我想测试块函数和上下文的值。测试代码为:
//xxx.h
@interface textObj : NSObject
@property (nonatomic, retain) NSNumber * num;
@end
typedef void (^ returnHandle)(NSNumber * res);
@interface BlockTest : NSObject
- (void) textBlock:(textObj *)num completionHandler:(void (^)(NSNumber * res))handler;
@end
//xxx.m
@implementation textObj
@synthesize num;
@end
@interface BlockTest (){
returnHandle rt;
}
- (void)toggleChromeDisplay;
@end
@implementation BlockTest
- (void) dealloc{
Block_release(rt);
[super dealloc];
}
- (void)toggleChromeDisplay
{
NSNumber *ret = [NSNumber numberWithInt:111];
rt(ret);
}
void (^handle)(NSNumber * res, NSError *error);
- (void) textBlock:(textObj *)g1 completionHandler:(void (^)(NSNumber * res))handler
{
rt = Block_copy(handler);
[self performSelector:@selector(toggleChromeDisplay) withObject:nil afterDelay:0.5];
return;
}
@end
测试示例调用代码是:
//first sample code...
- (void)viewDidLoad
{
[super viewDidLoad];
test = [[BlockTest alloc]init];
textObj * g1;
g1 = [[textObj alloc] init];
[g1 setNum:[NSNumber numberWithInt:10]];
NSLog(@"main 0 g1 num=%@ count=%d", [g1 num], [g1 retainCount]);
[test textBlock:g1 completionHandler:^(NSNumber *res) {
NSLog(@"value=%@", [g1 num]);
[g1 setNum:[NSNumber numberWithInt:20]];
NSLog(@"main 1 g1 num=%@ count=%d", [g1 num], [g1 retainCount]);
} ];
NSLog(@"main 2 g1 num=%@ count=%d", [g1 num], [g1 retainCount]);
[g1 release];
NSLog(@"main 3 g1 num=%@ count=%d", [g1 num], [g1 retainCount]);
}
在块功能中,我可以更改 g1 值。没关系。但是当我将 g1 声明为测试的公共值时,它会在块函数中出错。g1 无法访问。它输出 EXC_BAD_ACCESS(code=2, address=0x26) 错误。
//second sample code...
@interface UIMainViewController (){
@public
textObj * g1;
}
@end
- (void)viewDidLoad
{
[super viewDidLoad];
test = [[BlockTest alloc]init];
//textObj * g1;
g1 = [[textObj alloc] init];
[g1 setNum:[NSNumber numberWithInt:10]];
NSLog(@"main 0 g1 num=%@ count=%d", [g1 num], [g1 retainCount]);
[test textBlock:g1 completionHandler:^(NSNumber *res) {
NSLog(@"value=%@", [g1 num]);
[g1 setNum:[NSNumber numberWithInt:20]];
NSLog(@"main 1 g1 num=%@ count=%d", [g1 num], [g1 retainCount]);
} ];
NSLog(@"main 2 g1 num=%@ count=%d", [g1 num], [g1 retainCount]);
[g1 release];
NSLog(@"main 3 g1 num=%@ count=%d", [g1 num], [g1 retainCount]);
}
我混淆了两个不同的示例代码,为什么第二个测试代码会遇到崩溃?