如果声明空UILabel [英] if statement with empty UILabel

问题描述

我有一个从文本文件加载的UILabel。有时文本文件中包含某些内容，有时它是空的。所以有时候UILabel是空白的，有时它里面有文字。

I have a UILabel that is loaded form a text file. Sometimes the text file has something in it and sometimes it is empty. So sometimes the UILabel is blank and sometimes it has text in it.

我想编写一个if语句，说明如果UILabel是空白的话，如果它有文本，则做另外一件事。

I want to write an if statement that says if the UILabel is blank do one thing else if it has text in it do another thing.

我试过

if (self.label.text = NULL)

和

if (self.label.text = @"") 

但它无法正常工作。

使用 if（self.label.text = @），我得到if语句，但是else语句不起作用。

With the if (self.label.text = @""), I get the if statement to happen but the else statement doesn't work.

这是我的代码

NSString *stuff3 = @"/Stuff";
NSString *titleName = [familyDictionary objectForKey:@"identity"];

NSArray *paths3 = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
                                                      NSUserDomainMask, YES);
NSString *documentsDirectory3 = [paths3 objectAtIndex:0];
NSString *stuffPath3 = [documentsDirectory3 stringByAppendingPathComponent:stuff3];
NSString *fullPath3 = [stuffPath3 stringByAppendingPathComponent:titleName];

self.title = [NSString stringWithContentsOfFile:fullPath3  encoding:NSUTF8StringEncoding error:NULL];
NSLog(@"full path 3 >>>%@",fullPath3);

NSString *stuff4 = @"/Stuff/Objects";
NSString *textName3 = [familyDictionary objectForKey:@"identity"];
NSArray *paths2 = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
                                                      NSUserDomainMask, YES);
NSString *documentsDirectory2 = [paths2 objectAtIndex:0];
NSString *stuffPath = [documentsDirectory2 stringByAppendingPathComponent:stuff4];
NSString *fullPath2 = [stuffPath stringByAppendingPathComponent:textName3];
self.wordlabel.text = [NSString stringWithContentsOfFile:fullPath2  encoding:NSUTF8StringEncoding error:NULL];

//Now load the image at fullPath and install it into our image view's image property.
 NSLog(@"full path 3 >>>%@",fullPath2);

if(self.wordlabel.text = @"") 
{
    [textView setTitle:[NSString stringWithContentsOfFile:fullPath3  encoding:NSUTF8StringEncoding error:NULL] forState:UIControlStateNormal] ;
    textView.titleLabel.adjustsFontSizeToFitWidth = TRUE;
}
else
{
    [textView setTitle:[NSString stringWithContentsOfFile:fullPath2  encoding:NSUTF8StringEncoding error:NULL] forState:UIControlStateNormal] ;
    textView.titleLabel.adjustsFontSizeToFitWidth = TRUE;
}

推荐答案

你在做的是比较指针，不适用于字符串。使用此

What you are doing is comparing pointers, which doesn't work with strings. Use this

if ([self.wordlabel.text isEqualToString:@"thestring"])

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