有沒有辦法打破一個返回void的函數？

Question

我有一個函數，為給定另一個tile的特定tile設置繪制狀態。 繪制狀態將更改的圖塊比較周圍的圖塊然后相應地更新。 我將嘗試在下面說明

[b] [b] [a]
[b] [a] [a]
[a] [a] [a]  where a = sand && b = water

當a檢測到b正在接近它時，它必須更新其繪制狀態。 所以我有一個適用於大寫，小寫，左大小寫和右大小寫的函數。 我現在需要修改該功能，以便它可以處理左右情況，右上角情況，右下角情況等。這是我的功能

public override void CompareBorderingTiles(Tile T)
    {
        if (T is Water)
        {
            float leftBound = location.X - (Tile.TileWidth * Tile.TileScale);
            float rightBound = location.X + (Tile.TileWidth * Tile.TileScale);
            float upperBound = location.Y - (Tile.TileHieght * Tile.TileScale);
            float bottomBound = location.Y + (Tile.TileHieght * Tile.TileScale);
            if (T.GridLocation.X == leftBound)
            {
                drawstate = DrawState.Left;
            }
            if (T.GridLocation.X == rightBound)
                drawstate = DrawState.Right;
            if (T.GridLocation.Y == upperBound)
                drawstate = DrawState.Upper;
            if (T.GridLocation.Y == bottomBound)
                drawstate = DrawState.Lower; 
        }

        base.CompareBorderingTiles(T);
    }

對於為什么我想要突破這個功能，或者可能不是這個功能，它應該是非常明確的解釋。 基本上我有一個枚舉，告訴我我的繪制狀態是什么（drawstate是枚舉）。 誰能告訴我是否可以設置正確的繪制狀態然后退出我的功能？

Answer 1

只需使用您想要結束的return語句：

return;

所以，在您的代碼中，您可以這樣做：

public override void CompareBorderingTiles(Tile T)
{
    if (T is Water)
    {
        float leftBound = location.X - (Tile.TileWidth * Tile.TileScale);
        float rightBound = location.X + (Tile.TileWidth * Tile.TileScale);
        float upperBound = location.Y - (Tile.TileHieght * Tile.TileScale);
        float bottomBound = location.Y + (Tile.TileHieght * Tile.TileScale);
        if (T.GridLocation.X == leftBound)
        {
            drawstate = DrawState.Left;
            return;
        }
        if (T.GridLocation.X == rightBound)
        {
            drawstate = DrawState.Right;
            return;
        }
        if (T.GridLocation.Y == upperBound)
        {
            drawstate = DrawState.Upper;
            return;
        }
        if (T.GridLocation.Y == bottomBound)
        {
            drawstate = DrawState.Lower; 
            return;
        }
    }

    base.CompareBorderingTiles(T);
}

Answer 2

只需使用return; 就其本身而言，這將立即從函數“返回”。

雖然你真的需要回歸嗎？

   if (T.GridLocation.X == leftBound)
    {
        drawstate = DrawState.Left;
    }
    else if (T.GridLocation.X == rightBound)
    {
        drawstate = DrawState.Right;
    }

    else if (T.GridLocation.Y == upperBound)
    {
        drawstate = DrawState.Upper;
    }
    else if (T.GridLocation.Y == bottomBound)
    {
        drawstate = DrawState.Lower; 
    }

這應該使代碼在未來更容易維護。

Answer 3

您可以使用return退出函數。

Answer 4

你可以使用return; 在函數的任何一點，它將在那里離開函數。 使用return意味着不會調用您的基函數。 如果您需要基本函數被調用使用else if那么，當你條件滿足，就不會檢查剩余的if語句：

public override void CompareBorderingTiles(Tile T)
    {
        if (T is Water)
        {
            float leftBound = location.X - (Tile.TileWidth * Tile.TileScale);
            float rightBound = location.X + (Tile.TileWidth * Tile.TileScale);
            float upperBound = location.Y - (Tile.TileHieght * Tile.TileScale);
            float bottomBound = location.Y + (Tile.TileHieght * Tile.TileScale);
            if (T.GridLocation.X == leftBound)
            {
                drawstate = DrawState.Left;
            }
            else if (T.GridLocation.X == rightBound)
                drawstate = DrawState.Right;
            else if (T.GridLocation.Y == upperBound)
                drawstate = DrawState.Upper;
            else if (T.GridLocation.Y == bottomBound)
                drawstate = DrawState.Lower; 
        }

        base.CompareBorderingTiles(T);
    }

Answer 5

使用return; 該函數將作為void返回