Question

目前我正在做一个ios应用程序，允许用户上传文件或图像，但我没有想法如何开始。我需要一些可以让我暂时保留的在线服务器上传文件或图像，可以检索回来。任何简单的例子都可以推荐？

Answer 1

您可以使用 Base64 上传图片。首先，您必须从here将 Base64 添加到您的项目中。我在这里添加了一个示例代码。

- (void) uploadImage {

    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://www.mywebpage.com/upload.json"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:1000.0];

    NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *path = [NSString stringWithFormat:@"%@/design%i.png", docDir, designNum];
    NSLog(@"%@",path);

    NSData *imageData = UIImagePNGRepresentation([UIImage imageWithContentsOfFile:path]);
    [Base64 initialize];
    NSString *imageString = [Base64 encode:imageData];

    NSUInteger length = [imageString length];
    NSUInteger chunkSize = 1000;

    NSUInteger thisChunkSize = length - offset > chunkSize ? chunkSize : length - offset;
    NSString *chunk = [imageString substringWithRange:NSMakeRange(offset, thisChunkSize)];
    offset += thisChunkSize;

    NSArray *keys = [NSArray arrayWithObjects:@"design",@"design_id",@"fragment_id",nil];
    NSArray *objects = [NSArray arrayWithObjects:chunk,@"design_id",[NSString stringWithFormat:@"%i", chunkNum],nil];
    NSDictionary *jsonDictionary = [NSDictionary dictionaryWithObjects:objects forKeys:keys];

    NSError *error;
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:jsonDictionary options:kNilOptions error:&error];

    [request setHTTPMethod:@"POST"];
    [request setValue:[NSString stringWithFormat:@"%d",[jsonData length]] forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
    [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:jsonData];

    [self startAsyncLoad:request withTag:[NSString stringWithFormat:@"tag%i",chunkNum]];

    if (offset > length) {
        stopSending = YES;
    }

}

您也可以参考：

Convert between UIImage and Base64 string

关于ios开发的图像和文件上传器的建议示例

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