UiCollectionView单元格选择错误

Question

I have used Alamofire and SwiftyJSON To Populate the UiCollectionview and its working fine but didSelectItemAtIndexPath function shows array out of index thought I have printed the array count and it's not empty

any suggestion

here is my code:-

The model

import Foundation

class ProductModel {
private var _ProductItemId: String!
private var _ProductMainCategory: String!
private var _ProductCategoryId: String!
private var _ProductName: String!
private var _ProductItemNo: String!
private var _ProductAvalaibility: String!
private var _ProductSeoDesc: String!
private var _ProductImageURL: String!
private var _ProductBrand_ID: String!
private var _ProductCat_name: String!

//Level 1
private var _ProductTotalQuantity : String!
private var _Productprice : String!
private var _ProductSalePrice : String!
private var _ProductWeightName : String!
private var _ProductCode : String!




var ProductItemId : String {
    return _ProductItemId
}

var ProductMainCategory : String {
    return _ProductMainCategory
}

var ProductCategoryId : String {
    return _ProductCategoryId
}

var ProductName : String {
    return _ProductName
}

var ProductItemNo : String {
    return _ProductItemNo
}

var ProductAvalaibility : String {
    return _ProductAvalaibility
}

var ProductSeoDesc : String {
    return _ProductSeoDesc
}

var ProductImageURL : String {
    return _ProductImageURL
}

var ProductBrand_ID: String {
    return _ProductBrand_ID
}

var ProductCat_name: String {
    return _ProductCat_name
}

//Level 1
var ProductTotalQuantity : String {
    return _ProductTotalQuantity
}

var Productprice : String {
    return _Productprice
}

var ProductSalePrice : String {
    return _ProductSalePrice
}

var ProductWeightName : String {
    return _ProductWeightName
}

var ProductCode : String {
    return _ProductCode
}



//Initilizer
init(ProductImageURL : String, ProductName : String, Productprice : String, ProductSalePrice : String)
{

    self._ProductName = ProductName
    self._ProductImageURL = ProductImageURL//

    //Level 1
    self._Productprice = Productprice//
    self._ProductSalePrice = ProductSalePrice//

}

My CollectionView Delegates and Data sources

 func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    if let cell = collectionView.dequeueReusableCellWithReuseIdentifier("ProductCell", forIndexPath: indexPath)as? ProductCell {

        let _prod: ProductModel!
            _prod = prod [indexPath.row]
        cell.configureCell(_prod)
        return cell
    }
    else{
        return UICollectionViewCell()
    }


}

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
    let prodDetail: ProductModel!
    prodDetail = prod[indexPath.row] //error Array index out of range 
    print(prodDetail.Productprice)
    performSegueWithIdentifier("productDetailSegue", sender: prodDetail)

}

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    //if inSearchMode{
        //return filteredProd.count
  //  }
    return prod.count
}

func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
    return 1
}

Calling API and Parsing

    Alamofire.request(.POST, "http://www.picknget.com/webservice/index.php/Home/filter_grocery_product_practice/", parameters: parameterDictionary as? [String : AnyObject])
        .responseJSON { response in
            if let value = response.result.value {
                let json = JSON(value)
                print(json)
                if let _statusCode = json["status"].string {
                    // print("the ststus code is ", _statusCode)
                    if (_statusCode == "1"){
                        self.parseJSON(json)
                    }
                    if (_statusCode == "0"){
                        SwiftSpinner.hide({
                            self.callAlert("OOP's", _msg: "No More Product is available in this section right now")
                        })
                    }
                }
                //print ("json result ", json)

            }
        }.responseString { response in
            //print("response ",response.result.value)
    }
}

func parseJSON(json: JSON) {
    for result in json["cat"].arrayValue {
        let name = result["Name"]

        let aString: String = "\(result["ImageURL"])"
        let product_Image_Url  = aString.stringByReplacingOccurrencesOfString("~", withString: "http://www.picknget.com", options: NSStringCompareOptions.LiteralSearch, range: nil)
        let price = result["cat_price"][0]["Price"].string
        let SalePrice = result["cat_price"][0]["SalePrice"].string


        let product = ProductModel(ProductImageURL: "\(product_Image_Url)", ProductName: "\(name)", Productprice: "\(price!)", ProductSalePrice: "\(SalePrice!)")
        prod.append(product)
    }

    print("@@@@@@@@")
    print(prod.count)
    dispatch_async(dispatch_get_main_queue(),{
        self.productCollect.reloadData()
    });
}

Answer 1

According your comments, I believe the issue is related to how you set the obtained Products for the Collection View.

It's very likely that the function parseJSON executes on a secondary thread. This is actually, the same execution context of the completion handler of method responseJSON .

Within function parseJSON you have this statement:

    prod.append(product)

Here, prod should not be a global variable or not a member variable of the view controller! Make it a local variable in function parseJSON !

Your view controller should have a property of this array as well, eg products . This serves as the "model" of the view controller. It will be accesses only from the main thread.

In parseJSON assign the view controller the products as follows:

func parseJSON(json: JSON) {
    var tmpProducts: [Product] = []
    for result in json["cat"].arrayValue {
        let name = result["Name"]

        let aString: String = "\(result["ImageURL"])"
        let product_Image_Url  = aString.stringByReplacingOccurrencesOfString("~", withString: "http://www.picknget.com", options: NSStringCompareOptions.LiteralSearch, range: nil)
        let price = result["cat_price"][0]["Price"].string
        let SalePrice = result["cat_price"][0]["SalePrice"].string


        let product = ProductModel(ProductImageURL: "\(product_Image_Url)", ProductName: "\(name)", Productprice: "\(price!)", ProductSalePrice: "\(SalePrice!)")
        tmpProducts.append(product)
    }

    dispatch_async(dispatch_get_main_queue(),{
        self.products = tmpProducts   // assuming `self` is the ViewController
        self.productCollect.reloadData()
    });
}

Note: you need to change your Data Source Delegates accordingly, eg accessing the "model" ( self.products.count ) etc.