[英]predicateWithFormat NSMutableArray Issue
I have an error with predicateWithFormat causing a crash in my app. 我的predicateWithFormat错误导致我的应用程序崩溃。
The problematic code is: 有问题的代码是:
@implementation SecondViewController
{
NSArray *searchResults;
}
@synthesize jsonConnection, bakeryProductArray, bakeryTableView;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self retrieveData];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - UITableView DataSource
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (tableView == self.searchDisplayController.searchResultsTableView) {
return [searchResults count];
}
else {
return [bakeryProductArray count];
}
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:cellIdentifier];
}
if (tableView == self.searchDisplayController.searchResultsTableView) {
cell.textLabel.text = [searchResults objectAtIndex:indexPath.row];
}
else {
foodProducts *currentProduct = [bakeryProductArray objectAtIndex:indexPath.row];
cell.textLabel.text = currentProduct.productName;
cell.detailTextLabel.text = currentProduct.productName;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
return cell;
}
#pragma mark - UITableView Delegate methods
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (bakeryTableView == self.searchDisplayController.searchResultsTableView) {
[self performSegueWithIdentifier: @"bakeryDetails" sender: self];
}
detailedViewController *productinfo = [self.storyboard instantiateViewControllerWithIdentifier:@"bakeryDetails"];
//Retrieve current user array
foodProducts *currentProduct2 = [bakeryProductArray objectAtIndex:indexPath.row];
productinfo.productName = currentProduct2.productName;
productinfo.productImage = currentProduct2.productImgUrl;
productinfo.productDescription = currentProduct2.productDescription;
productinfo.productPrice = currentProduct2.productPrice;
productinfo.productQuantity = currentProduct2.productquantity;
productinfo.productAllergy = currentProduct2.productAllergy;
[self.navigationController pushViewController:productinfo animated:YES];
[bakeryTableView deselectRowAtIndexPath:indexPath animated:YES];
}
//Becareful here as wrong predicateWithFormat can crash app on keying in search
-(void)filterContentForSearchText:(NSString *)searchText scope:(NSString *)scope
{
NSPredicate *resultPredicate = [NSPredicate predicateWithBlock:^BOOL(NSString * testString, NSDictionary *bindings) {
return ([searchText compare:testString options: NSCaseInsensitiveSearch] == NSOrderedSame);
}];
searchResults = [bakeryProductArray filteredArrayUsingPredicate:resultPredicate];
}
-(BOOL)searchDisplayController:(UISearchDisplayController *)controller
shouldReloadTableForSearchString:(NSString *)searchString
{
[self filterContentForSearchText:searchString
scope:[[self.searchDisplayController.searchBar scopeButtonTitles]
objectAtIndex:[self.searchDisplayController.searchBar
selectedScopeButtonIndex]]];
return YES;
}
#pragma mark - methods
-(void) retrieveData
{
NSURL *url = [NSURL URLWithString:getDataUrl];
NSData *data = [NSData dataWithContentsOfURL:url];
jsonConnection = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
bakeryProductArray = [[NSMutableArray alloc]init];
for (int i = 0; i < jsonConnection.count; i++)
{
NSString *pID = [[jsonConnection objectAtIndex:i] objectForKey:@"id"];
NSString *pName = [[jsonConnection objectAtIndex:i] objectForKey:@"Name"];
NSString *pImageUrl = [[jsonConnection objectAtIndex:i] objectForKey:@"ImageUrl"];
NSString *pDescription = [[jsonConnection objectAtIndex:i] objectForKey:@"Description"];
NSString *pQuantity = [[jsonConnection objectAtIndex:i] objectForKey:@"Quantity"];
NSString *pPrice = [[jsonConnection objectAtIndex:i] objectForKey:@"Price"];
NSString *pAllergy = [[jsonConnection objectAtIndex:i] objectForKey:@"Allergy"];
foodProducts *myProducts = [[foodProducts alloc]initWithproductID:pID andproductName:pName andproductImgUrl:pImageUrl andproductDescription:pDescription andproductquantity:pQuantity andproductPrice:pPrice andproductAllergy:pAllergy];
[bakeryProductArray addObject:myProducts];
}
[self.bakeryTableView reloadData];
}
FoodProduct class 食品类
@implementation foodProducts
@synthesize productID, productName, productImgUrl, productquantity,productDescription, productPrice, productAllergy;
-(id) initWithproductID:(NSString *)uproductID andproductName:(NSString *)uproductName andproductImgUrl:(NSString *)uproductImage andproductDescription:(NSString *)uproductDescription andproductquantity:(NSString *)uproductquantity andproductPrice:(NSString *)uproductPrice andproductAllergy:(NSString *)uproductAllergy
{
self = [super init];
if (self)
{
productID = uproductID;
productName = uproductName;
productImgUrl = uproductImage;
productquantity = uproductquantity;
productDescription = uproductDescription;
productPrice = uproductPrice;
productAllergy = uproductAllergy;
}
return self;
}
The array which is being fed into the NSPredicate is @property (nonatomic, strong) NSMutableArray *bakeryProductArray;
送入NSPredicate的数组是@property @property (nonatomic, strong) NSMutableArray *bakeryProductArray;
Error says: Can't use in/contains operator with collection 错误提示:无法在集合中使用in / contains运算符
Any ideas, on whats going wrong? 有什么想法,怎么了?
Your array does not contain strings , but custom foodProducts
objects. 您的数组不包含字符串 ,而是自定义foodProducts
对象。
To filter the objects by "product name", you would use 要通过“产品名称”过滤对象,您可以使用
[NSPredicate predicateWithFormat:@"productName CONTAINS[cd] %@", searchText];
ADDED: There is another error in your code: 添加:您的代码中还有另一个错误:
cell.textLabel.text = [searchResults objectAtIndex:indexPath.row];
cannot work because the right-hand side does not return a string. 无法使用,因为右侧不返回字符串。 It should be 它应该是
foodProducts *currentProduct = [searchResults objectAtIndex:indexPath.row];
cell.textLabel.text = currentProduct.productName;
NSPredicate *resultPredicate = [NSPredicate predicateWithFormat:@"self.productName contains[cd] %@", searchText]; NSPredicate * resultPredicate = [NSPredicate predicateWithFormat:@“ self.productName contains [cd]%@”,searchText];
NSArray *searchResults = [self.bakeryProductArray filteredArrayUsingPredicate:resultPredicate]; NSArray * searchResults = [self.bakeryProductArrayfilteredArrayUsingPredicate:resultPredicate];
NSLog(@"%@",searchResults); NSLog(@“%@”,searchResults);
If above doesn't work can you show your foodProduct class (model). 如果上述方法不起作用,您可以显示foodProduct类(模型)。
Ideally you should use like[cd] instead of contains[cd]. 理想情况下,您应该使用like [cd]而不是contains [cd]。
Refer: http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/Predicates/Articles/pSyntax.html 1 CONTAINS The left-hand expression contains the right-hand expression. 请参阅: http : //developer.apple.com/library/ios/#documentation/cocoa/conceptual/Predicates/Articles/pSyntax.html 1包含内容左侧表达式包含右侧表达式。
2 LIKE The left hand expression equals the right-hand expression: ? 2 LIKE左手表达式等于右手表达式:? and * are allowed as wildcard characters, where ? 和*允许用作通配符,其中? matches 1 character and * matches 0 or more characters. 匹配1个字符,*匹配0个或更多字符。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.