iPhone中的NSData對象

Question

NSString *imagePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/InAppLibrary"]; 

NSString *str=[@"/" stringByAppendingFormat:appDelegate_iPad.DrawPicture]; 
NSString *currentImageName=[imagePath stringByAppendingFormat:str]; 

NSData *dataImage = [NSData dataWithContentsOfFile:currentImageName]; 

這裏NSData對象的dataImage爲我提供了空值，任何好友幫我關於這裏的錯誤。

感謝

Answer 1

我覺得你的道路是錯誤的，你應該使用：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *docPath = [paths objectAtIndex:0]; 

    NSString *imagePath = [docPath stringByAppendingFormat:@"/InAppLibrary/%@", appDelegate_iPad.DrawPicture]; 
    NSData *dataImage = [NSData dataWithContentsOfFile: imagePath ];