我是电话编程的新手。我将图像存储在数组中然后使用下面的代码我在缩略图中显示图像它的工作速度非常快。如果同样认为我已经将图像存储在数据库中并检索图像并存储在数组中然后使用下面的代码我正在缩略图中显示图像，显示缩略图图像需要很长时间。
arrayz = [NSMutableArray arrayWithObjects:[UIImage imageNamed:@"image3.jpg"],
[UIImage imageNamed:@"image4.jpg"],
[UIImage imageNamed:@"image5.jpg"],
[UIImage imageNamed:@"image3.jpg"],
[UIImage imageNamed:@"image5.jpg"],
[UIImage imageNamed:@"image4.jpg"],
[UIImage imageNamed:@"image2.jpg"],
[UIImage imageNamed:@"image3.jpg"],
[UIImage imageNamed:@"image2.jpg"],
[UIImage imageNamed:@"image5.jpg"],
nil];
NSLog(@"%i" , [arrayz count]);
NSLog(@"%@",arrayz);
myScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0.0, 0.0, 320.0, 840.0)];
myScrollView.delegate = self;
myScrollView.contentSize = CGSizeMake(320.0, 840.0);
myScrollView.backgroundColor = [UIColor whiteColor];
[self.view addSubview:myScrollView];
float horizontal = 8.0;
float vertical = 8.0;
for(int i=0; i<[arrayz count]; i++)
{
if((i%4) == 0 && i!=0)
{
horizontal = 8.0;
vertical = vertical + 70.0 + 8.0;
}
buttonImage1 = [UIButton buttonWithType:UIButtonTypeCustom];
[buttonImage1 setFrame:CGRectMake(horizontal, vertical, 70.0, 70.0)];
[buttonImage1 setTag:i];
[buttonImage1 setImage:[arrayz objectAtIndex:i] forState:UIControlStateNormal];
[buttonImage1 addTarget:self action:@selector(buttonImagePressed:) forControlEvents:UIControlEventTouchUpInside];
[buttonImage1 setImage:[UIImage imageNamed:@"Overlay.png"] forState:UIControlStateSelected];
buttonImage = [UIButton buttonWithType:UIButtonTypeCustom];
[buttonImage setFrame:CGRectMake(horizontal, vertical, 70.0, 70.0)];
[buttonImage setTag:i];
[buttonImage setImage:[arrayz objectAtIndex:i] forState:UIControlStateNormal];
[buttonImage addTarget:self action:@selector(buttonImagePressed:) forControlEvents:UIControlEventTouchUpInside];
[buttonImage setImage:[UIImage imageNamed:@"Overlay.png"] forState:UIControlStateSelected];
// UIImageView *imageee=[[UIImageView alloc]initWithFrame:CGRectMake(10,10, 80,80)];
// [buttonImage setImage:[UIImage imageNamed:@"check.jpg"]];
// [buttonImage setImage:imageee forState:UIControlStateSelected];
// [buttonImage setImage:button.currentImage forState:UIControlStateNormal];
[myScrollView addSubview:buttonImage1];
[myScrollView addSubview:buttonImage];
horizontal = horizontal + 70.0 + 8.0;
[myScrollView setContentSize:CGSizeMake(320.0, vertical + 78.0)];
}
// Do any additional setup after loading the view, typically from a nib.
