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看看我的第一个应用程序，我在正确的轨道上吗？我有一个简单的表单，用户输入要在数组中查找的值。如果找到带有索引的返回值。我使用 VS 2019/C#。

   private async void ButtonSingleGetValues_Click(object sender, RoutedEventArgs e)
    {
        //Tasks:
        //Get Value from TextBox on Form 
        //Validate TextBox (TextBoxSingleArray.Text) is a number
        //Check if Number exists in Array
        //Number Exists, Return Number to Form  TextBox to show it exists
        //then return Index of Number to Form TextBox in Array

        //Here is the single Array
        int[] singleDimension = new int[5] { 1, 5, 10, 15, 20 };
        //Grab value from user input textbox for single array          
        bool intSingleTryParse = int.TryParse(TextBoxSingleArray.Text, out int ValueSingle);
        if (intSingleTryParse)   //bool is true, continue 
        {

            int ArrayValue = Array.Find(singleDimension, element => element == ValueSingle);
            if (ArrayValue > 0)
            {
                TextBoxSingleArrayValue.Text = ArrayValue.ToString();
                int ArrayPosition = Array.IndexOf(singleDimension, ValueSingle);
                TextBoxSinglePosition.Text = ArrayPosition.ToString();
            }
            else
            {
                MessageDialog MsgNotFound = new MessageDialog("Did not find number in array!");
                await MsgNotFound.ShowAsync();
            }
        }
        else
        {
            MessageDialog MsgNope = new MessageDialog("You not a number!");
            await MsgNope.ShowAsync();
        }
    }
}

}

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1 回答 1

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我的版本是：

   private async void ButtonSingleGetValues_Click(object sender, RoutedEventArgs e)
    {
        //I wouldn't use the word "single" in an array of ints because single is a floating point number type
        //use plurals for collections 
        //do not need to specify array size with initializer 
        int[] numbers = new int[] { 1, 5, 10, 15, 20 };

        //name your result bool more simply, do not mention single
        //name your text box more simply         
        //windows controls like textbox tend to be named with the textbox word at the end
        bool success = int.TryParse(FindIntTextBox.Text, out int findInt);

        //personally, I prefer "test bad input, then return if it's bad"
        //instead of ending up with nested nested code blocks that run for screens at a time
        //it's kinda anathema to the "never use return mid method" crowd though
        if (!success)
        {
          await new MessageDialog("Not a valid integer in the ... box").ShowAsync();
          return;
        }

        //local variables are namedLikeThis, private are typically _namedLikeThis and public are NamedLikeThis
        //do not use Array.Find on simple ints etc: you know what you're finding
        //array.Find would be used for looking up eg a person by name
        //you already know the value to find and just want its index
        int foundIndex = Array.IndexOf(numbers, findInt);

        //If there is a way to structure a test so that there is
        //either a resulting one line operation to perform or a ten line op, i 
        //tend to place the the shorter code in the if and the longer
        //code in the else. This way the condition that applies to
        //the else is likely still visible on screen whereas if the if is
        //long the else can lose meaning without a scroll. I could
        //also have used the "if bad return" here but I do subscribe
        //to "avoid return mid method if possible" and we've already started our processing
        if(foundIndex == -1)
          await new MessageDialog("not a known number").ShowAsync();
        else 
        {
           //not sure why you'd bother unless the int parse tolerated eg spaces
          FindIntTextBox.Text = findInt.ToString();
          FoundIndexTextBox.Text = foundIndex.ToString();
        }
    }
}

我会让异步等待调用单行await x.YAsync(z);，而不是仅为任务声明一个变量。我们倾向于只在需要创建任务，做更多工作，然后等待任务时才这样做

于 2020-08-06T05:58:02.913 回答