MFMessageComposeViewController not displaying camera icon

问题

When I bring up a "New Message" manually I will see a camera icon to the left of the text edit area. When I use the MFMessageComposeViewController it will not display this icon which means you cannot insert images. I know this can be done because the guys that made txtAgif can do it. One subtle difference is the Caps is turned on. This might be a clue as to how they are getting this to work.

I know that MFMessageComposeViewController does not allow you to insert images programmatically and that is why I'm doing the copy to UIPasteboard trick. This part works perfectly.

This same question has been asked here and here the question has not been answered except for the "It can't be done."

This is my first post so I did not have a high enough ranking to contribute to the other question posts.

How are they doing this? Is there a trick to MFMessageComposeViewController or are they using something completely different?

回答1:

I have fixed this by following code:

 UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
           pasteboard.persistent = YES;
           NSString *imagefile =app.strimagepath;

           ///  
           BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:imagefile];

           if (fileExists)
           {    
               NSData *data = UIImagePNGRepresentation([UIImage imageWithContentsOfFile:imagefile]);
               pasteboard.image = [UIImage imageWithData:data];
           }
           NSString *phoneToCall = @"sms: 123-456-7890";
           NSString *phoneToCallEncoded = [phoneToCall stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
           NSURL *url = [[NSURL alloc] initWithString:phoneToCallEncoded];

           [[UIApplication sharedApplication] openURL:url];

Here app.strimgPath is the path of image stored in document directory. when the MessageView is opened. Longpress and click on Paste and message will be pasted.

回答2:

I found the answer! Using UIApplication sharedApplication to launch a blank message works while MFMessageComposeViewController does not. Because I'm using the UIPasteboard I do not need to insert items into the body.

    NSString *phoneToCall = @"sms: 123-456-7890";
    NSString *phoneToCallEncoded = [phoneToCall stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
    NSURL *url = [[NSURL alloc] initWithString:phoneToCallEncoded];

    [[UIApplication sharedApplication] openURL:url];

This is a bug in MFMessageComposeViewController because why would they allow images to be inserted into one and not the other. I would insert an image but I'm not allowed to because I do not have enough reputation.

来源：https://stackoverflow.com/questions/9778832/mfmessagecomposeviewcontroller-not-displaying-camera-icon