列表索引超出范围

我试图从组合框中检索一个值，并使用列表将其置于另一个组合框中。列表索引超出范围

我成功从列表中删除了该值，并将其实施到其他列表中。但是当我这样做时，我的清单容量出现故障，并且索引超出了界限错误。

场景：

List Letter Selected: B

'Left Shift Button Pressed'

'B' Removed from Letters List

'B' Added to Numbers List

Print Out Values

Error: "Index was out of range. Must be non-negative and less than the size of collection

Line 66: Console.WriteLine("Numbers: " + numbers[i] + "\tIteration: " + i);

Number List Capacity: 8, Letters List Capacity: 4.

Number List: 1, 2, 3, 4, B. Letters List: A, C, D

CODE：

public partial class Form1 : Form 
{ 
    public List<string> letters = new List<string>(); 
    public List<string> numbers = new List<string>(); 

    public Form1() 
    { 
     InitializeComponent(); 
    } 

    private void Form1_Load(object sender, EventArgs e) 
    { 
     InitialiseLists(); 
     LoadListsIntoCombo(); 
    } 

    public void InitialiseLists() 
    { 
     /* 
     * Add Letter Data 
     */ 
     letters.Add("A"); 
     letters.Add("B"); 
     letters.Add("C"); 
     letters.Add("D"); 

     /* 
     * Add Number Data 
     */ 
     numbers.Add("1"); 
     numbers.Add("2"); 
     numbers.Add("3"); 
     numbers.Add("4"); 

    } 

    public void LoadListsIntoCombo() 
    { 

     comboLetter.DataSource = letters; 
     comboNumber.DataSource = numbers; 

    } 

    public void PrintList() 
    { 
     /* 
     * Print Lists To Console 
     */ 
     for (int i = 0; i < numbers.Capacity; i++) 
     { 
      Console.WriteLine("NUM CAPACITY: " + numbers.Capacity); 
      Console.WriteLine("Numbers: " + numbers[i] + "\tIteration: " + i); 
     } 

     for (int i = 0; i < letters.Capacity; i++) 
     { 
      Console.WriteLine("LET CAPACITY: " + letters.Capacity); 
      Console.WriteLine("Letters : " + letters[i] + "\tIteration: " + i); 

     } 

    } 


    private void cmdLeft_Click(object sender, EventArgs e) 
    { 

     AddLetterToNumber(GetLetter()); 
     RemoveLetter(GetLetter()); 

    } 

    public void RemoveLetter(string value) 
    { 
     letters.Remove(value); 
    } 

    public void AddLetterToNumber(string value) 
    { 
     numbers.Add(value); 
    } 

    public string GetLetter() 
    { 
     string letter = comboLetter.SelectedItem.ToString(); 
     return letter; 
    } 

    public int GetLetterIndex() 
    { 
     int letterIndex = comboLetter.SelectedIndex; 

     return letterIndex; 
    } 

    private void cmdRight_Click(object sender, EventArgs e) 
    { 
     PrintList(); 
    } 

} 

    }

任何帮助，您可以提供非常感谢。

来源

2012-10-21 speak

使用Count属性而不是Capacity。因为第一个返回列表中包含的项目的数量。第二个就是说在调整列表之前可以添加多少项。

public void PrintList() 
{ 
    Console.WriteLine("Numbers count: " + numbers.Count);  
    for (int i = 0; i < numbers.Count; i++) 
     Console.WriteLine("Numbers: {0}\tIteration: {1}", numbers[i], i);  

    Console.WriteLine("Letters count: " + letters.Count);  
    for (int i = 0; i < letters.Count; i++)  
     Console.WriteLine("Letters : {0}\tIteration: {1}", letters[i], i); 
}

来源

2012-10-21 00:59:51

还是'foreach'条款。 –

非常感谢你这么快的回复 - 非常感谢。时间限制后会接受。 – speak

@LuiggiMendoza我把总数显示为循环外。但'for循环在这里是很好的，因为OP希望显示索引 –

您正在使用容量而不是计数。容量不是列表中的元素数量。

Capacity: Gets or sets the total number of elements the internal data structure can hold without resizing. 
    Count: Gets the number of elements actually contained in the List<T>.

从这里 http://msdn.microsoft.com/en-us/library/6sh2ey19.aspx

来源

2012-10-21 01:01:53 madmik3

感谢您的回复和解释，非常感谢。 – speak

列表索引超出范围

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