Ios 异步创建带有映像的数组数组

我需要下载矩阵中的图像（2d数组）列是数组，每个数组都由图像对象组成。问题是我需要异步下载所有这些图像。所以现在我有：

NSMutableArray *sideArray = [NSMutableArray arrayWithCapacity:columnCount];
for (int i = 0; i < columnCount; i++) {
    [sideArray addObject:[NSNull null]];
}

NSMutableArray *rowArray = [NSMutableArray arrayWithCapacity:rowCount];
for (int i = 0; i < rowCount; i++) {
    [rowArray addObject:[NSNull null]];
}

for (int columnIndex = 0; columnIndex < columnCount; columnIndex++) {
    for (int rowIndex = 0; rowIndex < rowCount; rowIndex++) {

        dispatch_group_enter(group);

        [NSURLConnection sendAsynchronousRequest: request queue: [NSOperationQueue mainQueue] completionHandler:
         ^(NSURLResponse *response, NSData *data, NSError *connectionError)
         {
             if (data.length && nil == connectionError)
             {
                 UIImage *image = [UIImage imageWithData:data];
                 [rowArray replaceObjectAtIndex:rowIndex withObject:image];
             }
             dispatch_group_leave(group);
         }];
    }
    [sideArray replaceObjectAtIndex:columnIndex withObject:rowArray];
}

NSMutableArray*sideArray=[NSMutableArray阵列容量：columnCount]；
对于（int i=0；i

---

现在，由于

[sideArray replaceObjectAtIndex:columnIndex withObject:rowArray]组中的所有图像下载后不调用。找不到正确的解决方案。。有什么帮助吗？
您的阵列设置不正确。只需使用一个数组：

NSMutableArray *matrixArray = [NSMutableArray arrayWithCapacity:rowCount * columnCount];
for (int i = 0; i < rowCount * columnCount; i++) {
    [matrixArray addObject:[NSNull null]];
}

for (int columnIndex = 0; columnIndex < columnCount; columnIndex++) {
    for (int rowIndex = 0; rowIndex < rowCount; rowIndex++) {
        [NSURLConnection sendAsynchronousRequest: request queue: [NSOperationQueue mainQueue] completionHandler:
         ^(NSURLResponse *response, NSData *data, NSError *connectionError)
         {
             if (data.length && nil == connectionError)
             {
                 UIImage *image = [UIImage imageWithData:data];
                 [matrixArray replaceObjectAtIndex:rowIndex * columnCount + columnIndex withObject:image];
             }
         }];
    }
}

NSMutableArray*matrixArray=[NSMutableArray阵列容量：rowCount*columnCount]；
对于（int i=0；i

要从阵列访问图像，请使用
rowIndex*columnCount+columnIndex
阵列设置不正确。只需使用一个数组：

NSMutableArray *matrixArray = [NSMutableArray arrayWithCapacity:rowCount * columnCount];
for (int i = 0; i < rowCount * columnCount; i++) {
    [matrixArray addObject:[NSNull null]];
}

for (int columnIndex = 0; columnIndex < columnCount; columnIndex++) {
    for (int rowIndex = 0; rowIndex < rowCount; rowIndex++) {
        [NSURLConnection sendAsynchronousRequest: request queue: [NSOperationQueue mainQueue] completionHandler:
         ^(NSURLResponse *response, NSData *data, NSError *connectionError)
         {
             if (data.length && nil == connectionError)
             {
                 UIImage *image = [UIImage imageWithData:data];
                 [matrixArray replaceObjectAtIndex:rowIndex * columnCount + columnIndex withObject:image];
             }
         }];
    }
}

NSMutableArray*matrixArray=[NSMutableArray阵列容量：rowCount*columnCount]；
对于（int i=0；i

要从阵列访问图像，请使用
rowIndex*columnCount+columnIndex
阵列设置不正确。只需使用一个数组：

NSMutableArray *matrixArray = [NSMutableArray arrayWithCapacity:rowCount * columnCount];
for (int i = 0; i < rowCount * columnCount; i++) {
    [matrixArray addObject:[NSNull null]];
}

for (int columnIndex = 0; columnIndex < columnCount; columnIndex++) {
    for (int rowIndex = 0; rowIndex < rowCount; rowIndex++) {
        [NSURLConnection sendAsynchronousRequest: request queue: [NSOperationQueue mainQueue] completionHandler:
         ^(NSURLResponse *response, NSData *data, NSError *connectionError)
         {
             if (data.length && nil == connectionError)
             {
                 UIImage *image = [UIImage imageWithData:data];
                 [matrixArray replaceObjectAtIndex:rowIndex * columnCount + columnIndex withObject:image];
             }
         }];
    }
}

NSMutableArray*matrixArray=[NSMutableArray阵列容量：rowCount*columnCount]；
对于（int i=0；i

要从阵列访问图像，请使用
rowIndex*columnCount+columnIndex
阵列设置不正确。只需使用一个数组：

NSMutableArray *matrixArray = [NSMutableArray arrayWithCapacity:rowCount * columnCount];
for (int i = 0; i < rowCount * columnCount; i++) {
    [matrixArray addObject:[NSNull null]];
}

for (int columnIndex = 0; columnIndex < columnCount; columnIndex++) {
    for (int rowIndex = 0; rowIndex < rowCount; rowIndex++) {
        [NSURLConnection sendAsynchronousRequest: request queue: [NSOperationQueue mainQueue] completionHandler:
         ^(NSURLResponse *response, NSData *data, NSError *connectionError)
         {
             if (data.length && nil == connectionError)
             {
                 UIImage *image = [UIImage imageWithData:data];
                 [matrixArray replaceObjectAtIndex:rowIndex * columnCount + columnIndex withObject:image];
             }
         }];
    }
}

NSMutableArray*matrixArray=[NSMutableArray阵列容量：rowCount*columnCount]；
对于（int i=0；i

要从阵列访问图像，请使用
rowIndex*columnCount+columnIndex
[sideArray replaceObjectAtIndex:columnIndex withObject:rowArray]
不在completionHandler中，因此代码将在异步请求之后继续执行。但是，当请求的响应传入时，completionHandler会稍后激发。
[sideArray replaceObjectAtIndex:columnIndex withObject:rowArray]
不在completionHandler中，因此代码将在异步请求之后继续执行。但是，当请求的响应传入时，completionHandler会稍后激发。
[sideArray replaceObjectAtIndex:columnIndex withObject:rowArray]