第十六篇、MBprogressHUD的使用和获取当前的控制器

简介：

　　在开发应用的时候，为了更好的增加用户的体验，常常在客户端向服务端请求数据的时候，在适当的地方加上非模态HUD,让用户可以可以知道当前的进度，稍作等待。

　　

MBProgressHUD 第三方框架Github地址

#import "AppDelegate+HUD.h"
#import "MBProgressHUD.h"

@implementation AppDelegate (HUD)

// 获取当前处于activity状态的view controller （常用于收到异地登录，退出登录的弹窗）
- (UIViewController *)activityViewController
{
    UIViewController* activityViewController = nil;

    UIWindow *window = [[UIApplication sharedApplication] keyWindow];

    // 如果是模态控制器用这个方法获取
    UIViewController *appRootVC = window.rootViewController;
    UIViewController *topVC = appRootVC;
    if (topVC.presentedViewController) {
        topVC = topVC.presentedViewController;
        return topVC;
    }

    if(window.windowLevel != UIWindowLevelNormal)
    {
        NSArray *windows = [[UIApplication sharedApplication] windows];
        for(UIWindow *tmpWin in windows)
        {
            if(tmpWin.windowLevel == UIWindowLevelNormal)
            {
                window = tmpWin;
                break;
            }
        }
    }

    NSArray *viewsArray = [window subviews];
    if([viewsArray count] > )
    {
        UIView *frontView = [viewsArray objectAtIndex:];

        id nextResponder = [frontView nextResponder];

        if([nextResponder isKindOfClass:[UIViewController class]])
        {
            activityViewController = nextResponder;
        }
        else
        {
            activityViewController = window.rootViewController;
        }
    }

    return activityViewController;
}

/**
 * 因为网络请求是在异步线程中执行，只有主线程才可以更新UI
 */
// 显示加载
- (void) showHUD:(NSString *)msg
{
    dispatch_async(dispatch_get_main_queue(), ^{
        if ([self.window viewWithTag:]) {
            [[self.window viewWithTag:] removeFromSuperview];
        }
        MBProgressHUD *HUD = [[MBProgressHUD alloc] initWithView:self.window];
        HUD.tag = ;
        [self.window addSubview:HUD];
        HUD.label.text = msg;
        HUD.contentColor = [UIColor blackColor];
        HUD.label.textColor = [UIColor colorWithRed:254.0/ green:71.0/ blue:67.0/ alpha:];
        [HUD setUserInteractionEnabled:NO]; // 设置成非模态显示
        [HUD showAnimated:YES];
    });

}

// 移除
- (void) removeHUD
{
    dispatch_async(dispatch_get_main_queue(), ^{
        [[self.window viewWithTag:] hideAnimated:YES];
        [[self.window viewWithTag:] removeFromSuperViewOnHide];
    });

}

// 显示信息
- (void) showMessage:(NSString *) msg
{

    dispatch_async(dispatch_get_main_queue(), ^{
        [[self.window viewWithTag:] hideAnimated:YES];
        [[self.window viewWithTag:] removeFromSuperViewOnHide];

        MBProgressHUD *HUDText = [MBProgressHUD showHUDAddedTo:self.window animated:YES];
        // 设置只是显示文本
        HUDText.tag = ;
        HUDText.mode = MBProgressHUDModeText;
        HUDText.label.text = msg;
        HUDText.margin = 10.0f;
        //    CGPoint currentOffset = HUDText.offset;
        //    currentOffset.y = -[UIScreen mainScreen].bounds.size.height / 2 + 80; // 设置Y的起始位置
        //    HUDText.offset = currentOffset;
        HUDText.removeFromSuperViewOnHide = YES;
        [HUDText setUserInteractionEnabled:NO];
        [HUDText hideAnimated:YES afterDelay:2.8];
    });
}