问如何检查cocoa中以编程方式创建的NSCheckbox的状态

EN

for(int i=1; i<=number;i++)
{
    DeleteCheckbox = [[NSButton alloc] initWithFrame:NSMakeRect (20,textfield_Y,50,25)];
    [DeleteCheckbox setButtonType:NSSwitchButton];
    [DeleteCheckbox setBezelStyle:0];
    [DeleteCheckbox setTitle:@""];
    [DeleteCheckbox setTag:200+i];
    [DeleteCheckbox setState:NSOffState];
    [DeleteCheckbox setAction:@selector(checkState:)];
    [guiView addSubview:DeleteCheckbox];
    [DeleteCheckbox release];
}

-(IBAction)checkState:(id)sender
{
    if ([DeleteCheckbox state] == NSOnState) {

        NSLog(@"selected");
    }
    else {

        NSLog(@"not selected");

    }
}