block中为如何为全局变量赋值

Mr黄黄黄黄黄先森 2019-02-27 03:46:48



#import "WordTestViewController.h"

#import <BmobSDK/Bmob.h>

@interface WordTestViewController ()

@property (strong, nonatomic) IBOutlet UIView *testView;

@property (strong, nonatomic) NSArray *dataArray;



@end



@implementation WordTestViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    [self layoutUI];

//    self.dataArray = [self configDataWithClas:@"N4"];

    [self configDataWithClas:@"N4"];

    NSLog(@"self.dataArray:%@",self.dataArray);

}

-(void)layoutUI

{

    self.testView.layer.cornerRadius = 20;

    self.testView.layer.masksToBounds = YES;

}

-(void)configDataWithClas:(NSString *)class

{

    BmobQuery* query = [BmobQuery queryWithClassName:@"wordTest"];

    [query whereKey:@"class" equalTo:class];

    [query setLimit:10];

    NSMutableArray *mutalArray = [NSMutableArray new];

    [query findObjectsInBackgroundWithBlock:^(NSArray *array, NSError *error) {

        for (BmobObject *obj in array) {

            NSMutableDictionary *mutalDict = [[NSMutableDictionary alloc] init];

            [mutalDict setObject:[obj objectForKey:@"word"] forKey:@"word"];

            [mutalDict setObject:[obj objectForKey:@"TrueAns"] forKey:@"TrueAns"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns1"] forKey:@"fakeAns1"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns2"] forKey:@"fakeAns2"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns3"] forKey:@"fakeAns3"];

            [mutalArray addObject:mutalDict];

        }

        NSLog(@"Block中的mutalArray%@",mutalArray);

    }];

    NSLog(@"Block外的mutalArray%@",mutalArray);

    self.dataArray = mutalArray;

}

@end

使用bmob的SDK进行数据查询，返回之后的数组想赋值给self.dataArray，但是block这个数据结构还没弄清楚不知道怎么弄，在block中打印能看到数据，在block外打印就没是null



***********************Log信息****************************

2019-02-27 15:39:39.857261+0800 WordBank[5327:381131] Block外的mutalArray(

)

2019-02-27 15:39:39.857752+0800 WordBank[5327:381131] self.dataArray:(

)

2019-02-27 15:39:40.009077+0800 WordBank[5327:381131] Block中的mutalArray(

        {

        TrueAns = "\U6905\U5b50";

        fakeAns1 = "\U68b3\U5b50";

        fakeAns2 = "\U4e66\U5305";

        fakeAns3 = "\U684c\U5b50";

        word = "\U3044\U3059";

    },

        {

        TrueAns = "\U59b9\U59b9";

        fakeAns1 = "\U5f1f\U5f1f";

        fakeAns2 = "\U59d0\U59d0";

        fakeAns3 = "\U54e5\U54e5";

        word = "\U3044\U3082\U3046\U3068";

    },

        {

        TrueAns = "\U5927\U6d77";

        fakeAns1 = "\U866b\U5b50";

        fakeAns2 = "\U5c71";

        fakeAns3 = "\U9ca8\U9c7c";

        word = "\U3046\U307f";

    },

        {

        TrueAns = "\U4f46\U662f";

        fakeAns1 = "\U6240\U4ee5";

        fakeAns2 = "\U56e0\U4e3a";

        fakeAns3 = "\U53ef\U80fd";

        word = "\U3068\U3053\U308d\U304c";

    },

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Poco Carino 2019-03-01

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好厉害。好厉害

Mr黄黄黄黄黄先森 2019-03-01

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引用 29 楼 So灬低调的回复：

。。。。一般情况下他们说的方法都是可行了！要是还不行那就狠一点咯 while(1) { if(mutalArray.count!=0){ break; } }

我已经找到了一个可行的方法，就是在block中对数据进行持久化写入plist文件，然后用的时候再进行读取操作

So灬低调 2019-03-01

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。。。。一般情况下他们说的方法都是可行了！要是还不行那就狠一点咯 while(1) { if(mutalArray.count!=0){ break; } }

瓶邪.slj 2019-03-01

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引用 13 楼 Peter_Huang0623的回复:

引用 11 楼 So灬低调的回复：
其实都说的没错只是你这个循环中数据解析速度的问题，导致赋值的时候拿不准数据，有时候会有这也的问题！所以这种必须要立马得到数据，最好是做成同步block
就是这个赋值只有在viewdidload（）执行完之后才会赋上去，我在viewdididisappear或者viewwilldisappear中nslog可以看到结果，可是我对于UI的更新必须在viewdidiload中操作啊，我按照你上面的方法改了依旧block外为空

