我不知道如何解决代码，因为我一直有java.lang.NumberFormatException: For输入字符串的反馈："“

Question

这个项目是电子商务应用程序上的一项任务，我很乐意得到帮助。我正在尝试检查产品数量是否大于Firestore控制台中的购物车中的产品，但我一直存在NumberFormatException错误。下面是当用户试图增加给出错误的订单数量时的代码

 holder.itemView.findViewById<ImageButton>(R.id.ib_add_cart_item).setOnClickListener {
    // converting the carQuantity to Int from String
    val cartQuantity: Int = cartProductItemListModel.cart_quantity.toInt()

          
    // check if the cart_quantity is less than the stock_quantity
    if (cartQuantity < cartProductItemListModel.product_quantity.toInt()){
            val itemHashMap = HashMap<String, Any>()
            itemHashMap[Constants.CART_QUANTITY] = (cartQuantity + 1).toString()
            if (context is CartListActivity){
                context.showProgressDialogue("Updating Cart")
            }
            FirestoreClass().updateMyCartItem(context, cartProductItemListModel.id, itemHashMap)
    } else{
        if (context is CartListActivity){
            Toast.makeText(context, "Available stock for your order is (${cartProductItemListModel.product_quantity}). " +
                    "You can not add more than stock quantity", Toast.LENGTH_LONG).show()
        }
    }
}

调试控制台中的错误如下

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.hardextech.store, PID: 9807
java.lang.NumberFormatException: For input string: ""
    at java.lang.Integer.parseInt(Integer.java:627)
    at java.lang.Integer.parseInt(Integer.java:650)
    at com.hardextech.store.ui.activities.ui.adapter.CartItemListAdapter.onBindViewHolder$lambda-4(CartItemListAdapter.kt:126)
    at com.hardextech.store.ui.activities.ui.adapter.CartItemListAdapter.$r8$lambda$cL9k5ufbU_up2kCEhVgh9sgpi9I(Unknown Source:0)
    at com.hardextech.store.ui.activities.ui.adapter.CartItemListAdapter$$ExternalSyntheticLambda3.onClick(Unknown Source:4)
    at android.view.View.performClick(View.java:7044)
    at android.view.View.performClickInternal(View.java:7017)
    at android.view.View.access$3200(View.java:784)
    at android.view.View$PerformClick.run(View.java:26596)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6819)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:497)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:912)

减少订单数量的代码工作得很好，这与用户增加订单时相似。

  holder.itemView.findViewById<ImageButton>(R.id.ib_remove_cart_item).setOnClickListener {
    // when the user clicks on the remove imageButton
    if (cartProductItemListModel.cart_quantity == "1"){
        // perform the same end function as when the user clicks on the delete button
        FirestoreClass().deleteItemFromCart(context, cartProductItemListModel.id)
       } else{
           // converting the cart_quantity from string to Int
           val cartQuantity: Int = cartProductItemListModel.cart_quantity.toInt()
        // creating an HashMap for updating the changes
           val itemHashMap = HashMap<String, Any>()
           itemHashMap[Constants.CART_QUANTITY] = (cartQuantity - 1).toString()

           //show the progress Dialogue
           if (context is CartListActivity){
               context.showProgressDialogue("Updating Cart")
           }
           FirestoreClass().updateMyCartItem(context, cartProductItemListModel.id, itemHashMap)
       }
}

Answer 1

如果您试图将"“解析为int，它将通过相同的异常，在调用toInt之前确保字符串不是空的或空的。