self.navigationItem.leftBarButtonItem = self.editButtonItem;
// UIBarButtonItem *done =[[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonItemStyleDone target:self action:nil];
UIBarButtonItem *done = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(insertNewObject:)];
self.navigationItem.rightBarButtonItem = done;
下面的代码使用数据库我将图像存储在数组中，然后我在缩略图中显示图像。在缩略图中显示图像需要很长时间。
NSString *docsDir;
NSArray *dirPaths;
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = [dirPaths objectAtIndex:0];
array=[[NSMutableArray alloc]init];
array1=[[NSMutableArray alloc]init];
// array2=[[NSMutableArray alloc]init];
// Build the path to the database file
databasePath = [docsDir stringByAppendingPathComponent: @"Taukydataaa.db"];
// NSLog(@"%@",databasePath);
NSFileManager *fn=[NSFileManager defaultManager];
NSError *error;
BOOL success=[fn fileExistsAtPath:databasePath];
if(!success) {
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"Taukydataaa.db"];
success = [fn copyItemAtPath:defaultDBPath toPath:databasePath error:&error];
}
const char *dbpath = [databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat: @"select * from path "];
const char *query_stmt = [querySQL UTF8String];
if (sqlite3_prepare_v2(contactDB, query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
while(sqlite3_step(statement) == SQLITE_ROW)
{
NSString* email_idField = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement,1)];
// NSLog(@"%@",email_idField);
NSString* email_idField1 = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement,0)];
// NSLog(@"%@",email_idField1);
// NSString *email_idField2 = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement,2)];
NSLog(@"ASlma");
NSLog(@"%@",email_idField1);
[array addObject:email_idField];
[array1 addObject:email_idField1];
NSLog(@"%@",array);
NSLog(@"%@",array1);
// [array1 addObject:email_idField1];
// [array2 addObject:email_idField2];
}
sqlite3_finalize(statement);
}
sqlite3_close(contactDB);
}
blaukypath =[[NSMutableArray alloc]init];
for (NSString* path in array)
{
[blaukypath addObject:[UIImage imageWithContentsOfFile:path]];
NSLog(@"%@",path);
}
NSLog(@"%@",blaukypath1);
myScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0.0, 0.0, 320.0, 840.0)];
myScrollView.delegate = self;
myScrollView.contentSize = CGSizeMake(320.0, 840.0);
myScrollView.backgroundColor = [UIColor whiteColor];
[self.view addSubview:myScrollView];
float horizontal = 8.0;
float vertical = 8.0;
for(int i=0; i<[blaukypath count]; i++)
{
if((i%4) == 0 && i!=0)
{
horizontal = 8.0;
vertical = vertical + 70.0 + 8.0;
}
buttonImage1 = [UIButton buttonWithType:UIButtonTypeCustom];
[buttonImage1 setFrame:CGRectMake(horizontal, vertical, 70.0, 70.0)];
[buttonImage1 setTag:i];
[buttonImage1 setImage:[blaukypath objectAtIndex:i] forState:UIControlStateNormal];
[buttonImage1 addTarget:self action:@selector(buttonImagePressed:) forControlEvents:UIControlEventTouchUpInside];
[buttonImage1 setImage:[UIImage imageNamed:@"Overlay.png"] forState:UIControlStateSelected];
buttonImage = [UIButton buttonWithType:UIButtonTypeCustom];
[buttonImage setFrame:CGRectMake(horizontal, vertical, 70.0, 70.0)];
[buttonImage setTag:i];
[buttonImage setImage:[blaukypath objectAtIndex:i] forState:UIControlStateNormal];
[buttonImage addTarget:self action:@selector(buttonImagePressed:) forControlEvents:UIControlEventTouchUpInside];
[buttonImage setImage:[UIImage imageNamed:@"Overlay.png"] forState:UIControlStateSelected];
// UIImageView *imageee=[[UIImageView alloc]initWithFrame:CGRectMake(10,10, 80,80)];
// [buttonImage setImage:[UIImage imageNamed:@"check.jpg"]];
// [buttonImage setImage:imageee forState:UIControlStateSelected];
// [buttonImage setImage:button.currentImage forState:UIControlStateNormal];
[myScrollView addSubview:buttonImage1];
[myScrollView addSubview:buttonImage];
horizontal = horizontal + 70.0 + 8.0;
[myScrollView setContentSize:CGSizeMake(320.0, vertical + 78.0)];
}
我认为问题不在于数据库。主要的想法是，如果我从手机真实设备上拍摄图像，图像在缩略图中显示的时间太长。如果我拍摄一些图像并存储在数组中，在缩略图中显示的图像工作得非常快。 . 任何人都可以告诉我如何解决这个问题。谢谢阿斯拉姆