从另一个类调用计划方法时发生SIGABRT错误

Question

你好，我正在制作一个侧面滚动的Cocos2d游戏，我正在将敌人融入游戏中，这样当一个敌人被干掉时，另一个敌人就会出现在屏幕上。我有一些方法可以让敌人按计划移动，所以我使用performSelector方法来调用另一个方法。

这是代码：

#import "RedEnemy.h"
@implementation RedEnemy
+(id)createRedEnemy{
return [[[self alloc]init]autorelease];
}
-(id)init{
if((self = [super init])){
CGSize size = [[CCDirector sharedDirector]winSize];
screenWidth = size.width;
screenHeight = size.height;
screenBounds = [[UIScreen mainScreen] bounds];
redEnemyFlameCounter = 1;
xPoint = screenWidth - 50;
yPoint = screenHeight - 50;
    randomNumberRedEnemy = arc4random() % 18;
    [self schedule:@selector(redEnemyFlight:)interval:randomNumberRedEnemy + 18/1.0f];
}
return self;
}
-(void)redEnemyFlight:(ccTime)delta{
redEnemy = [CCSprite spriteWithFile:@"redenemy.png"];
redEnemy.position = ccp(xPoint, yPoint);
[self addChild:redEnemy z:-1];
[self schedule:@selector(shootTheBullets:)interval:1.0f/2.0f];
CCMoveTo* redEnemyMoveDown  = [CCMoveTo actionWithDuration:3.0 position:ccp(xPoint, 70)];
CCMoveTo* redEnemyMoveUp = [CCMoveTo actionWithDuration:3.0 position:ccp(xPoint, yPoint -      60)];
CCSequence* redEnemyFloatingSequence = [CCSequence actions:redEnemyMoveDown, redEnemyMoveUp, nil];
CCRepeat* redEnemyFloatingRepeat = [CCRepeat actionWithAction:redEnemyFloatingSequence times:3];
[redEnemy runAction:redEnemyFloatingRepeat];
[self schedule: @selector(removeTheEnemy:)interval:18.0f/1.0f];
[self schedule: @selector(redEnemyFlame:)interval:1.0f/5.0f];
}
-(void)redEnemyFlame:(ccTime)delta{
redEnemyFlameCounter ++;
if (redEnemyFlameCounter % 2){
    [redEnemy setTexture:[[CCSprite spriteWithFile:@"redenemy2.png"]texture]];
}else{
    [redEnemy setTexture:[[CCSprite spriteWithFile:@"redenemy.png"]texture]];
}
}
-(void)removeTheEnemy:(ccTime)delta{
CCMoveBy* moveUp = [CCMoveBy actionWithDuration:0.5 position:ccp(70, 100)];
[redEnemy runAction:moveUp];
[self unschedule:@selector(removeTheEnemy:)];
[self performSelector:@selector(yellowEnemyFloating:) withObject:nil afterDelay:2.0f];
}
@end

这是最后一个代码片段所调用的。

#import "YellowEnemy.h"
@implementation YellowEnemy
+(id)createYellowEnemy{
return [[[self alloc]init]autorelease];
}
-(id)init{
if((self = [super init])){
    CGSize size = [[CCDirector sharedDirector]winSize];
    screenWidth = size.width;
    screenHeight = size.height;
    screenBounds = [[UIScreen mainScreen] bounds];
    yellowEnemyFlameCounter = 1;
    randomNumberYellowEnemy = arc4random() % 8;
    //[self schedule:@selector(yellowEnemyFloating:)interval:randomNumberYellowEnemy +       8 /1.0f];
}
return self;
}
-(void)yellowEnemyFloating:(ccTime)delta{
yellowEnemy = [CCSprite spriteWithFile:@"yellowenemy.png"];
yellowEnemy.position = ccp(screenWidth - 50, 50);
[self addChild:yellowEnemy z:-1];

yellowEnemyMoveDown  = [CCMoveTo actionWithDuration:2.0 position:ccp(yellowEnemy.position.x, 50)];
yellowEnemyMoveUp = [CCMoveTo actionWithDuration:2.0 position:ccp(yellowEnemy.position.x, screenHeight/2)];
yellowEnemyFloatingSequnece = [CCSequence actions:yellowEnemyMoveUp, yellowEnemyMoveDown, nil];
yellowEnemyFloatingRepeat = [CCRepeat actionWithAction:yellowEnemyFloatingSequnece times:2];
[yellowEnemy runAction:yellowEnemyFloatingRepeat];
[self schedule: @selector(yellowEnemyFlame:)interval:1.0f/5.0f];
}
-(void)yellowEnemyFlame:(ccTime)delta{
yellowEnemyFlameCounter ++;
if (yellowEnemyFlameCounter % 2){
    [yellowEnemy setTexture:[[CCSprite spriteWithFile:@"yellowenemy2.png"]texture]];
}else{
    [yellowEnemy setTexture:[[CCSprite spriteWithFile:@"yellowenemy.png"]texture]];
}
[self schedule:@selector(yellowEnemyFlight:)interval:8.0f/1.0f];
}
-(void)yellowEnemyFlight:(ccTime)delta{
yellowEnemyMoveLeft = [CCMoveTo actionWithDuration:4.0 position:ccp(-100, screenHeight/2)];
[yellowEnemy runAction:yellowEnemyMoveLeft];
[self performSelector:@selector(blueEnemyFlight:) withObject:nil afterDelay:2.0f];
}
@end

