Question

我正在使用Apple的MailComposer示例应用程序从我的应用程序中发送电子邮件（OS 3.0功能）。是否可以使用MFMailComposeViewController将To，Subject或Body字段设置为第一响应者？

换句话说，行为将是：用户按下呈现邮件视图的按钮（presentModalViewController）。显示邮件视图时，光标将放在其中一个字段中，键盘将打开。

我注意到MFMailComposeViewController文档说：

“重要提示：邮件撰写界面本身不可自定义，不得由您的应用程序修改。此外，在显示界面后，您的应用程序不允许对电子邮件内容进行进一步更改。仍然可以使用界面编辑内容，但忽略程序化更改。因此，您必须在呈现界面之前设置内容字段的值。“

但是，我不关心自定义界面。我只想设置firstResponder。有什么想法吗？

Answer 1

您可以使这些字段成为第一个响应者。

如果您将以下方法添加到您的班级......

//Returns true if the ToAddress field was found any of the sub views and made first responder
//passing in @"MFComposeSubjectView"     as the value for field makes the subject become first responder 
//passing in @"MFComposeTextContentView" as the value for field makes the body become first responder 
//passing in @"RecipientTextField"       as the value for field makes the to address field become first responder 
- (BOOL) setMFMailFieldAsFirstResponder:(UIView*)view mfMailField:(NSString*)field{
    for (UIView *subview in view.subviews) {

        NSString *className = [NSString stringWithFormat:@"%@", [subview class]];
        if ([className isEqualToString:field])
        {
            //Found the sub view we need to set as first responder
            [subview becomeFirstResponder];
            return YES;
        }

        if ([subview.subviews count] > 0) {
            if ([self setMFMailFieldAsFirstResponder:subview mfMailField:field]){
                //Field was found and made first responder in a subview
                return YES;
            }
        }
    }

    //field not found in this view.
    return NO;
}

然后，在您呈现MFMailComposeViewController之后，将MFMailComposeViewController的视图与您想成为第一响应者的字段一起传递给该函数。

MFMailComposeViewController *mailComposer = [[MFMailComposeViewController alloc] init];
mailComposer.mailComposeDelegate = self;

/*Set up the mail composer*/

[self presentModalViewController:mailComposer animated:YES];
[self setMFMailFieldAsFirstResponder:mailComposer.view mfMailField:@"RecipientTextField"];
[mailComposer release];

Answer 2

在iOS 6中，不再可以在任何文本字段AFAICT上设置第一响应者。导航视图层次结构最终会显示UIRemoteView，并且此处的子视图将被混淆掉。

Answer 3

您可以尝试在控制器本身上调用becomeFirstResponder。如果这不起作用，您可以尝试在调试器中获取邮件撰写视图的子视图列表，直到找到熟悉的文本字段或文本视图，然后您可以专门编写代码以在代码中设置响应者状态，这可能看起来像这（我不知道这是否有效，但这是一个例子）：

[[[[mailcomposer.view.subviews objectAtIndex:3] subviews] objectAtIndex:2] becomeFirstResponder]

Answer 4

我喜欢简化代码并使其易于理解。只需将以下代码放在：
[self presentModalViewController：mailComposer animated：YES];

for (UIView *subview in mailComposer.view.subviews) {
   NSString *className = [NSString stringWithFormat:@"%@", [subview class]];
   //NSLog(@"%@", className); // list the views - Use this to find another view
   //The view I want to set as first responder: "_MFMailRecipientTextField"
   if ([className isEqualToString:@"_MFMailRecipientTextField"]){
   [subview becomeFirstResponder];
   break; // Stop search.
  }
}

在MFMailComposeViewController中设置第一响应者？

4 个答案: