解决后台正在数据请求时候,用户对界面操作引起的错误-加遮罩

//添加活动指示器背景图
-(void)addActivityBackgroundView{

if (activityOnView ==
nil) {
activityOnView = [[UIView
alloc]initWithFrame:[[UIScreen
mainScreen]bounds]];
activityOnView.backgroundColor = [UIColor
blackColor];
activityOnView.alpha =
0.1f;

[[[UIApplication
sharedApplication] keyWindow]
addSubview:activityOnView];
return;
}
if (![activityOnView
isDescendantOfView:[[UIApplication
sharedApplication] keyWindow]]) {
[[[UIApplication
sharedApplication] keyWindow]
addSubview:activityOnView];
}
}
//移除活动指示器背景图
-(void)removeActivityBackgroundView{
if (activityOnView) {
if ([activityOnView
isDescendantOfView:[[UIApplication
sharedApplication] keyWindow]]) {
[activityOnView
removeFromSuperview];
}
activityOnView=nil;
}
}