图片由 UIImagePickerControllerSourceTypeCamera 拍摄 如何将其保存在 ios 的数据库中
image was taken by UIImagePickerControllerSourceTypeCamera how to save it in database in ios
编码为 .m
-(IBAction) getPhoto:(id) sender {
picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
} else {
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
UIAlertView *noCameraAlert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"You don't have a camera for this device" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
//shows above alert if there's no camera
[noCameraAlert show];
}else{
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
picker.allowsEditing = YES;
picker.delegate = self;
}
}
[self presentViewController:picker animated:YES completion:nil];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
UIImage *img = [info objectForKey:UIImagePickerControllerOriginalImage];
img = [info valueForKey:UIImagePickerControllerEditedImage];
self.imageView.image = img;
imagData = UIImagePNGRepresentation(img);
[picker dismissViewControllerAnimated:YES completion:nil];
}
图像现在已放置在图像视图中,我如何将图像保存在数据库中
我已经有了可以插入数据的数据库
要插入:
NSMutableArray *listItemsarr = [[NSMutableArray alloc] init];
if([listItemsarr count]==0){
NSString *insertQry=@"INSERT INTO selection_tbl (expenses_value,category,date,payment,description) VALUES(?,?,?,?,?)";
sqlite3_stmt *stmt=[DB OpenSQL:[insertQry UTF8String]];
if(stmt !=nil)
{
sqlite3_bind_text(stmt,1, [dataTextfield.text UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,2, [[selectionarray objectAtIndex:0] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,3, [[selectionarray objectAtIndex:1] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,4, [[selectionarray objectAtIndex:2] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,5, [[selectionarray objectAtIndex:3] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[DB CloseSQL];
以下编码用于更新数据库值
要更新:
NSInteger proeditid = [primarykeyID integerValue];
NSString *updateQry=@"update selection_tbl set expenses_value=?,category=?,date=?,payment=?,description=? where expenses_id=?";
sqlite3_stmt *stmt=[DB OpenSQL:[updateQry UTF8String]];
if(stmt !=nil)
{
sqlite3_bind_text(stmt,1, [dataTextfield.text UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,2, [[selectionarray objectAtIndex:0] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,3, [[selectionarray objectAtIndex:1] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,4, [[selectionarray objectAtIndex:2] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,5, [[selectionarray objectAtIndex:3] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_int(stmt,6, (int)proeditid);
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[DB CloseSQL];
有两个问题:
如何获取图像的NSData
表示?
简单的方法是使用 UIImagePNGRepresentation
的 UIImage
。
更好的方法是使用 getBytes
来检索原始资产。见 .
如何在 SQLite 数据库中保存 NSData
表示?
要将此 NSData
保存在您的数据库中,然后使用 sqlite3_bind_blob
。该过程与您之前与我们分享的 sqlite3_bind_xxx
函数非常相似。使用 NSData
的 bytes
方法访问指向缓冲区的 C 样式指针,并将其传递给 sqlite3_bind_blob
.
