尝试对我的导航栏按钮设置正确的UIBarButtonSystemItem进行单元测试。
我可以找回样式,但似乎找不到找到UIBarButtonSystemItem的方法
为按钮设置的枚举。此操作失败,因为样式不同于
UIBarButtonSystemItem:
- (void)test_init_should_set_left_right_barButtonItems {
UIBarButtonItem *left = mainVCSUT.navigationItem.leftBarButtonItem;
UIBarButtonItem *right = mainVCSUT.navigationItem.rightBarButtonItem;
[Assert isNotNil:left];
[Assert isNotNil:right];
UIBarButtonItemStyle leftStyle = left.style;
UIBarButtonItemStyle rightStyle = right.style;
[Assert that:[The int:leftStyle] is:[Equal to:[The int:UIBarButtonSystemItemRefresh]]];
[Assert that:[The int:rightStyle] is:[Equal to:[The int:UIBarButtonSystemItemSearch]]];
}
最佳答案
至少在iOS 6.1上(我尚未测试其他版本),UIBarButtonItem
具有未声明的方法systemItem
,该方法返回传递给初始化程序的值。您可以使用键值编码轻松访问它:
UIBarButtonSystemItem systemItemIn = UIBarButtonSystemItemAdd;
UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:systemItemIn target:nil action:NULL];
NSNumber *value = [item valueForKey:@"systemItem"];
UIBarButtonSystemItem systemItemOut = [value integerValue];
NSLog(@"systemItemIn = %d, systemItemOut = %d", systemItemIn, systemItemOut);
如果那不起作用,则可以为内部匿名结构创建一个typedef,该结构是
UIBarButtonItem
类的实例变量,用于存储此信息,并使用私有(private)ivar的名称和Objective C运行时,如下所示://Copied from UIBarButtonItem.h, this is the struct used for the _barButtomItemFlags ivar
typedef struct {
unsigned int enabled:1;
unsigned int style:3;
unsigned int isSystemItem:1;
unsigned int systemItem:7;
unsigned int viewIsCustom:1;
unsigned int isMinibarView:1;
unsigned int disableAutosizing:1;
unsigned int selected:1;
unsigned int imageHasEffects:1;
} FlagsStruct;
// In our test code
// Instantiate a bar button item
UIBarButtonSystemItem systemItemIn = UIBarButtonSystemItemAdd;
UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:systemItemIn target:nil action:NULL];
// Set up variables needed for run time functions
Class barItemClass = [item class];
BOOL foundIt = NO; // We check this flag to make sure we found the ivar we were looking for
ptrdiff_t ivarOffset = 0; // This will be the offset of _barButtomItemFlags within the bar button item object
// Iterate through all of UIBarButtonItem's instance variables
unsigned int ivarCount = 0;
Ivar *ivarList = class_copyIvarList(barItemClass, &ivarCount);
for (int i = 0; i < ivarCount; i++) {
Ivar ivar = ivarList[i];
const char *ivarName = ivar_getName(ivar);
if (!strcmp(ivarName, "_barButtonItemFlags")) {
// We've found an ivar matching the name. We'll get the offset and break from the loop
foundIt = YES;
ivarOffset = ivar_getOffset(ivar);
break;
}
}
free(ivarList);
if (foundIt) {
// Do a little pointer math to get the FlagsStruct - this struct contains the system item value.
void *itemPointer = (__bridge void *)item;
FlagsStruct *flags = itemPointer + ivarOffset;
UIBarButtonSystemItem systemItemOut = flags->systemItem;
NSLog(@"systemItemIn = %d, systemItemOut = %d", systemItemIn, systemItemOut);
BOOL equal = (systemItemIn == systemItemOut);
if (equal) {
NSLog(@"yes they are equal");
}
else {
NSLog(@"no they are not");
}
}
else {
// Perhaps Apple changed the ivar name?
NSLog(@"didn't find any such ivar :(");
}
无论采用哪种方法,它都有可能改变,因此我建议您仅在经过验证以支持这两种方法的OS版本上有条件地运行测试。
关于iphone - 从UIBarButtonItem取回UIBarButtonSystemItem,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/15603375/