小编Pad*_*215的帖子

做了一个对象,MyTextBoxCreator.我需要动态制作大量文本框.我希望能够将框架传递给方法.

.h file
-(UITextField *) standardTextField: (CGRect *) myRec;


.m file
-(UITextField *) standardTextField: (CGRect *) myRect
{
    UIView *paddingView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 5, 30)];

    UITextField *myTextField = [[UITextField alloc] initWithFrame:myRect];
    myTextField.font = [UIFont fontWithName:textFieldFont size:textFieldFontSize];
    myTextField.borderStyle = UITextBorderStyleLine;
    myTextField.backgroundColor = [UIColor whiteColor];
    myTextField.textColor = [UIColor textFieldTextColor];
    myTextField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
    myTextField.layer.borderColor = [[UIColor textfieldBorderColor]CGColor];
    myTextField.layer.borderWidth = 1.0f;
    myTextField.leftView = paddingView;
    myTextField.leftViewMode = UITextFieldViewModeAlways;
    myTextField.clearButtonMode = UITextFieldViewModeWhileEditing;

    return myTextField;
}

当我尝试使用myRect为CGRect创建文本字段时,我收到错误:

Sending 'CGRect *' (aka 'struct CGRect *') to …

我有一个两个深的if声明,我想知道我是否可以压缩到单个if stmt:

if ([[myScrollView.subviews objectAtIndex:k] isKindOfClass:[UILabel class]])
{
    if (((UILabel *)[myScrollView.subviews objectAtIndex:k]).tag >= i)
    {
        //code
    }
}

我不确定我是否可以进入:

if ([[myScrollView.subviews objectAtIndex:k] isKindOfClass:[UILabel class]] && ((UILabel *)[myScrollView.subviews objectAtIndex:k]).tag >= i)

因为第二个if条件依赖于第一个(如果它不是UILabel并且没有.tag值)可能会发生坏事吗？

我有一个带有初始化程序的类,它接受一个NSDictionary:

-(id)initWithVector:(NSDictionary *) vectorDictionary;

当我试图传递一个NSDictionary时,它给了我一个错误:

将'VectorClass*_strong'发送到参数类型'NSDictionary*'的不兼容的点类型

码:

// myVectorList is an array of dictionaries
for (NSDictionary *vector in self.myFielder.myVectorList)
{
    if ([vector isKindOfClass:[NSDictionary class]])
    {
        // hardcoded for testing purposes 
        if ([[vector objectForKey:HANDLE] isEqualToString:@"pt07p48u17aj75qx8n2fri9jlkrc262yt8"])
        {
            // GET THE WARNING ON PASSING "VECTOR"
            VectorClass *vector = [[VectorClass alloc] initWithVector:vector];

            [vector retrieveVectorAttributeTable];
            [vector retrieveVectorMetadataTable];
        }
    }
}

如果我转换(NSDictionary*)矢量,没有警告.

vector应该是一本字典,为什么我会收到警告？

我正在使用魔法记录来帮助核心数据保存和多线程.

我用GCD开始一个新线程.在那个新线程中,我检查一个实体是否存在; 如果不是,我想创建一个新的并保存.

saveUsingCurrentThreadContextWithBlock^(NSManagedObjectContext *localContext){}如果在非主线程上调用它,将返回主线程保存吗？

或者我应该将上下文传递给新线程？

编辑:

在主线程上,我创建一个MBProgress指标并创建一个新线程:

MBProgressHUD *HUD = [MBProgressHUD showHUDAddedTo:self.mapView animated:YES];

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{

    Person *person = [Person MR_findFirstByAttribute:NAME withValue:self.user.username];

    if (person == NULL) {
        NSLog(@"SEPERATE THREAD | person %@ does not exist, creating", self.user.username);
        person = [Person MR_createEntity];
        person.name = self.user.username;
        person.uid = self.user.UID;

        [[NSManagedObjectContext MR_contextForCurrentThread] MR_saveOnlySelfWithCompletion:^(BOOL success, NSError *error) {
            [MBProgressHUD hideHUDForView:self.mapView animated:YES];

            Person *person = [Person MR_findFirstByAttribute:NAME withValue:self.user.username];

            if (person) {
                NSLog(@"COMPLETION BLOCK | person exists: %@", person.name);
            }
        }];
    }
    else { …