【移動(dòng)應(yīng)用開發(fā)技術(shù)】ios UITableView如何實(shí)現(xiàn)無數(shù)據(jù)加載占位圖片

【移動(dòng)應(yīng)用開發(fā)技術(shù)】iosUITableView如何實(shí)現(xiàn)無數(shù)據(jù)加載占位圖片

/upload/information/20200623/126/121367.gif+

(void)swizzleInstanceSelector:(SEL)originalSel

WithSwizzledSelector:(SEL)swizzledSel

{

Method

originMethod

=

class_getInstanceMethod(self,

originalSel);

Method

swizzedMehtod

=

class_getInstanceMethod(self,

swizzledSel);

BOOL

methodAdded

=

class_addMethod(self,

originalSel,

method_getImplementation(swizzedMehtod),

method_getTypeEncoding(swizzedMehtod));

if

(methodAdded)

{

class_replaceMethod(self,

swizzledSel,

method_getImplementation(originMethod),

method_getTypeEncoding(originMethod));

}else{

method_exchangeImplementations(originMethod,

swizzedMehtod);

}

}+

(void)load

{

static

dispatch_once_t

onceToken;

dispatch_once(&onceToken,

^{

[self

swizzleInstanceSelector:@selector(reloadData)

WithSwizzledSelector:@selector(kk_reloadData)];

});

}-

(void)kk_reloadData

{

[self

kk_checkEmpty];

[self

kk_reloadData];

}-

(void)kk_checkEmpty

{

BOOL

isEmpty

=

YES;

id<UITableViewDataSource>

src

=

self.dataSource;

NSInteger

sections

=

1;

if

([src

respondsToSelector:@selector(numberOfSectionsInTableView:)])

{

sections

=

[src

numberOfSectionsInTableView:self];

}

for

(int

i

=

0;

i

<

sections;

i++)

{

NSInteger

rows

=

[src

tableView:self

numberOfRowsInSection:i];

if

(rows)

{

isEmpty

=

NO;

}

}

if

(isEmpty)

{//數(shù)據(jù)為空，在這里添加視圖

}else{//數(shù)據(jù)不為空，在這里一處視圖

}

}@property

(nonatomic,

strong)

UIView

*placeHolderView;-

(void)setPlaceHolderView:(UIView

*)placeHolderView

{

objc_setAssociatedObject(self,

@selector(placeHolderView),

placeHolderView,

OBJC_ASSOCIATION_RETAIN_NONATOMIC);

}

-

(UIView

*)placeHolderView

{

return

objc_getAssociatedObject(self,

@selector(placeHolderView));

}if

(isEmpty)

{//數(shù)據(jù)為空，在這里添加視圖

}else{//數(shù)據(jù)不為空，在這里一處視圖

}if

(isEmpty)

{

[self.placeHolderView

removeFromSuperview];

[self

addSubview:self.placeHolderView];

}else{