这就是最后一段代码所称的：

 #import "BlueEnemy.h"

 @implementation BlueEnemy
+(id)createBlueEnemy{
return [[[self alloc]init]autorelease];
}
-(id)init{
if ((self = [super init])) {
    CGSize size = [[CCDirector sharedDirector]winSize];
    screenWidth = size.width;
    screenHeight = size.height;
    screenBounds = [[UIScreen mainScreen] bounds];
    blueEnemyFlameCounter = 1;
    xPointBlueEnemy = screenWidth - 50;
    yPointBlueEnemy = screenHeight - 100;
    //randomNumberBlueEnemy = arc4random() % 18;
    //[self schedule:@selector(blueEnemyFlight:)interval:randomNumberBlueEnemy + 18/1.0f];
}
return self;
}
-(void)blueEnemyFlight:(ccTime)delta{
blueEnemy = [CCSprite spriteWithFile:@"blueenemy.png"];
blueEnemy.position = ccp(xPointBlueEnemy, yPointBlueEnemy);
[self addChild:blueEnemy z:-1];
CCMoveTo* blueEnemyMoveDown  = [CCMoveTo actionWithDuration:3.0 position:ccp(xPointBlueEnemy, 70)];
CCMoveTo* blueEnemyMoveUp = [CCMoveTo actionWithDuration:3.0 position:ccp(xPointBlueEnemy, yPointBlueEnemy - 60)];
CCSequence* blueEnemyFloatingSequence = [CCSequence actions:blueEnemyMoveDown, blueEnemyMoveUp, nil];
CCRepeat* blueEnemyFloatingRepeat = [CCRepeat actionWithAction:blueEnemyFloatingSequence times:3];
[blueEnemy runAction:blueEnemyFloatingRepeat];
[self schedule:@selector(shootTheWaterBullets:)interval:1.0f/2.0f];
[self schedule: @selector(blueEnemyFlame:)interval:1.0f/5.0f];
[self schedule: @selector(removeTheBlueEnemy:)interval:20.0f/1.0f];
}
-(void)blueEnemyFlame:(ccTime)delta{
blueEnemyFlameCounter ++;
if (blueEnemyFlameCounter % 2){
    [blueEnemy setTexture:[[CCSprite spriteWithFile:@"blueenemy2.png"]texture]];
}else{
    [blueEnemy setTexture:[[CCSprite spriteWithFile:@"blueenemy.png"]texture]];
}
}
-(void)removeTheBlueEnemy:(ccTime)delta{
CCMoveBy* moveUpBlueEnemy = [CCMoveBy actionWithDuration:0.5 position:ccp(70, 200)];
[blueEnemy runAction:moveUpBlueEnemy];
[blueEnemy removeChild:blueEnemy cleanup:YES];
[self unschedule:@selector(removeTheBlueEnemy:)];
[self performSelector:@selector(redEnemyFlight:) withObject:nil afterDelay:2.0f];
}
@end

Answer 1

原因是scheduleSelector和performSelect:的预期方法声明不同

// scheduleSelector sends a delta time (float)
-(void) method:(ccTime)delta;
// performSelector sends no parameters
-(void) method;
// performSelector:withObject: sends an id parameter
-(void) method:(id)object;

所以你不能做：

[self performSelector:@selector(redEnemyFlight:) withObject:nil afterDelay:2.0f];

因为要执行的方法具有错误的签名：

-(void)redEnemyFlight:(ccTime)delta;

在这种情况下，您应该使用scheduleSelector。此外，如果在BlueEnemy中运行上述performSelector代码，这将执行BlueEnemy对象（即self）中的选择器。要真正对红色敌人执行选择器，你必须参考红色敌人并执行：

[redEnemy performSelector: and so on ];

PS：避免在外部对象中调度选择器，而是向外部对象发送消息，并在该方法中启动调度。每个对象都应该管理自己的选择器。