IOS开发基础知识--碎片11

1:AFNetwork判断网络状态

#import “AFNetworkActivityIndicatorManager.h"

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    //网络
    [[AFNetworkActivityIndicatorManager sharedManager] setEnabled:YES];
    [[AFNetworkReachabilityManager sharedManager] startMonitoring];
    //网络状态判断
    [[AFNetworkReachabilityManager sharedManager] setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        switch (status) {
            case AFNetworkReachabilityStatusNotReachable:{
                [self showMBPHudTipStr:@"当前无网络连接"];
                break;
            }
            case AFNetworkReachabilityStatusReachableViaWiFi:{
                [LogUtil logUtilstring:@"WiFi网络"];
                break;
            }
            case AFNetworkReachabilityStatusReachableViaWWAN:{
                [self showMBPHudTipStr:@"无线网络"];
                break;
            }
            default:
                break;
        }
    }];

    return YES;
}

2:UIButton倒计时

当在倒计时uibutton不能被响应事件；

-(void)startTime{
    __block int timeout=; //倒计时时间
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, );
    dispatch_source_t _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, , ,queue);
    dispatch_source_set_timer(_timer,dispatch_walltime(NULL, ),1.0*NSEC_PER_SEC, ); //每秒执行
    dispatch_source_set_event_handler(_timer, ^{
        if(timeout<=){ //倒计时结束，关闭
            dispatch_source_cancel(_timer);
            dispatch_async(dispatch_get_main_queue(), ^{
                //设置界面的按钮显示 根据自己需求设置
                [self.againBtn setTitle:@"重发验证码" forState:UIControlStateNormal];
                self.againBtn.userInteractionEnabled = YES;
                self.labNoMessage.text=@"没有收到验证码吗？";
                self.labNoMessage.textColor=[UIColor redColor];
            });
        }else{
            int seconds = timeout % ;
            NSString *strTime = [NSString stringWithFormat:@"%.2d", seconds];
            dispatch_async(dispatch_get_main_queue(), ^{
                //设置界面的按钮显示 根据自己需求设置
                [self.againBtn setTitle:[NSString stringWithFormat:@"重发激活邮件(%@)",strTime] forState:UIControlStateNormal];
                self.againBtn.userInteractionEnabled = NO;
                self.labNoMessage.text=@"激活邮件发送成功";
                self.labNoMessage.textColor=[UIColor colorWithHexString:@"84BF20"];

            });
            timeout--;

        }
    });
    dispatch_resume(_timer);

}

3:判断iphone设备

#define IS_IPAD (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
#define IS_IPHONE (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
#define IS_RETINA ([[UIScreen mainScreen] scale] >= 2.0)

#define SCREEN_WIDTH ([[UIScreen mainScreen] bounds].size.width)
#define SCREEN_HEIGHT ([[UIScreen mainScreen] bounds].size.height)
#define SCREEN_MAX_LENGTH (MAX(SCREEN_WIDTH, SCREEN_HEIGHT))
#define SCREEN_MIN_LENGTH (MIN(SCREEN_WIDTH, SCREEN_HEIGHT))

#define IS_IPHONE_4_OR_LESS (IS_IPHONE && SCREEN_MAX_LENGTH < 568.0)
#define IS_IPHONE_5 (IS_IPHONE && SCREEN_MAX_LENGTH == 568.0)
#define IS_IPHONE_6 (IS_IPHONE && SCREEN_MAX_LENGTH == 667.0)
#define IS_IPHONE_6P (IS_IPHONE && SCREEN_MAX_LENGTH == 736.0)

4:在IOS8以下报一个自动布局的BUG,而在IOS8却能正常运行

会导致APP挂掉,BUG内容:
Terminating app due to uncaught exception ‘NSInternalInconsistencyException’, reason: ‘Auto Layout still required after executing -layoutSubviews.
 UITableView’s implementation of -layoutSubviews needs to call super.’

- (void)layoutSubviews
{
    //自动布局的内容放在super layoutSubviews前面
    [self _updateConstraints];

    [super layoutSubviews];
}

5:与JS交互,并把JS代码兼容android跟IOS

JS代码:

$(function () {
    var u = navigator.userAgent, app = navigator.appVersion;
    var isAndroid = u.indexOf('Android') > - || u.indexOf('Linux') > -; //android终端或者uc浏览器
    var isiOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/); //ios终端

    if (isAndroid) {
        $('#btn_Success').attr('href', 'javascript:mailActive.backHome()');
    }
    else if (isiOS) {
        $('#btn_Success').attr('href', 'protoclo://backHome');
    }
});

而IOS则是shouldStartLoadWithRequest:

-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    NSString *newURL=[[request URL] absoluteString];
    if([newURL hasPrefix:@"protoclo://"])
    {
        NSArray *stringArray=[newURL componentsSeparatedByString:@"//"];
        if (stringArray.count>&&[[stringArray objectAtIndex:] isEqualToString:@"backHome"]) {
            [self webJavascriptBackHome];
        }
    }
    return YES;
}

