ios - 禁用 UIAlertView 按钮

Question

我正在制作一个带有文本输入的 UIAlertView。

UIAlertView *alertView=[[UIAlertView alloc]initWithTitle:@"Save" message:@"Please Enter the Name of PDF" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"OK", nil];
[alertView setAlertViewStyle:UIAlertViewStylePlainTextInput]

当 UITextField 为空时我想做什么我用委托(delegate)函数禁用 OK 按钮

- (BOOL)alertViewShouldEnableFirstOtherButton:(UIAlertView *)alertView
{

return NO;
}

当用户开始在文本字段中写东西时，OK 按钮应该被启用。

Answer 1

请试试这个

    - (BOOL)alertViewShouldEnableFirstOtherButton:(UIAlertView *)alertView
    {
        /* Retrieve a text field at an index - 
           raises NSRangeException when textFieldIndex is out-of-bounds.

         The field at index 0 will be the first text field
         (the single field or the login field),

         The field at index 1 will be the password field. */

         /*
         1> Get the Text Field in alertview

         2> Get the text of that Text Field

         3> Verify that text length

         4> return YES or NO Based on the length
         */

         return [alertView textFieldAtIndex:0].text.length > 0;

    }