QCloudSMHGetPresignedURLRequest *req = [QCloudSMHGetPresignedURLRequest new];
// Media Library ID, required parameter
req.libraryId = @"libraryId";
// Space ID, if the media library is in single-tenant mode, this parameter is fixed as a hyphen (-); if the media library is in multi-tenant mode, you must specify this parameter
req.spaceId = @"spaceId";
// version id
req.historyId = @"historVersionId";
// file path
req.filePath = @"filePath";
req.purpose = QCloudSMHPurposePreview;
[req setFinishBlock:^(NSString *result, NSError *_Nullable error) {
    // result preview URL.
}];
[[QCloudSMHService defaultSMHService] getPresignedURL:req];


QCloudSMHGetPresignedURLRequest *req = [QCloudSMHGetPresignedURLRequest new];
// Media Library ID, required parameter
req.libraryId = @"libraryId";
// Space ID, if the media library is in single-tenant mode, this parameter is fixed as a hyphen (-); if the media library is in multi-tenant mode, you must specify this parameter
req.spaceId = @"spaceId";
// version id
req.historyId = @"historVersionId";
// file path
req.filePath = @"filePath";
// number of frames, frame processing targeting gif
req.frameNumber = 10;
// For image transformation parameters like size, scale, heightSize, and widthSize, check the api documentation.
req.size = size;
req.purpose = QCloudSMHPurposePreview;
[req setFinishBlock:^(NSString *result, NSError *_Nullable error) {
    // result preview URL.
}];
[[QCloudSMHService defaultSMHService] getPresignedURL:req];