楼上说法同意，以前也朋友这样说

yewentao0823 2019-03-01

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学习学习学习学习

So灬低调 2019-03-01

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解决了就好！

So灬低调 2019-03-01

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引用 30 楼 Peter_Huang0623 的回复:

[quote=引用 29 楼 So灬低调的回复：]。。。。一般情况下他们说的方法都是可行了！要是还不行那就狠一点咯 while(1) { if(mutalArray.count!=0){ break; } }

我已经找到了一个可行的方法，就是在block中对数据进行持久化写入plist文件，然后用的时候再进行读取操作[/quote] 解析数据，存储数据入表，在读取数据，同样在block中需要更多的时间，在接下来打印数据依然还是同样的问题！如果解决了！可能是我们对你的需求不太了解

edondondon 2019-02-28

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把你的操作放到block中，如果需要确保在主线程中更新ui，使用dispatch_sync(dispatch_get_main_queue(),^{ //ui操作 });

楼下如果是妹子那就 2019-02-28

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在外面打印肯定没有数据，数据查询是异步操作，在外部打印时没有返回查询结果，用`Block`回调是在为了保证查询成功后，在进行`UI`赋值操作，把所有的`UI`都放到`Block`中执行即可：


[self configDataWithClas:@"N4" successBlock:^(NSArray *returnList) {
   
   // 在这里更新UI和赋值操作

 }];

Mr黄黄黄黄黄先森 2019-02-28

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引用 15 楼楼下如果是妹子那就的回复:

你把代码贴出来，打印的顺序不对。

[self configDataWithClas:@"" successBlock:^(NSArray *returnList) {



    }];

这个地方忘记传值了，但是现在不就是把数据从一个block放到了另一个block中吗？我在block外打印的self.dataArray还是为空啊



2019-02-28 10:45:51.395392+0800 WordBank[1230:201778] 

 self.dataArray:

(

)

2019-02-28 10:45:51.634465+0800 WordBank[1230:201778] ==============(

        {

        TrueAns = "\U6905\U5b50";

        fakeAns1 = "\U68b3\U5b50";

        fakeAns2 = "\U4e66\U5305";

        fakeAns3 = "\U684c\U5b50";

        word = "\U3044\U3059";

    },

        {

        TrueAns = "\U59b9\U59b9";

        fakeAns1 = "\U5f1f\U5f1f";

        fakeAns2 = "\U59d0\U59d0";

        fakeAns3 = "\U54e5\U54e5";

        word = "\U3044\U3082\U3046\U3068";

    },

        {

        TrueAns = "\U5927\U6d77";

        fakeAns1 = "\U866b\U5b50";

        fakeAns2 = "\U5c71";

        fakeAns3 = "\U9ca8\U9c7c";

        word = "\U3046\U307f";

    },

        {

        TrueAns = "\U4f46\U662f";

        fakeAns1 = "\U6240\U4ee5";

        fakeAns2 = "\U56e0\U4e3a";

        fakeAns3 = "\U53ef\U80fd";

        word = "\U3068\U3053\U308d\U304c";

    },

        {

        TrueAns = "\U5403\U996d";

        fakeAns1 = "\U4f11\U606f";

        fakeAns2 = "\U6563\U6b65";

        fakeAns3 = "\U5435\U67b6";

        word = "\U3084\U3059\U3080";

    },

        {

        TrueAns = "\U6628\U5929";

        fakeAns1 = "\U53bb\U5e74";

        fakeAns2 = "\U4eca\U5e74";

        fakeAns3 = "\U660e\U5929";

        word = "\U304d\U306e\U3046";

    },

        {

        TrueAns = "\U5fd8\U8bb0";

        fakeAns1 = "\U6d17";

        fakeAns2 = "\U5403\U996d";

        fakeAns3 = "\U7761\U89c9";

        word = "\U308f\U3059\U308c\U308b";

    },

        {

        TrueAns = "\U9c7c";

        fakeAns1 = "\U9a6c";

        fakeAns2 = "\U9752\U86d9";

        fakeAns3 = "\U91ce\U732a";

        word = "\U3055\U304b\U306a";

    },

        {

        TrueAns = "\U65b0\U7684";

        fakeAns1 = "\U53ef\U7231\U7684";

        fakeAns2 = "\U8d39\U52b2\U7684";

        fakeAns3 = "\U5435\U95f9\U7684";

        word = "\U3042\U305f\U3089\U3057\U3044";

