Question

我正在尝试使用PFQuery接收的列中的属性加载uipickerview。我想我已经能够成功加载这些项目并使用findObjectsInBackgroundWithBlock方法将它们存储在我的viewDidLoad方法的数组中。登录到控制台时，数组（查询结果，现在存储在_locationArray中）类似于以下内容

     "<Cinema:TWdBNfe6QF:(null)> {\n    Location = NY;\n    Name = A;\n}",
    "<Cinema:uCXICOaQFw:(null)> {\n    Location = DC;\n    Name = B;\n}",
    "<Cinema:TQ1F0Bj5OS:(null)> {\n    Location = LA;\n    Name = \"A, ICM\";\n}",
    "<Cinema:xiUXXYFhAl:(null)> {\n    Location = \"San Francisco\";\n    Name = C;\n}"

我想在uipickerview中显示位置。

    - (NSInteger)pickerView:(UIPickerView *)pickerView
    numberOfRowsInComponent:(NSInteger)component
    {
    return [_locationArray count];
    NSLog(@"%lu", (unsigned long)[_locationArray count]);//It never logs this count
    }

    - (NSString *)pickerView:(UIPickerView *)pickerView
         titleForRow:(NSInteger)row
        forComponent:(NSInteger)component
    {
    // I'm not sure how to get the location attribute
    // I get a runtime error if I try to access the _locationArray[row] element 
    }

请帮忙！提前致谢。

Answer 1

我要做的是使用for-in循环遍历数组，并创建一个你要添加的新NSMutableArray。例如：

在标题中：

@property NSMutableArray *stringsArray;//Make sure to init in viewDidLoad

在.m：

for(PFObject *object in _locationArray)
{
   [self.stringsArray addObject:[object objectForKey:@"Location"]];

}

然后：

- (NSString *)pickerView:(UIPickerView *)pickerView
         titleForRow:(NSInteger)row
        forComponent:(NSInteger)component
    {
       return [self.stringsArray objectAtIndex:row];
    }

使用PFQuery填充UIPickerView

1 个答案: