我必须在表视图控制器和详细视图控制器之间传递数据，我正在使用Parse从后端加载数据，我用本地数据做这个，这是源代码：
表视图控制器：
#import "RecipeBookViewController.h"
#import "RecipeDetailViewController.h"
#import "Recipe.h"
@interface RecipeBookViewController ()
@end
@implementation RecipeBookViewController {
NSArray *recipes;
}
@synthesize tableView = _tableView;
- (void)viewDidLoad
{
[super viewDidLoad];
// Initialize table data
// recipes = [NSArray arrayWithObjects:@"Egg Benedict", @"Mushroom Risotto", @"Full Breakfast", @"Hamburger", @"Ham and Egg Sandwich", @"Creme Brelee", @"White Chocolate Donut", @"Starbucks Coffee", @"Vegetable Curry", @"Instant Noodle with Egg", @"Noodle with BBQ Pork", @"Japanese Noodle with Pork", @"Green Tea", @"Thai Shrimp Cake", @"Angry Birds Cake", @"Ham and Cheese Panini", nil];
Recipe *recipe1 = [Recipe new];
recipe1.name = @"Egg Benedict";
recipe1.prepTime = @"30 min";
recipe1.imageFile = @"egg_benedict.jpg";
recipe1.ingredients = [NSArray arrayWithObjects:@"2 fresh English muffins", @"4 eggs", @"4 rashers of back bacon", @"2 egg yolks", @"1 tbsp of lemon juice", @"125 g of butter", @"salt and pepper", nil];
Recipe *recipe2 = [Recipe new];
recipe2.name = @"Mushroom Risotto";
recipe2.prepTime = @"30 min";
recipe2.imageFile = @"mushroom_risotto.jpg";
recipe2.ingredients = [NSArray arrayWithObjects:@"1 tbsp dried porcini mushrooms", @"2 tbsp olive oil", @"1 onion, chopped", @"2 garlic cloves", @"350g/12oz arborio rice", @"1.2 litres/2 pints hot vegetable stock", @"salt and pepper", @"25g/1oz butter", nil];
Recipe *recipe3 = [Recipe new];
recipe3.name = @"Full Breakfast";
recipe3.prepTime = @"20 min";
recipe3.imageFile = @"full_breakfast.jpg";
recipe3.ingredients = [NSArray arrayWithObjects:@"2 sausages", @"100 grams of mushrooms", @"2 rashers of bacon", @"2 eggs", @"150 grams of baked beans", @"Vegetable oil", nil];
Recipe *recipe4 = [Recipe new];
recipe4.name = @"Hamburger";
recipe4.prepTime = @"30 min";
recipe4.imageFile = @"hamburger.jpg";
recipe4.ingredients = [NSArray arrayWithObjects:@"400g of ground beef", @"1/4 onion (minced)", @"1 tbsp butter", @"hamburger bun", @"1 teaspoon dry mustard", @"Salt and pepper", nil];
Recipe *recipe5 = [Recipe new];
recipe5.name = @"Ham and Egg Sandwich";
recipe5.prepTime = @"10 min";
recipe5.imageFile = @"ham_and_egg_sandwich.jpg";
recipe5.ingredients = [NSArray arrayWithObjects:@"1 unsliced loaf (1 pound) French bread", @"4 tablespoons butter", @"2 tablespoons mayonnaise", @"8 thin slices deli ham", @"1 large tomato, sliced", @"1 small onion", @"8 eggs", @"8 slices cheddar cheese", nil];
Recipe *recipe6 = [Recipe new];
recipe6.name = @"Creme Brelee";
recipe6.prepTime = @"1 hour";
recipe6.imageFile = @"creme_brelee.jpg";
recipe6.ingredients = [NSArray arrayWithObjects:@"1 quart heavy cream", @"1 vanilla bean, split and scraped", @"1 cup vanilla sugar", @"6 large egg yolks", @"2 quarts hot water", nil];
Recipe *recipe7 = [Recipe new];
recipe7.name = @"White Chocolate Donut";
recipe7.prepTime = @"45 min";
recipe7.imageFile = @"white_chocolate_donut.jpg";
recipe7.ingredients = [NSArray arrayWithObjects:@"3 1/4 cups flour", @"2 teaspoons baking powder", @"1/4 teaspoon salt", @"2 beaten eggs", @"2/3 cup sugar", @"2 ounces melted white chocolate", @"1/2 cup milk", nil];
Recipe *recipe8 = [Recipe new];
recipe8.name = @"White Chocolate Mocha";
recipe8.prepTime = @"5 min";
recipe8.imageFile = @"starbucks_coffee.jpg";
recipe8.ingredients = [NSArray arrayWithObjects:@"2/3 cup whole milk", @"6 tablespoons white chocolate chips", @"coffee", @"whipped cream", nil];
Recipe *recipe9 = [Recipe new];
recipe9.name = @"Vegetable Curry";
recipe9.prepTime = @"30 min";
recipe9.imageFile = @"vegetable_curry.jpg";
recipe9.ingredients = [NSArray arrayWithObjects:@"1 tablespoon olive oil", @"1 onion, chopped", @"2 cloves garlic", @"2 1/2 tablespoons curry powder", @"2 quarts hot water", nil];
Recipe *recipe10 = [Recipe new];
recipe10.name = @"Instant Noodle with Egg";
recipe10.prepTime = @"8 min";
recipe10.imageFile = @"instant_noodle_with_egg.jpg";
recipe10.ingredients = [NSArray arrayWithObjects:@"1 pack of Instant Noodle", @"2 eggs", nil];
Recipe *recipe11 = [Recipe new];