    },

        {

        TrueAns = "\U5f00\U5fc3\U7684";

        fakeAns1 = "\U751f\U6c14\U7684";

        fakeAns2 = "\U60b2\U4f24\U7684";

        fakeAns3 = "\U9965\U997f\U7684";

        word = "\U3046\U308c\U3057\U3044";

    }

)

2019-02-28 10:45:51.640028+0800 WordBank[1230:201778] ==============(

        {

        TrueAns = "\U6905\U5b50";

        fakeAns1 = "\U68b3\U5b50";

        fakeAns2 = "\U4e66\U5305";

        fakeAns3 = "\U684c\U5b50";

        word = "\U3044\U3059";

    },

        {

        TrueAns = "\U59b9\U59b9";

        fakeAns1 = "\U5f1f\U5f1f";

        fakeAns2 = "\U59d0\U59d0";

        fakeAns3 = "\U54e5\U54e5";

        word = "\U3044\U3082\U3046\U3068";

    },

        {

        TrueAns = "\U5927\U6d77";

        fakeAns1 = "\U866b\U5b50";

        fakeAns2 = "\U5c71";

        fakeAns3 = "\U9ca8\U9c7c";

        word = "\U3046\U307f";

    },

        {

        TrueAns = "\U4f46\U662f";

        fakeAns1 = "\U6240\U4ee5";

        fakeAns2 = "\U56e0\U4e3a";

        fakeAns3 = "\U53ef\U80fd";

        word = "\U3068\U3053\U308d\U304c";

    },

        {

        TrueAns = "\U5403\U996d";

        fakeAns1 = "\U4f11\U606f";

        fakeAns2 = "\U6563\U6b65";

        fakeAns3 = "\U5435\U67b6";

        word = "\U3084\U3059\U3080";

    },

        {

        TrueAns = "\U6628\U5929";

        fakeAns1 = "\U53bb\U5e74";

        fakeAns2 = "\U4eca\U5e74";

        fakeAns3 = "\U660e\U5929";

        word = "\U304d\U306e\U3046";

    },

        {

        TrueAns = "\U5fd8\U8bb0";

        fakeAns1 = "\U6d17";

        fakeAns2 = "\U5403\U996d";

        fakeAns3 = "\U7761\U89c9";

        word = "\U308f\U3059\U308c\U308b";

    },

        {

        TrueAns = "\U9c7c";

        fakeAns1 = "\U9a6c";

        fakeAns2 = "\U9752\U86d9";

        fakeAns3 = "\U91ce\U732a";

        word = "\U3055\U304b\U306a";

    },

        {

        TrueAns = "\U65b0\U7684";

        fakeAns1 = "\U53ef\U7231\U7684";

        fakeAns2 = "\U8d39\U52b2\U7684";

        fakeAns3 = "\U5435\U95f9\U7684";

        word = "\U3042\U305f\U3089\U3057\U3044";

    },

        {

        TrueAns = "\U5f00\U5fc3\U7684";

        fakeAns1 = "\U751f\U6c14\U7684";

        fakeAns2 = "\U60b2\U4f24\U7684";

        fakeAns3 = "\U9965\U997f\U7684";

        word = "\U3046\U308c\U3057\U3044";

    }

)

Mr黄黄黄黄黄先森 2019-02-28

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引用 15 楼楼下如果是妹子那就的回复:

你把代码贴出来，打印的顺序不对。

//

//  WordTestViewController.m

//  WordBank

//

//  Created by Peter on 2019/2/27.

//  Copyright © 2019年 Hisen. All rights reserved.

//



#import "WordTestViewController.h"

#import <BmobSDK/Bmob.h>

#define RGBACOLOR(R,G,B,A)      [UIColor colorWithRed:R/255.0 green:G/255.0 blue:B/255.0 alpha:A]

@interface WordTestViewController ()

@property (strong, nonatomic) IBOutlet UIView *testView;

@property (strong, nonatomic) NSArray *dataArray;

@property (weak, nonatomic) IBOutlet UILabel *wordLabel;

@property (weak, nonatomic) IBOutlet UILabel *choiceA;

@property (weak, nonatomic) IBOutlet UILabel *choiceB;

@property (weak, nonatomic) IBOutlet UILabel *choiceC;

@property (weak, nonatomic) IBOutlet UILabel *choiceD;



@end



@implementation WordTestViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    [self layoutUI];

    __weak typeof (self) weakSelf = self;

    [self configDataWithClas:@"" successBlock:^(NSArray *returnList) {

        

        weakSelf.dataArray = returnList;

        NSLog(@"==============%@",returnList);

        NSLog(@"==============%@",weakSelf.dataArray);

//        [weakSelf.tableView reloadData];

    }];

    NSLog(@"\n self.dataArray:\n%@",self.dataArray);

