iOS - iOS开发碎碎_ios 实现背景view碎屏效果-优快云博客

本文介绍iOS开发中屏幕截图的方法及图片处理技巧，包括如何保存屏幕图片到相册、图片合并及高斯模糊背景的实现等。此外还涉及计时器、状态栏颜色修改等实用知识点。

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保留两位小数运算

 float xxx = floorf(([middleMutableArray[0] floatValue] * 100)/100)/caloriePlanValue ;

修改状态栏颜色

[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault animated:YES];

计时器timer类一定要记得[timer invalidate];

timer = nil; 否则影响ViewController的释放

	//无法获取OpenGL的数据
        //屏幕截屏保存到沙盒self.view.frame.size
        //待添加一个按钮，保存当前屏幕图片到相册
        UIGraphicsBeginImageContext(CGSizeMake(self.view.frame.size.width, self.view.frame.size.height/2)); //currentView 当前的view
        [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
        UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        NSData *screenShotPNG = UIImagePNGRepresentation(viewImage);
        NSError *error = nil;
        [screenShotPNG writeToFile:[[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"share.png"] options:NSAtomicWrite error:&error];

截图

 UIView * snapView = [self.view snapshotViewAfterScreenUpdates:NO];

目前使用两张图合并的方法

-(void)saveImageFormView {
    //保存当前屏幕图片到相册
    //
    UIImage * mapImage = [mapView takeSnapshot];
    UIWindow *screenWindow = [[UIApplication sharedApplication] keyWindow];
    UIGraphicsBeginImageContextWithOptions(screenWindow.frame.size, NO, 0);
    [screenWindow.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    UIImageWriteToSavedPhotosAlbum([self addImage:image toImage:mapImage], nil, nil, nil);  //保存到相册中
}

//拼接图片
- (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2 {
    UIGraphicsBeginImageContextWithOptions(image1.size, NO, 0);
    // Draw image1
    [image1 drawInRect:CGRectMake(0, 0, image1.size.width, image1.size.height)];
    
    // Draw image2
    [image2 drawInRect:CGRectMake(0, self.mapContentView.frame.origin.y+64, image2.size.width, image2.size.height)];
    
    UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return resultingImage;
}

Images.xcassets中的素材

（1）只支持png格式的图片

（2）图片只支持[UIImage imageNamed]的方式实例化，但是不能从Bundle中加载

（3）在编译时，Images.xcassets中的所有文件会被打包为Assets.car的文件

时间戳转换成NSdate

 NSDate *confromTimesp = [NSDate dateWithTimeIntervalSince1970:[time intValue]];

设置NSdate 格式

    NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
    [formatter setDateStyle:NSDateFormatterMediumStyle];
    [formatter setTimeStyle:NSDateFormatterShortStyle];
    [formatter setDateFormat:@"HH:MM"];

将NSdate转换成formatter格式的String

[formatter stringFromDate:confromTimesp];

制作覆盖全屏的高斯模糊背景

通过使用UIWindow来使该View位于最上层

截取当前屏幕图片模糊化后设置为UIWindow的背景

    UIWindow *screenWindow = [[UIApplication sharedApplication] keyWindow];
    UIGraphicsBeginImageContextWithOptions(screenWindow.frame.size, NO, 0);
    [screenWindow.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    UIImage * blurimage = [UIImage imageByApplyingLightEffectToImage:image];

    blurWindow = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
    blurWindow.windowLevel = UIWindowLevelAlert;
    blurWindow.backgroundColor = [UIColor colorWithPatternImage:blurimage];
    blurWindow.hidden = NO;

杂项

NSString * string = [dictionary objectForKey:@"status"];
        if ([string isEqualToString:@"success"]) {
            handler(YES,string,nil);
        }else if ([string isEqualToString:@"failure"])
            handler(NO,string,[NSError errorWithDomain:[dictionary objectForKey:@"error"] code:-1 userInfo:nil]);

NSArray *array  = (NSArray *)responseObject;
        if (array) {
            NSMutableArray *result = [[NSMutableArray alloc] init];
            for (NSDictionary *object in array) {
                [result addObject:[self createFriendsArticlesCommentsModel:object]];
            }
            handler(YES,result,nil);
        } else {
            handler(NO,nil,[NSError errorWithDomain:@"error" code:-1 userInfo:nil]);
        }

failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        handler(NO,nil, error);}];

填充一个图片为View的背景

    self.texttableView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"FriendinTableViewBackground.png"]];