Spritekit如何根據觸摸和按住的位置運行SKAction

Question

因此，我嘗試在游戲中實現一種方法，如果玩家的手指在y軸或更低的方向上觸摸屏幕（例如說50），則SKAction將運行以將角色精靈向下移動，並且如果他們的手指在觸摸高於50，另一個動作將使精靈向上移動。 我不知道您如何將它識別為觸摸並按住。 請幫助。

Answer 1

您需要捕獲用戶的觸摸事件才能完成此操作。 我建議您查看RayWenderlich提供的出色的教程，該教程位於： 動畫紋理和通過觸摸事件移動它們

如果您沒有時間這樣做，那么您的代碼可能會像這樣：

首先，您需要了解的是兩個最通用的觸摸事件：-（void）touchesEnded：（NSSet *）touches withEvent：（UIEvent *）event和：-( void）touchesBegan：（NSSet *）touches withEvent：（UIEvent *）event

基本上，當用戶將手指放在屏幕上時，將開始觸摸開始方法，而當用戶將手指從屏幕上移開時，將結束觸摸結束方法。

在此示例中，我將使用touchesEnded，但可以隨意更改它，就像將“ Ended”與“ Began”切換一樣容易。

我將向您展示的所有代碼都將在場景實現文件中進行：

如果只想讓精靈在特定點之上向上移動而在特定點之下向下移動，請使用以下命令：

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    //capture the location of the touch
    CGPoint location = [[touches anyObject] locationInNode:self];

    //used to hold the location to travel
    CGPoint moveLocation;

    //check if the Y location is less than 50
    if(location.y < 50)
    {
        //the the location to the bottom of the screen
         moveLocation = CGPointMake(sprite.position.x, 0);
    }
    //and then if its more than 50
    else
    {
        //set the locaiton to the top of the screen
        moveLocation = CGPointMake(sprite.position.x, self.frame.size.height);
    }

    //move the sprite

    //Check if their already moving
    if(sprite actionForKey:@"moving")
    {
        //If they are stop them so they can move in the new direction
        [sprite removeActionForKey:@"moving"];
    }
    SKAction *moveAction = [SKAction moveTo:location duration:5.0f];

    //remember to give the action a key so that we can check for it during the above if statement
    [sprite runAction:moveAction withKey:@"moving"];
}

那里有它。 唯一的缺陷是，無論您與該位置的距離如何，到達該位置始終需要5秒鍾，請繼續閱讀以下內容，以獲取有關如何更正該位置的提示，或者如果您想了解如何使該精靈移動到任何位置觸摸屏幕上的位置。

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    //capture the location of the touch
    CGPoint location = [[touches anyObject] locationInNode:self];

    //move the sprite

    //Check if their already moving
    if(sprite actionForKey:@"moving")
    {
        //If they are stop them so they can move in the new direction
        [sprite removeActionForKey:@"moving"];
    }
    SKAction *moveAction = [SKAction moveTo:location duration:5.0f];

    //remember to give the action a key so that we can check for it during the above if statement
    [sprite runAction:moveAction withKey:@"moving"];
}

該代碼將使其保持原狀，以便在5秒鍾內將精靈移動到屏幕上觸摸的位置。 只要記住用您的SKSpriteNode變量的名稱替換“ sprite”的實例即可。 對於更復雜的運動，請嘗試以下操作：

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    //capture the location of the touch
    CGPoint location = [[touches anyObject] locationInNode:self];
    //set the velocity of the subject
    float velocity = self.frame.size.width/3.0;
    //The above will ensure that it will take the sprite 3 seconds to travel the distance of the screen

    //Determine the difference between the point touched and the sprites position
    CGPoint moveDifference = CGPointMake(location.x - sprite.position.x, location.y - sprite.position.y);

    //Use pythagorean theorem to figure out the actual length to move
    float distanceToMove = sqrtf(moveDifference.x * moveDifference.x + moveDifference.y*moveDifference.y);

    //Use the distance to travel and the velocity to determine how long the sprite should move for
    float moveDuration = distanceToMove / velocity;

    //and finally move the sprite
    if(sprite actionForKey:@"moving")
    {
        [sprite removeActionForKey:@"moving"];
    }
    SKAction *moveAction = [SKAction moveTo:location duration:moveDuration];

    [sprite runAction:moveAction withKey:@"moving"];
}

這將為子畫面設置速度，確定行進的長度，以及到達新位置所需的時間。

如果要涉及紋理，我強烈建議您閱讀我提供的鏈接。

根據要求，我將很高興提供使用力來控制運動速度的示例。

希望能對您有所幫助，讓我知道我是否有可以運行代碼的位置，但是我確定這是可以的。