}

-(NSArray *)dataArray

{

    if (_dataArray == nil) {

        _dataArray = [NSArray array];

    }

    return _dataArray;

}



-(void)layoutUI

{

    self.testView.layer.cornerRadius = 20;

    self.testView.layer.shadowOffset = CGSizeMake(0, 2.5);

    self.testView.layer.shadowOpacity = 0.3;

    self.testView.layer.shadowColor = RGBACOLOR(0, 0, 0, 1).CGColor;

}

//-(void)configDataWithClas:(NSString *)class

//{

//    BmobQuery* query = [BmobQuery queryWithClassName:@"wordTest"];

//    [query whereKey:@"class" equalTo:class];

//    [query setLimit:10];

//    __block NSMutableArray *mutalArray = [NSMutableArray array];

//    __weak typeof(self) weakSelf = self;

//    [query findObjectsInBackgroundWithBlock:^(NSArray *array, NSError *error) {

//        for (BmobObject *obj in array) {

//            NSMutableDictionary *mutalDict = [[NSMutableDictionary alloc] init];

//            [mutalDict setObject:[obj objectForKey:@"word"] forKey:@"word"];

//            [mutalDict setObject:[obj objectForKey:@"TrueAns"] forKey:@"TrueAns"];

//            [mutalDict setObject:[obj objectForKey:@"fakeAns1"] forKey:@"fakeAns1"];

//            [mutalDict setObject:[obj objectForKey:@"fakeAns2"] forKey:@"fakeAns2"];

//            [mutalDict setObject:[obj objectForKey:@"fakeAns3"] forKey:@"fakeAns3"];

//            [mutalArray addObject:mutalDict];

//        }

//        weakSelf.dataArray = [mutalArray copy];

//        NSLog(@"\n block内部的mutalArray:\n %@",mutalArray);

//    }];

//    NSLog(@"\n block外部的mutalArray:\n %@",mutalArray);

//}



-(void)configDataWithClas:(NSString *)class successBlock:(void (^)(NSArray *returnList))successBlock

{

    BmobQuery* query = [BmobQuery queryWithClassName:@"wordTest"];

    [query whereKey:@"class" equalTo:class];

    [query setLimit:10];

    __block NSMutableArray *mutalArray = [NSMutableArray array];

//    __weak typeof(self) weakSelf = self;

    [query findObjectsInBackgroundWithBlock:^(NSArray *array, NSError *error) {

        for (BmobObject *obj in array) {

            NSMutableDictionary *mutalDict = [[NSMutableDictionary alloc] init];

            [mutalDict setObject:[obj objectForKey:@"word"] forKey:@"word"];

            [mutalDict setObject:[obj objectForKey:@"TrueAns"] forKey:@"TrueAns"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns1"] forKey:@"fakeAns1"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns2"] forKey:@"fakeAns2"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns3"] forKey:@"fakeAns3"];

            [mutalArray addObject:mutalDict];

        }

        

        if(successBlock){

            successBlock([mutalArray copy]);

        }

    }];

}









-(void)didClickChoiceLabel:(NSString *)choiceText

{

    

}

@end

楼下如果是妹子那就 2019-02-28

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你把代码贴出来，打印的顺序不对。

Mr黄黄黄黄黄先森 2019-02-28

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[quote=引用 12 楼楼下如果是妹子那就的回复:]



-(void)configDataWithClas:(NSString *)class successBlock:(void (^)(NSArray *returnList))successBlock

{

    BmobQuery* query = [BmobQuery queryWithClassName:@"wordTest"];

    [query whereKey:@"class" equalTo:class];

    [query setLimit:10];

    __block NSMutableArray *mutalArray = [NSMutableArray array];

    __weak typeof(self) weakSelf = self;

    [query findObjectsInBackgroundWithBlock:^(NSArray *array, NSError *error) {

        for (BmobObject *obj in array) {

            NSMutableDictionary *mutalDict = [[NSMutableDictionary alloc] init];

            [mutalDict setObject:[obj objectForKey:@"word"] forKey:@"word"];

            [mutalDict setObject:[obj objectForKey:@"TrueAns"] forKey:@"TrueAns"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns1"] forKey:@"fakeAns1"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns2"] forKey:@"fakeAns2"];

            [mutalDict setObject:[obj objectForKey:@"fakeAns3"] forKey:@"fakeAns3"];

            [mutalArray addObject:mutalDict];

        }



        if(successBlock){

            successBlock([mutalArray copy]);

        }

    }];

}



- (void)viewDidLoad {

    [super viewDidLoad];

