三种内存释放模式
1.如果是用属性并且retian了
self.labelUp=[[[UILabelalloc]initWithFrame:CGRectMake(15,
frame.size.height/3-11, frame.size.width-15-10,22)]autorelease];
self.labelUp=nil;
2.如果只是一般的成员变量
lbl = [[UILabelalloc]init];
NSLog(@"",[lblretainCount]);
[selfaddSubview:lbl];
[lblrelease];
3。直接声明成自动释放变量
lbl = [[[UILabelalloc]init]autorelease];
[selfaddSubview:lbl];