UIAlertView無法在iPhone應用程序中正確顯示

在iPhone應用程序中，我使用的是alertview來檢查文本框的值是否爲空然後它應該顯示警報其他明智的移動到下一個屏幕，但是當我也再次輸入值時alert view is shows i don 「知道這是什麼問題UIAlertView無法在iPhone應用程序中正確顯示

，如果我還輸入值，那麼也

-(IBAction)buttonClick{ 
    if ([email protected]"") { 

    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Please enter values first" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 


} 


else if ([email protected]"") { 

    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Please enter values first" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 


} 


else if ([email protected]"") { 

    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Please enter values first" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 


} 


else if ([email protected]"") { 

    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Please enter values first" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 


} 
else if ([email protected]"") { 

    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Please enter values first" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 


} 
else if ([email protected]"") { 

    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Please enter values first" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 


} 

else if ([email protected]"") { 

    UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Please enter values first" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 


} 
    else{  

GraphsViewController*targetController=[[GraphsViewController alloc]init]; 

NSString*dogswithMotionSickness=motionSicknessTextField.text; 
NSString*valueOne=cereniaTextField.text; 
NSString*valueTwo=prescriptionTextField.text; 
NSString*valueThree=otherMeansTextField.text; 
NSString*valueFour=overtheCounterTextField.text; 
cerenia=cereniaTextField.text; 


NSString*costToClient=costToClientTextField.text; 
NSString*clinicalMarkup=clinicMarkup.text; 
perMonth=monthTextField.text; 


targetController.perMonth=perMonth; 
targetController.dogswithMotionSickness=dogswithMotionSickness; 

targetController.valueOne=valueOne; 
targetController.valueTwo=valueTwo; 
targetController.valueThree=valueThree; 
targetController.valueFour=valueFour; 
targetController.cerenia=cerenia; 
targetController.costToClient=costToClient; 

targetController.clinicalMarkup=clinicalMarkup; 

[self.navigationController pushViewController:targetController animated:YES]; 

    }}

來源

2012-05-16 user1397714

如果要檢查空字符串，用它總是顯示如果屬實：

if([monthTextField.text isEqualToString:@""])

或

if(monthTextField.text.length > 0)

來源

2012-05-16 05:13:32 Maulik

，還可以使用[monthTextField.text stringByTrimmingCharactersInSet：[NSCharacterSet whitespaceAndNewlineCharacterSet]，忽略白空格或換行符 – HarshIT

此註釋有效，因爲如果字符串中有空格，則此條件將爲false，邏輯將不起作用。 –

@mikebob：很好趕上...我已經更新我的答案..謝謝.. – Maulik

我在AppName的-Prefix.pch定義這兩個宏文件

#define IS_EMPTY_STRING(str) (!(str) || ![(str) isKindOfClass:NSString.class] || [(str) length] == 0) 
#define IS_POPULATED_STRING(str) ((str) && [(str) isKindOfClass:NSString.class] && [(str) length] > 0)

這樣我可以同時檢查空字符串和零字符串對象。

IS_EMPTY_STRING(myString);

來源

2012-05-16 11:06:53 mikebob

也使用

if ([motionSicknessTextField.text isEqualToString:@""] || [motionSicknessTextField.text isEqualTo:nil])

它與零濾波器並且還空白的TextField

的對象或值

來源

2012-05-16 11:17:50

感謝您幫助我已經完成了這個 – user1397714

它的好兄弟......但大多數時候，如果textfield是不分配的，如果文本字段是自定義的這種情況是非常有用的..所以我把這個條件.. :) –

UIAlertView無法在iPhone應用程序中正確顯示

回答

相關問題