ios - 返回函数 objective-c

Question

我有一个问题，我想调用一个函数并使用我从该函数获得的值，这是我的函数的代码

-(double)CellWidth{
double width;


if([[UIDevice currentDevice] orientation] == UIDeviceOrientationPortrait || [[UIDevice currentDevice]orientation] == UIDeviceOrientationPortraitUpsideDown){
    NSLog(@"Device is now in Portrait Mode");
    width = 153.6;
}
if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft || [[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeRight) {
    NSLog(@"Device is now in LandscapeLeft Mode ");
    width = 204.6;
}

return width;
}

该函数在 Class1.m 中，但我也在 Class1.h 中这样声明 -(双)单元格宽度；

现在我想在Class2中使用它

Class2.h中的代码

 #import "Class1.h"
 @interface ...
 {
 Class1 *class1;
 }
 @property (nonatomic,release) Class1 *class1;

Class2.m

我想用这个

self.TableView.rowHeight = [class1 CellWidth];

但是 CellWidth 没有被调用，我也没有收到宽度。

Answer 1

您没有传递参数。

你应该有这样的东西:

[self setClass1:[[[Class1 alloc] init] autorelease]];

UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];

//This
[[self horizontalTableView] setRowHeight:[class1 CellWidth:orientation]];

您当前的实现没有调用该函数的原因是您没有告诉它调用该函数。您告诉它调用 [function CellWidth] 而不是 [function CellWidth:orientation]

根据您的反馈，您实际上似乎想要更像这样的东西:

-(double)CellWidth {
    double width = 0;

    UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];

    if(orientation == UIInterfaceOrientationPortrait) {
        NSLog(@"PORTRAIT");
        width = 153.6;
    } else if(orientation == UIInterfaceOrientationLandscapeLeft ||
                orientation == UIInterfaceOrientationLandscapeRight) {
        NSLog(@"LANDSCAPE");
        width = 204.6;
    }

    return width;

}

然后在您的实现中，在 Class2.m 中:

[self setClass1:[[[Function alloc] init] autorelease]];

//This
[[self horizontalTableView] setRowHeight:[class1 CellWidth]];

为了让这更清楚，我将尝试清理这个......

CoolCellInfo.h

@interface CoolCellInfo : NSObject {

}

-(double)cellWidth;

@end

CoolCellInfo.m

@implementation CoolCellInfo

-(id)init {
    self = [super init];

    if(self) {

    }

    return self;
}

-(double)cellWidth {
    double width = 0;

    UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];

    if(orientation == UIInterfaceOrientationPortrait) {
        NSLog(@"PORTRAIT");
        width = 153.6;
    } else if(orientation == UIInterfaceOrientationLandscapeLeft ||
                orientation == UIInterfaceOrientationLandscapeRight) {
        NSLog(@"LANDSCAPE");
        width = 204.6;
    }

    return width;
}

@end

CoolCellUser.h

#import "CoolCellInfo.h"

@interface CoolCellUser : NSObject {
    CoolCellInfo *cellInfo;
}

@property (nonatomic, retain) CoolCellInfo *cellInfo;

@end;

CoolCellUser.m

@implementation CoolCellUser
@synthesize cellInfo;

-(id) init {
    self = [super init];

    if(self) {
         double width = [[self cellInfo] cellWidth];

         NSLog(@"Omg cell width = %f", width);
    }

    return self;
}

#pragma mark Lazy Loader
-(CoolCellInfo *)cellInfo {
    if(cellInfo == nil) {
        [self setCellInfo:[[[CoolCellInfo alloc] init] autorelease]];
    }

    return cellInfo;
}

@end