 ASIProgressDelegate 協議。

// Delegate for displaying upload progress (usually an NSProgressIndicator, but you can supply a different object and handle this yourself)
 id <ASIProgressDelegate> uploadProgressDelegate;
 
 // Delegate for displaying download progress (usually an NSProgressIndicator, but you can supply a different object and handle this yourself)
 id <ASIProgressDelegate> downloadProgressDelegate;

更新進度條的方法

// Updates upload progress (notifies the queue and/or uploadProgressDelegate of this request)
- (void)updateUploadProgress;

// Updates download progress (notifies the queue and/or uploadProgressDelegate of this request)
- (void)updateDownloadProgress;