iphone 保存图片以及读取图片 demo

 显示图片：思路：想利用fileManager将某一目录的文件夹中的图片名称保存在可变数组中，然后再利用循环，将图片保存到图片数组中，然后在显示出来。

显示图片

-(IBAction) showImage:( id)sender
{
    
    NSFileManager *fileManager = [NSFileManager defaultManager];  
    NSArray *files = [NSArray arrayWithArray:[fileManager URLsForDirectory:NSMusicDirectory inDomains:NSUserDomainMask ]];
    NSLog( @" files :%d ",[files    count]);
    NSLog( @" the files is %@ ",[files objectAtIndex: 0]);
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex: 0];
    BOOL isDir = NO;
    NSLog( @" %d ",[paths count]);
    
    NSError *error = nil;
    NSArray *fileList = [[NSArray alloc] init];
    NSMutableArray *filePath = [NSMutableArray arrayWithCapacity: 100 ];
    NSMutableArray *imgArray = [NSMutableArray arrayWithCapacity: 200];
     // NSArray *filePath = [[NSArray alloc] init];
    fileList = [fileManager contentsOfDirectoryAtPath:documentsDirectory error:&error];
     for (NSString *file  in fileList) {
        NSLog( @" fileName is :%@ ",file);
        [filePath addObject:[documentsDirectory stringByAppendingPathComponent:file]];
        
    }
     
      for ( int i =  0; i<[fileList count]; i++)
     {
         NSString *filePathName = [filePath objectAtIndex:i];
          if ([filePathName hasSuffix: @" png "]) {
             UIImage *temp = [UIImage imageWithContentsOfFile:filePathName];
             [imgArray addObject:temp];
         }
     } 
    
    [imgView1 setImage:[imgArray objectAtIndex: 0]];
    [imgView2 setImage:[imgArray objectAtIndex: 1]];
    [imgView3 setImage:[imgArray objectAtIndex: 2]];
    [imgView4 setImage:[imgArray objectAtIndex: 3]];
    [imgView5 setImage:[imgArray objectAtIndex: 4]];
    [imgView6 setImage:[imgArray objectAtIndex: 5]];
    [imgView7 setImage:[imgArray objectAtIndex: 6]];
    [imgView8 setImage:[imgArray objectAtIndex: 7]];
    [imgView9 setImage:[imgArray objectAtIndex: 8]];
    NSURL *url = [NSURL URLWithString: @" http://list.image.baidu.com/t/image_category/galleryimg/menstar/hk/luo_zhi_xiang.jpg "];  
    NSData *data = [NSData dataWithContentsOfURL:url];  
    UIImage *img = [UIImage imageWithData:data]; 
    
    NSLog( @" width:%f,heigh:%f ",img.size.width,img.size.height);
     /* 测试NSHomeDirectory
    NSString *homeDirectionary = [NSHomeDirectory() stringByAppendingPathComponent:@"a"];
    NSLog(@"路径:%@",homeDirectionary); */
    
     /*  创建文件夹  */
    NSString *newPath = [documentsDirectory stringByAppendingPathComponent: @" test "];

    BOOL isOK = [fileManager createDirectoryAtPath:newPath attributes:nil];
    NSString *imagePath = [documentsDirectory stringByAppendingPathComponent: @" nodeOff.png "];
    NSLog( @" imagePath:%@ ",imagePath);
    NSData *imageData = [NSData dataWithContentsOfFile:imagePath];
    NSString *newPathCopy = [NSString stringWithFormat: @" %@/nodeOff.png ",newPath];
    NSLog( @" newPathCopy;%@ ",newPathCopy);
    
    BOOL isSave = [fileManager createFileAtPath:newPathCopy contents:imageData attributes:nil];    
    NSLog( @" isSave:%@ ",isSave ?  @" YES ": @" NO ");
    [imgUrl setImage:img];
    

 

  

 

 保存图片：思路，先将图片保存为NSdata，在保存到文件夹中

保存图片

- ( void)viewDidLoad {
    [super viewDidLoad];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex: 0];
    NSString *savedImagePath1 = [documentsDirectory stringByAppendingPathComponent: @" left.png "];
    NSString *savedImagePath2 = [documentsDirectory stringByAppendingPathComponent: @" right.png "];
    NSString *savedImagePath3 = [documentsDirectory stringByAppendingPathComponent: @" right3.png "];
    NSString *savedImagePath4 = [documentsDirectory stringByAppendingPathComponent: @" up3.png "];
    NSString *savedImagePath5 = [documentsDirectory stringByAppendingPathComponent: @" nodeOff.png "];
    NSString *savedImagePath6 = [documentsDirectory stringByAppendingPathComponent: @" nodeOn.png "];
    NSString *savedImagePath7 = [documentsDirectory stringByAppendingPathComponent: @" webcam002.png "];
    NSString *savedImagePath8 = [documentsDirectory stringByAppendingPathComponent: @" webcam003.png "];
    NSString *savedImagePath9 = [documentsDirectory stringByAppendingPathComponent: @" plus3.png "];
    
     // also be .jpg or another
     UIImage *newImage1 = [UIImage imageNamed: @" left.png "];
    UIImage *newImage2 = [UIImage imageNamed: @" right.png "];
    UIImage *newImage3 = [UIImage imageNamed: @" right3.png "];
    UIImage *newImage4 = [UIImage imageNamed: @" up3.png "];
    UIImage *newImage5 = [UIImage imageNamed: @" nodeOff.png "];
    UIImage *newImage6 = [UIImage imageNamed: @" nodeOn.png "];
    UIImage *newImage7 = [UIImage imageNamed: @" webcam002.png "];
    UIImage *newImage8 = [UIImage imageNamed: @" webcam003.png "];
    UIImage *newImage9 = [UIImage imageNamed: @" plus3.png "];
    
    NSData *imageData1 = UIImagePNGRepresentation(newImage1);
    NSData *imageData2 = UIImagePNGRepresentation(newImage2);
    NSData *imageData3 = UIImagePNGRepresentation(newImage3);
    NSData *imageData4 = UIImagePNGRepresentation(newImage4);
    NSData *imageData5 = UIImagePNGRepresentation(newImage5);
    NSData *imageData6 = UIImagePNGRepresentation(newImage6);
    NSData *imageData7 = UIImagePNGRepresentation(newImage7);
    NSData *imageData8 = UIImagePNGRepresentation(newImage8);
    NSData *imageData9 = UIImagePNGRepresentation(newImage9);
    
     // UIImageJPEGRepresentation(image)
    [imageData1 writeToFile:savedImagePath1 atomically:YES];
    [imageData2 writeToFile:savedImagePath2 atomically:YES];
    [imageData3 writeToFile:savedImagePath3 atomically:YES];
    [imageData4 writeToFile:savedImagePath4 atomically:YES];
    [imageData5 writeToFile:savedImagePath5 atomically:YES];
    [imageData6 writeToFile:savedImagePath6 atomically:YES];
    [imageData7 writeToFile:savedImagePath7 atomically:YES];
    [imageData8 writeToFile:savedImagePath8 atomically:YES];
    [imageData9 writeToFile:savedImagePath9 atomically:YES];

    

 

 

1：保存图片以及读取图片的saveImage