一，效果图。
二，工程图。
三，代码。
ViewController.h
#import <UIKit/UIKit.h> @interface ViewController : UIViewController
{
//loading
UIView *backViewLoad; }
@end
ViewController.m
#import "ViewController.h"
//loading
#import "IanAlert.h" @interface ViewController () @end @implementation ViewController - (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib. //loading
[self addLoadingView]; }
//点击任何处显示loading
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//loading
backViewLoad.hidden=NO;
[IanAlert showloading];
[self performSelector:@selector(loadStop) withObject:nil afterDelay:2.0];
}
//停止loading
-(void)loadStop
{
backViewLoad.hidden=YES;
[IanAlert hideLoading];
}
#pragma -mark --loading------
-(void)addLoadingView
{
backViewLoad=[[UIView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
backViewLoad.backgroundColor=[UIColor blackColor];
backViewLoad.alpha=0.8;
backViewLoad.hidden=YES;
[self.view addSubview:backViewLoad];
} - (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
} @end