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我剛學習做「Hello,World」應用。但我有一個問題。我想更改代碼,以便結果顯示「World,Hello」,但無法弄清楚我做錯了什麼。Objective-C - Hello World應用修改
這裏是原代碼:
- (IBAction)changeGreeting:(id)sender {
self.userName = self.textField.text;
NSString *nameString = self.userName;
if ([nameString length] == 0) {
nameString = @"World";
}
NSString *greeting = [[NSString alloc] initWithFormat:@"Hello, %@!", nameString];
self.label.text = greeting;
}
,我認爲這是可行的,如果我可以將其更改爲:
- (IBAction)changeGreeting:(id)sender {
self.userName = self.textField.text;
NSString *nameString = self.userName;
if ([nameString length] == 0) {
nameString = @"World";
}
NSString *greeting = [[NSString alloc] initWithFormat:nameString , @"Hello, %@!"];
self.label.text = greeting;
}
但是仍然沒有工作。我該怎麼做才能做到這一點?
我必須問,IBAction是不是連接起來了? – CodaFi