__weak typeof (self) weakSelf = self;

 [self configDataWithClas:@"" successBlock:^(NSArray *returnList) {

       

        weakSelf.dataArray = returnList;

        NSLog(@"==============%@",returnList);

        NSLog(@"==============%@",weakSelf.dataArray);

        [weakSelf.tableView reloadData];

    }];

}

[/quote



2019-02-28 10:27:47.277913+0800 WordBank[1213:198371] 

 self.dataArray:

(

)

2019-02-28 10:27:47.402890+0800 WordBank[1213:198371] ==============(

)

2019-02-28 10:27:47.402964+0800 WordBank[1213:198371] ==============(

)

Mr黄黄黄黄黄先森 2019-02-28

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引用 11 楼 So灬低调的回复：

其实都说的没错只是你这个循环中数据解析速度的问题，导致赋值的时候拿不准数据，有时候会有这也的问题！所以这种必须要立马得到数据，最好是做成同步block

就是这个赋值只有在viewdidload（）执行完之后才会赋上去，我在viewdididisappear或者viewwilldisappear中nslog可以看到结果，可是我对于UI的更新必须在viewdidiload中操作啊，我按照你上面的方法改了依旧block外为空

楼下如果是妹子那就 2019-02-28

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-(void)configDataWithClas:(NSString *)class successBlock:(void (^)(NSArray *returnList))successBlock
{
    BmobQuery* query = [BmobQuery queryWithClassName:@"wordTest"];
    [query whereKey:@"class" equalTo:class];
    [query setLimit:10];
    __block NSMutableArray *mutalArray = [NSMutableArray array];
    __weak typeof(self) weakSelf = self;
    [query findObjectsInBackgroundWithBlock:^(NSArray *array, NSError *error) {
        for (BmobObject *obj in array) {
            NSMutableDictionary *mutalDict = [[NSMutableDictionary alloc] init];
            [mutalDict setObject:[obj objectForKey:@"word"] forKey:@"word"];
            [mutalDict setObject:[obj objectForKey:@"TrueAns"] forKey:@"TrueAns"];
            [mutalDict setObject:[obj objectForKey:@"fakeAns1"] forKey:@"fakeAns1"];
            [mutalDict setObject:[obj objectForKey:@"fakeAns2"] forKey:@"fakeAns2"];
            [mutalDict setObject:[obj objectForKey:@"fakeAns3"] forKey:@"fakeAns3"];
            [mutalArray addObject:mutalDict];
        }

        if(successBlock){
            successBlock([mutalArray copy]);
        }
    }];
}


- (void)viewDidLoad {
    [super viewDidLoad];
__weak typeof (self) weakSelf = self;
 [self configDataWithClas:@"" successBlock:^(NSArray *returnList) {
       
        weakSelf.dataArray = returnList;
        NSLog(@"==============%@",returnList);
        NSLog(@"==============%@",weakSelf.dataArray);
        [weakSelf.tableView reloadData];
    }];
}

So灬低调 2019-02-28

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其实都说的没错只是你这个循环中数据解析速度的问题，导致赋值的时候拿不准数据，有时候会有这也的问题！所以这种必须要立马得到数据，最好是做成同步block

So灬低调 2019-02-28

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mutalArray不用加修饰也没关系，都不行的话就强制使用同步转换 NSOperationQueue *queue = [NSOperationQueue mainQueue]; [queue addOperationWithBlock:^{ myAsyncBlock(xxxx) }];

hua397 2019-02-28

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解决方法： NSMutableArray *mutalArray = [NSMutableArray new]; 把它改成 self.dataArray = [NSMutableArray new]; 同时，block内部用 [self.dataArray addObject:xxx]; 原因： 1. findObjectsInBackgroundWithBlock是一个异步操作，它会把task追加下一次runloop执行，你可以简单理解为block外的代码会被先执行，block内的代码晚一点才执行，所以block外先打印是个空数组，然后block才打印

Mr黄黄黄黄黄先森 2019-02-28

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引用 18 楼楼下如果是妹子那就的回复：

在外面打印肯定没有数据，数据查询是异步操作，在外部打印时没有返回查询结果，用`Block`回调是在为了保证查询成功后，在进行`UI`赋值操作，把所有的`UI`都放到`Block`中执行即可：
[self configDataWithClas:@"N4" successBlock:^(NSArray *returnList) {
   
   // 在这里更新UI和赋值操作

 }];

那我每更新一次岂不是就要调用这个block一次，我其实是做一个词汇量测试的功能，我想着一次性把数据加载完然后后面我还有很多事件来控制UI的更新，如果每次都要调用block来更新那很麻烦

Mr黄黄黄黄黄先森 2019-02-28