IOS 自定义加载框

客户端请求网络，分两种方式，同步和异步。同步请求一般不推荐，一般都用异步请求。

IOS自带的访问网络过程中在状态栏wifi右边会有一个转圈的框会提示用户正在请求网络，但是在设计App的时候，我们对应网络请求会自定义一个网络加载框提示用户正在从服务器获取数据，这样做可以增强用户体验。

///自定义加载框
@interface LoadingView : UIView
{
    ///指示器
    UIActivityIndicatorView *indicatorView;
    ///包含指示器和文字的view
    UIView *conerView;
}
///是否是模拟同步
@property (nonatomic) BOOL isLikeSynchro;

///显示加载框
- (void)show;

///关闭加载框
- (void)close;

///获取LoadingView单例,isLikeSynchro  Yes:类似同步，通过遮盖整个窗体实现 No:异步
+ (LoadingView *)shareLoadingView;
@end

#import "LoadingView.h"
#import <QuartzCore/QuartzCore.h>

@implementation LoadingView

static LoadingView *mLoadingView = nil;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
}
*/


///初始化加载框，这个函数是表示LoadingView的大小，如果是Yes，则loadView的大小为整个窗体，在这种情况下网络请求的时候会遮盖整个窗体，用户其他操作都是无效的相当于同步，如果是No，则loadView的大小为为150*80，用户的其他操作是有效的，这种情况相下需要保证loadingView唯一；
- (id)initIsLikeSynchro:(BOOL)isLikeSynchro{
    if (isLikeSynchro) {
        self = [super initWithFrame:[UIApplication sharedApplication].keyWindow.bounds];
    }else{
        self = [super initWithFrame:CGRectMake((320-150)/2, ([UIApplication sharedApplication].keyWindow.bounds.size.height-80)/2, 150, 80)];
    }
    
    if (self) {
        self.isLikeSynchro = isLikeSynchro;
        self.userInteractionEnabled = YES;
        self.backgroundColor = [UIColor clearColor];
        
        conerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 150, 80)];

        [self setCenter:conerView withParentRect:self.frame];
        UIColor *color = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.65];
        conerView.backgroundColor = color;
        [self addSubview:conerView];
        
        indicatorView = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(50, 0, 50, 50)];
        [conerView addSubview:indicatorView];
        [indicatorView startAnimating];
        
        UILabel *lblTitle = [[UILabel alloc] initWithFrame:CGRectMake(0, 40, 150, 40)];
        lblTitle.backgroundColor = [UIColor clearColor];
        lblTitle.textColor = [UIColor whiteColor];
        lblTitle.textAlignment = NSTextAlignmentCenter;
        lblTitle.text = @"正在努力加载中...";
        lblTitle.font = [UIFont systemFontOfSize:14];
        [conerView addSubview:lblTitle];
        
        conerView.layer.cornerRadius = 8;
        conerView.layer.masksToBounds = YES;
    }
    return self;
}

- (void)show{
    if ([UIApplication sharedApplication].keyWindow.rootViewController.navigationController) {
        [[UIApplication sharedApplication].keyWindow.rootViewController.navigationController.view addSubview:self];
    }else{
        [[UIApplication sharedApplication].keyWindow addSubview:self];
    }
}

- (void)close{
    [self removeFromSuperview];
}

+ (LoadingView *)shareLoadingView{
    @synchronized(self){
        if (mLoadingView==nil) {
            mLoadingView = [[self alloc] initIsLikeSynchro:NO];
        }
    }
    return mLoadingView;
}

+ (id)allocWithZone:(NSZone *)zone{
    @synchronized(self){
        if (mLoadingView==nil) {
            mLoadingView = [super allocWithZone:zone];
            return mLoadingView;
        }
    }
    return  nil;
}

///设置子View在父View中居中
- (void)setCenter:(UIView *)child withParentRect:(CGRect)parentRect{
    CGRect rect = child.frame;
    rect.origin.x = (parentRect.size.width - child.frame.size.width)/2;
    rect.origin.y = (parentRect.size.height - child.frame.size.height)/2;
    child.frame = rect;
}

使用的时候 只需要调用

[[LoadingView shareLoadingView] show];

[[LoadingView shareLoadingView] close];

转载于:https://my.oschina.net/simple2012/blog/157828