注:比较好IOS的JS交互第三方插件WebViewJavascriptBridge[不错的关于如何使用这个插件的说明：http://www.henishuo.com/webviewjavascriptbridge-detail-use/];在IOS开发调试内嵌webView时可以用Safari进行调试,它可以设置出开发模式菜单,开发->ios simulator 就可以实现查看网页的运行详情(Safari->偏好设置-高级-在菜单中显示“开发”);

如果IOS要调用JS的方法可以使用stringByEvaluatingJavaScriptFromString 如下实例

IOS代码：

- (IBAction)sdfsdfsdf:(id)sender {
[self.webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"getMessageFromApp('%@')", @"加载结束调sdfsdf用方法"]];
}

Html代码：

<script type="text/javascript">
function getMessageFromApp(message){
var testDiv = document.getElementById("testDiv");
testDiv.innerText = message;
}
</script>

6:FMDB使用的一点心得：数据库创建、制表、查询等以及image转换成二进制nsdata保存到数据库中

首先，获取数据库的路径，（如果不存在，就是我们想要存储的路径），不用担心每次都创建数据库会重复，不会的，如果没有则创建，有了就不会再重复创建；
接下来，我们要制表，首先我们先查看我们的表是否已经存在，方法在下面代码中；如果存在则跳过，不存在则创建

-(void)DataBaseInit
{
    //获取Document文件夹下的数据库文件，没有则创建
    NSString *dbPath = [self getDBPath];
    FMDatabase *membersDB = [FMDatabase databaseWithPath:dbPath];
    if (![membersDB open]) {
        NSLog(@"open membersDB failed");
        return;
    }  

    //监测数据库中我要需要的表是否已经存在
    NSString *existsSql = [NSString stringWithFormat:@"select count(name) as countNum from sqlite_master where type = 'table' and name = '%@'", @"Member" ];
    FMResultSet *rs = [membersDB executeQuery:existsSql];  

    if ([rs next]) {
        NSInteger count = [rs intForColumn:@"countNum"];
        NSLog(@"The table count: %li", count);
        if (count == ) {
            NSLog(@"log_keepers table is existed.");
            return;
        }  

        NSLog(@"log_keepers is not existed.");
        //创建表
        //[membersDB executeUpdate:@"CREATE TABLE PersonList (Name text, Age integer, Sex integer,Phone text, Address text, Photo blob)"];
        [membersDB executeUpdate:@"CREATE TABLE Member (Name text, Age integer, Sex integer,Height integer, Weight integer, Photo blob)"];
    }    

    [rs close];
}  

-(NSString *)getDBPath
{
    NSString *documentPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:];
    NSString *DBPath = [documentPath stringByAppendingPathComponent:@"members.db"];//成员列表数据库
    return DBPath;
}

下面是数据成员的添加，不过我首先检查数据库中我要建的成员是否已经存在，避免重复添加

-(void)doneAction:(UIButton *)button
{
    //保存到数据库 membersDB
    //获取Document文件夹下的数据库文件，没有则创建
    NSString *dbPath = [self getDBPath];
    FMDatabase *membersDB = [FMDatabase databaseWithPath:dbPath];
    if (![membersDB open]) {
        NSLog(@"open membersDB failed");
        return;
    }
    //返回数据库中第一条满足条件的结果
    //select count(name) as countNum from sqlite_master where type = 'table' and name = '%@'", @"log_keepers
    FMResultSet *rs =[membersDB executeQuery:@"SELECT COUNT(Name) AS countNum FROM Member WHERE Name = ?",self.nameTextField.text];
    while ([rs next]) {
        NSInteger count = [rs intForColumn:@"countNum"];
        NSLog(@"countNum == %i",count);
        if (count > ) {
         //   NSLog(@"你要创建的成员，已经创建同名的！");
//下面这个是我用的第三方库，用来提醒，很方便，不用，注释掉即可
 _noticeView = [[GCDiscreetNotificationView alloc]initWithText:@"成员已经保存 或者 同名成员已存在！" showActivity:YES inPresentationMode:GCDiscreetNotificationViewPresentationModeTop inView:self.view ];
            [_noticeView showAndDismissAutomaticallyAnimated];
        }
        else
        {
            //出入数据：刚健的成员添加进去
            //插入数据
            NSData *imageData = UIImagePNGRepresentation(self.iconImageView.image);//将png图片转化为nsdata  

            BOOL insert = [membersDB executeUpdate:@"INSERT INTO Member (Name, Age, Sex, Height, Weight, Photo) VALUES (?,?,?,?,?,?)",self.nameTextField.text,[NSNumber numberWithInteger:[self.ageTextField.text integerValue]],[NSNumber numberWithInteger:self.sex] ,[NSNumber numberWithInteger:[self.heightTextField.text integerValue]],[NSNumber numberWithInteger:[self.weightTextField.text integerValue]], imageData];  

            if (insert) {
                NSLog(@"添加成员成功！！");
            }
        }
    }  

    //关闭数据库
    [membersDB close];  

}