在UIPickerViewDelegate方法的末尾显示警告消息 [英] shows warning msg at the end of the UIPickerViewDelegate method

问题描述

我已经在我的应用程序中创建了一个pickerview，并为它的两个组件创建了一个.h文件代码，如下所示:

I have created a pickerview in my application and create two component of it for that in my .h file code is as follows

@interface tweetViewController : UIViewController<UIPickerViewDataSource ,UIPickerViewDelegate> {

    NSArray *activities;
    NSArray *feelings;

}
@property(nonatomic,retain) NSArray *activities;
@property(nonatomic,retain) NSArray *feelings;
@end

之后，在我的.m文件中，我已经为UIPickerViewDataSource和UIPickerViewDelegate实现了强制方法，但是UIPickerViewDatasource的两种强制方法都可以正常工作它的代码是

after that in my .m file i have implemented compulsory method for UIPickerViewDataSource and UIPickerViewDelegate but both compulory methods of UIPickerViewDatasource works fine and its code is

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
        return [activities count];
    }
    else
    {
        return [feelings count];
    }
} return 2;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    if (component==0) {
   return [activities count];
    }
    else
    {
        return [feelings count];
    }
}

但是UIPickerViewDelegate的方法在该方法的末尾显示警告

but the method of UIPickerViewDelegate shows warning at the end of the method

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    switch (component) {
        case 0:
            return [activities objectAtIndex:row];
            break;
        case 1:
            return [feelings objectAtIndex:row];
            break;
    }

}

告诉我为什么会发生警告??

tell me why does the warning occur????

推荐答案

警告控件可能会到达非void函数的末尾." 的意思是说该方法没有返回任何内容，因为方法有一些返回值.

The warning "control may reach end of non-void function.." means to say that the method is returning nothing as the method is having some return value.

    - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
    {
        NSString *strToReturn = @"";
        switch (component) {
            case 0:
                strToReturn = [activities objectAtIndex:row];
                break;
            case 1:
                strToReturn = [feelings objectAtIndex:row];
            break;
        }
        return strToReturn;
    }

按上述方法修改您的代码，警告将不会再惹恼您.

Modify your code as above and the warning will be no more to irritate you.

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