请注意,众所周知,在 SQLite 数据库中保存全尺寸图像效率低下。 SQLite 不能很好地处理大的 blob。一般来说,人们更愿意将 NSData
保存到设备永久存储的文档文件夹中的一个文件中,然后只将该文件的 path
保存到数据库中。
在您的代码中添加以下行,这会将图像添加到您的数据库中
sqlite3_bind_blob(stmt,6, [imagData bytes], (unsigned)[imagData length], SQLITE_TRANSIENT);
最终代码如下所示:
NSMutableArray *listItemsarr = [[NSMutableArray alloc] init];
if([listItemsarr count]==0){
NSString *insertQry=@"INSERT INTO selection_tbl (expenses_value,category,date,payment,description,image) VALUES(?,?,?,?,?,?)";
sqlite3_stmt *stmt=[DB OpenSQL:[insertQry UTF8String]];
if(stmt !=nil)
{
sqlite3_bind_text(stmt,1, [dataTextfield.text UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,2, [[selectionarray objectAtIndex:0] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,3, [dateString UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,4, [[selectionarray objectAtIndex:2] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,5, [[selectionarray objectAtIndex:3] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_blob(stmt,6, [imagData bytes], (unsigned)[imagData length], SQLITE_TRANSIENT);
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[DB CloseSQL];
编码为 .m
-(IBAction) getPhoto:(id) sender {
picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
} else {
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
UIAlertView *noCameraAlert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"You don't have a camera for this device" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
//shows above alert if there's no camera
[noCameraAlert show];
}else{
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
picker.allowsEditing = YES;
picker.delegate = self;
}
}
[self presentViewController:picker animated:YES completion:nil];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
UIImage *img = [info objectForKey:UIImagePickerControllerOriginalImage];
img = [info valueForKey:UIImagePickerControllerEditedImage];
self.imageView.image = img;
imagData = UIImagePNGRepresentation(img);
[picker dismissViewControllerAnimated:YES completion:nil];
}
图像现在已放置在图像视图中,我如何将图像保存在数据库中
我已经有了可以插入数据的数据库 要插入:
NSMutableArray *listItemsarr = [[NSMutableArray alloc] init];
if([listItemsarr count]==0){
NSString *insertQry=@"INSERT INTO selection_tbl (expenses_value,category,date,payment,description) VALUES(?,?,?,?,?)";
sqlite3_stmt *stmt=[DB OpenSQL:[insertQry UTF8String]];
if(stmt !=nil)
{
sqlite3_bind_text(stmt,1, [dataTextfield.text UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,2, [[selectionarray objectAtIndex:0] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,3, [[selectionarray objectAtIndex:1] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,4, [[selectionarray objectAtIndex:2] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,5, [[selectionarray objectAtIndex:3] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[DB CloseSQL];
以下编码用于更新数据库值 要更新:
NSInteger proeditid = [primarykeyID integerValue];
NSString *updateQry=@"update selection_tbl set expenses_value=?,category=?,date=?,payment=?,description=? where expenses_id=?";
sqlite3_stmt *stmt=[DB OpenSQL:[updateQry UTF8String]];
if(stmt !=nil)
{
sqlite3_bind_text(stmt,1, [dataTextfield.text UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,2, [[selectionarray objectAtIndex:0] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,3, [[selectionarray objectAtIndex:1] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,4, [[selectionarray objectAtIndex:2] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,5, [[selectionarray objectAtIndex:3] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_int(stmt,6, (int)proeditid);
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[DB CloseSQL];
有两个问题:
如何获取图像的
NSData
表示?简单的方法是使用
UIImagePNGRepresentation
的UIImage
。更好的方法是使用
getBytes
来检索原始资产。见 .
如何在 SQLite 数据库中保存
NSData
表示?要将此
NSData
保存在您的数据库中,然后使用sqlite3_bind_blob
。该过程与您之前与我们分享的sqlite3_bind_xxx
函数非常相似。使用NSData
的bytes
方法访问指向缓冲区的 C 样式指针,并将其传递给sqlite3_bind_blob
.
请注意,众所周知,在 SQLite 数据库中保存全尺寸图像效率低下。 SQLite 不能很好地处理大的 blob。一般来说,人们更愿意将 NSData
保存到设备永久存储的文档文件夹中的一个文件中,然后只将该文件的 path
保存到数据库中。
在您的代码中添加以下行,这会将图像添加到您的数据库中
sqlite3_bind_blob(stmt,6, [imagData bytes], (unsigned)[imagData length], SQLITE_TRANSIENT);
最终代码如下所示:
NSMutableArray *listItemsarr = [[NSMutableArray alloc] init];
if([listItemsarr count]==0){
NSString *insertQry=@"INSERT INTO selection_tbl (expenses_value,category,date,payment,description,image) VALUES(?,?,?,?,?,?)";
sqlite3_stmt *stmt=[DB OpenSQL:[insertQry UTF8String]];
if(stmt !=nil)
{
sqlite3_bind_text(stmt,1, [dataTextfield.text UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,2, [[selectionarray objectAtIndex:0] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,3, [dateString UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,4, [[selectionarray objectAtIndex:2] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(stmt,5, [[selectionarray objectAtIndex:3] UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_blob(stmt,6, [imagData bytes], (unsigned)[imagData length], SQLITE_TRANSIENT);
sqlite3_step(stmt);
}
sqlite3_finalize(stmt);
[DB CloseSQL];