利用 AFN 上传相册或拍照图片

由于项目中多处需要上传图片，我们可以自定义上传图片请求，自定义调取相册及拍照，方便多处使用时调用。

主要步骤：

自定义ZLImagePicker, 从相册选择图片或者拍照上传图片页面
请求上传你选取的相册图片或者拍照图片（经过压缩处理）
获取到第一步图片url上传给服务器
回显图片（当然进入该界面时先判断是否有图片，无图则展示占位图片，否则就回显图片）

###Step1. 自定义ZLImagePicker, 从相册选择图片或者拍照上传图片页面

用于present UIImagePickerController对且allowsEditing 是否允许用户编辑图像:

+ (void)showImagePickerFromViewController:(UIViewController *)viewController allowsEditing:(BOOL)allowsEditing finishAction:(ZLImagePickerFinishAction)finishAction {
    if (ZLImagePickerInstance == nil) {
        ZLImagePickerInstance = [[ZLImagePicker alloc] init];
    }
    
    [ZLImagePickerInstance showImagePickerFromViewController:viewController
                                                allowsEditing:allowsEditing
                                                 finishAction:finishAction];
}

- (void)showImagePickerFromViewController:(UIViewController *)viewController
                            allowsEditing:(BOOL)allowsEditing
                             finishAction:(ZLImagePickerFinishAction)finishAction {
    _viewController = viewController;
    _finishAction = finishAction;
    _allowsEditing = allowsEditing;
    
    UIActionSheet *sheet = nil;
    
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        sheet = [[UIActionSheet alloc] initWithTitle:nil
                                            delegate:self
                                   cancelButtonTitle:@"取消"
                              destructiveButtonTitle:nil
                                   otherButtonTitles:@"拍照", @"从相册选择", nil];
    }else {
        sheet = [[UIActionSheet alloc] initWithTitle:nil
                                            delegate:self
                                   cancelButtonTitle:@"取消"
                              destructiveButtonTitle:nil
                                   otherButtonTitles:@"从相册选择", nil];
    }
    
    UIView *window = [UIApplication sharedApplication].keyWindow;
    [sheet showInView:window];
}

###Step2. 封装的上传图片的网络请求(图片压缩) ZLUploadImage 文件利用 afn 上传一张图片:

#import "AFNetworking.h"

/**
 *  上传图片的网络请求(图片压缩)
 *
 *  @param url              上传图片的网络请求地址
 *  @param name             和后台包名一致
 *
 */
+ (void)post:(NSString *)url image:(UIImage *)image name:(NSString *)name success:(void (^)(id json))success failure:(void (^)(NSError *error))failure {
    
    // 1.创建网络管理者
    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    
    // 2.拼接请求参数url 也可在具体控制器请求里传入
//    NSDictionary *dict = @{@"userId" : [YYPAccountTool getUserId]};
    NSDictionary *dict; // 这里按实际情况的用户id上传
    
    // 3.发送请求
    [manager POST:url parameters:dict constructingBodyWithBlock:
     ^void(id<AFMultipartFormData> formData) {
         
         NSData *imageData = UIImageJPEGRepresentation(image, 0.5);//进行图片压缩
         
         // 使用日期生成图片名称
         NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
         formatter.dateFormat = @"yyyyMMddHHmmss";
         NSString *fileName = [NSString stringWithFormat:@"%@.png",[formatter stringFromDate:[NSDate date]]];
         // 任意的二进制数据MIMEType application/octet-stream
         [formData appendPartWithFileData:imageData name:name fileName:fileName mimeType:@"image/png"];
         
     } success:^void(NSURLSessionDataTask * task, id responseObject) {
         
         if (success) {
             success(responseObject);
         }
         
     } failure:^void(NSURLSessionDataTask * task, NSError * error) {
         
         if (failure) {
             failure(error);
         }
     }];
}

###Step3. 获取到第一步图片url上传给服务器

需要和各位自己后台server联调，就属于普通的get/post请求了哟调用拍照或打开相册上传icon图像:

[ZLImagePicker showImagePickerFromViewController:self allowsEditing:YES finishAction:^(UIImage *image) {
        if (image) {
            
            [btn setBackgroundImage:image forState:UIControlStateNormal];
            self.icon = image;
}];

###Step4: 回显图片当然进入该界面时先判断是否有图片，无图则展示占位图片，否则就回显图片

[iconBtn setBackgroundImage:(self.icon == nil ? [UIImage imageNamed:@"icon"]: self.icon) forState:UIControlStateNormal];

PS:插一下，我们产品没让拍照的照片存储到相册:

// 存储图片名称：001.png ~ 009.png

for (int i = 1; i<=9; i++) {
     UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"00%d.png", i]];
       
	 UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
       
	 [NSThread sleepForTimeInterval:1];
    }