[英]Property does not conform to protocol
I am having problems getting my property to conform to my self made protocol my property is declared like this: 我在使我的财产符合我自己制定的协议时遇到问题,我的财产被这样声明:
@property(assign)id <MainViewDatasource> datasource
And I run this code to test if it conforms to the protocol: 然后运行以下代码来测试其是否符合协议:
if ([datasource conformsToProtocol:@protocol(MainViewDatasource)])
NSLog(@"datasource conforms to MainViewDatasource");
if(datasource == nil)
NSLog(@"datasource is nil");
And in the Console it says that datasource is nil. 并且在控制台中说数据源为零。 How do I fix this?
我该如何解决?
如果未设置数据源属性,则该属性将保持默认值0x0(无)。
The code: [datasource conformsToProtocol:@protocol(MainViewDatasource)]
itself only returns a Boolean value after it is executed. 代码:
[datasource conformsToProtocol:@protocol(MainViewDatasource)]
本身仅在执行后返回布尔值。 As others have stated, it doesn't actually set up the datasource property. 正如其他人所述,它实际上并没有设置数据源属性。 If you wanted to do some set up only if the said property conforms to a protocol, you would add something to that if block:
如果您只想在上述属性符合协议的情况下进行一些设置,则可以在if块中添加一些内容:
if ([datasource conformsToProtocol:@protocol(MainViewDatasource)])
{
NSLog(@"datasource conforms to MainViewDatasource");
// do additional set up code here that is needed, now that you know your datasource
// conforms to the MainViewDatasource protocol.
}
if(datasource == nil)
NSLog(@"datasource is nil");
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