What is the proper method or keyword to put in a user-defined method that renames a variable in C#?

问题

this is part of my code:

private void button1_Click(object sender, EventArgs e)
{
    int Chocolate = int.Parse(QtyChocolate.Text);
    TableUpdate("Chocolate", QtyChocolate.Text);
    int Vanilla = int.Parse(QtyVanilla.Text);
    TableUpate("Vanilla", QtyVanilla.Text);
    int Strawberry = int.Parse(QtyStrawberry.Text);
    TableUpate("Strawberry", QtyStrawberry.Text);
    int Melon = int.Parse(QtyMelon.Text);
    TableUpate("Melon", QtyMelon.Text);
    int Mint = int.Parse(QtyMint.Text);
    TableUpate("Mint", QtyMint.Text);
    int Marijuana = int.Parse(QtyMarijuana.Text);
    TableUpate("Marijuana", QtyMarijuana.Text);

    Machinefunction1(a bunch of parameters here including some of the int ingredients);
    Machinefunction55(a different bunch of parameters here including some of the int ingredients);
    //...and hundreds more ingredients... These integer values parsed from corresponding
    //textboxes will be used as parameters in various functions of the machine.    
}

I'm trying to create a method to simplify the code and this is what I attempted but failed:

private void MyFunc(Ingredient, string text) //What method or keyword should precede Ingredient?
{
    int Ingredient = int.Parse(text);
    TableUpdate("Ingredient", text);
}
private void button1_Click(object sender, EventArgs e)
{
    MyFunc(Chocolate, QtyChocolate.Text); //This will recall my method to produce the named integers
    MyFunc(Vanilla, QtyVanilla.Text);
    //...and so on...

    Machinefunction1(a bunch of parameters here including some of the int ingredients);
    Machinefunction55(a different bunch of parameters here including some of the int ingredients);
}

Please help, thank you. Apologies for any inconvenience caused.

回答1:

Do you want something like out (which allows a function to instantiate a variable in the calling method)?:

private void MyFunc(string ingredientName, string text, out int ingredientQty)
{    
     ingredientQty = int.Parse(text);
     TableUpdate(ingredientName, text);
}

int Chocolate;
MyFunc(nameof(Chocolate), txtChocolateQty.Text, out Chocolate);

nameof will replace it with a string "Chocolate" at compile time by looking at the variable name.

Alternatively, with C#7 you can declare the int inline:

MyFunc("Chocolate", txtChocolateQty.Text, out int Chocolate);

Edit (with TryParse):

private bool MyFunc(string ingredientName, string text, out int ingredientQty)
{    
     if (!int.TryParse(text, out ingredientQty))
     {
         return false;
     }
     TableUpdate(ingredientName, text);
     return true;
}

usage:

if (MyFunc("Chocolate", txtChocolateQty.Text, out int Chocolate))
{
    // it was successful! yay!
}

回答2:

I would suggest that you look at doing something like this:

private void button1_Click(object sender, EventArgs e)
{
    var ingredients = new Dictionary<string, int>()
    {
        { "Chocolate", int.Parse(QtyChocolate.Text) },
        { "Vanilla", int.Parse(QtyVanilla.Text) },
        { "Strawberry", int.Parse(QtyStrawberry.Text) },
        { "Melon", int.Parse(QtyMelon.Text) },
        { "Mint", int.Parse(QtyMint.Text) },
        { "Marijuana", int.Parse(QtyMarijuana.Text) },
    }

    foreach (var ingredient in ingredients)
    {
        TableUpdate(ingredient.Key, ingredient.Value.ToString());
    }
}

Using separate variables for each ingredient and using out parameters, while legal C#, often just makes the code hard to read.

来源：https://stackoverflow.com/questions/50402927/what-is-the-proper-method-or-keyword-to-put-in-a-user-defined-method-that-rename

标签

parsing

variables

int

user-defined