recipe11.name = @"Noodle with BBQ Pork";
recipe11.prepTime = @"20 min";
recipe11.imageFile = @"noodle_with_bbq_pork.jpg";
recipe11.ingredients = [NSArray arrayWithObjects:@"1 pack of Instant Noodle", @"BBQ pork", @"Salt and Pepper", nil];
Recipe *recipe12 = [Recipe new];
recipe12.name = @"Japanese Noodle with Pork";
recipe12.prepTime = @"20 min";
recipe12.imageFile = @"japanese_noodle_with_pork.jpg";
recipe12.ingredients = [NSArray arrayWithObjects:@"1 pack of Japanese Noodle", @"2 green onions", @"2 garlic cloves, minced", @"4 boneless pork loin chops", nil];
Recipe *recipe13 = [Recipe new];
recipe13.name = @"Green Tea";
recipe13.prepTime = @"5 min";
recipe13.imageFile = @"green_tea.jpg";
recipe13.ingredients = [NSArray arrayWithObjects:@"Green tea", nil];
Recipe *recipe14 = [Recipe new];
recipe14.name = @"Thai Shrimp Cake";
recipe14.prepTime = @"1.5 hours";
recipe14.imageFile = @"thai_shrimp_cake.jpg";
recipe14.ingredients = [NSArray arrayWithObjects:@"8 oz (250g) peeled and deveined raw shrimp", @"2 tablespoons red curry paste", @"1 large egg", @"2 teaspoon fish sauce", @"1 tablespoon sugar", @"2 tablespoons coconut milk", @"2 tablespoons roughly chopped Thai basil leaves", nil];
Recipe *recipe15 = [Recipe new];
recipe15.name = @"Angry Birds Cake";
recipe15.prepTime = @"4 hours";
recipe15.imageFile = @"angry_birds_cake.jpg";
recipe15.ingredients = [NSArray arrayWithObjects:@"12 tablespoons (1 1/2 sticks) unsalted butter", @"2 1/2 cups all-purpose flour", @"1 tablespoon baking powder", @"1 teaspoon salt", @"1 3/4 cups sugar", @"2 large eggs, plus 3 large egg yolks", @"1 cup of milk", nil];
Recipe *recipe16 = [Recipe new];
recipe16.name = @"Ham and Cheese Panini";
recipe16.prepTime = @"10 min";
recipe16.imageFile = @"ham_and_cheese_panini.jpg";
recipe16.ingredients = [NSArray arrayWithObjects:@"2 tablespoons unsalted butter", @"4 cups thinly sliced shallots", @"2 teaspoons fresh thyme", @"1/4 cup grainy Dijon mustard", @"8 slices rustic white bread", @"8 slices Gruyere cheese", @"8 ounces sliced cooked ham", nil];
recipes = [NSArray arrayWithObjects:recipe1, recipe2, recipe3, recipe4, recipe5, recipe6, recipe7, recipe8, recipe9, recipe10, recipe11, recipe12, recipe13, recipe14, recipe15, recipe16, nil];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [recipes count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = @"RecipeCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
}
Recipe *recipe = [recipes objectAtIndex:indexPath.row];
cell.textLabel.text = recipe.name;
return cell;
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:@"showRecipeDetail"]) {
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
RecipeDetailViewController *destViewController = segue.destinationViewController;
destViewController.recipe = [recipes objectAtIndex:indexPath.row];
// Hide bottom tab bar in the detail view
// destViewController.hidesBottomBarWhenPushed = YES;
}
}
详情视图控制器：
@interface RecipeDetailViewController ()
@end
@implementation RecipeDetailViewController
@synthesize recipePhoto;
@synthesize prepTimeLabel;
@synthesize ingredientTextView;
@synthesize recipe;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
self.title = recipe.name;
self.prepTimeLabel.text = recipe.prepTime;
self.recipePhoto.image = [UIImage imageNamed:recipe.imageFile];
NSMutableString *ingredientText = [NSMutableString string];
for (NSString* ingredient in recipe.ingredients) {
[ingredientText appendFormat:@"%@\n", ingredient];
}
self.ingredientTextView.text = ingredientText;
}
- (void)viewDidUnload
{
[self setRecipePhoto:nil];
[self setPrepTimeLabel:nil];
[self setIngredientTextView:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
@end
如何使用Parse.com后端执行此操作？
答案 0 :(得分：0)
假设您在Parse后端有一个Recipe类，您应该能够简单地替换初始化程序中使用Parse查询创建配方的代码，以便检索它们。类似下面的内容（注意我没有完全检查语法）：
PFQuery *recipeQuery = [PFQuery queryWithClassName:@"Recipe"];
[recipeQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
self.recipes = <Map parse objects to Recipe objects here>;
}
}];
如果将返回的Parse对象映射到Recipe个对象，除了处理通过网络加载内容的延迟之外，您不需要更改任何其余代码（您可能想要向用户显示某种加载指示器。）
或者，您可以查看Parse框架提供的PFQueryTableViewController，它可能会完成您所需的一切。