在iPhone sdk中问题MFMessageComposerViewController

Question

我正在尝试实现一个SMS应用程序.当我试图发送我的短信时,我在[self.navigationController presentModalViewController:picker animated:YES];中得到了一个异常.我对此很新.你能帮帮我吗？我的代码如下.

MFMessageComposeViewController *picker = [[MFMessageComposeViewController alloc] init];
picker.delegate = self;

picker.recipients = [NSArray arrayWithObject:@"123456789"]; // your recipient number or self for testing
picker.body = @"test from OS4";

[self.navigationController presentModalViewController:picker animated:YES];
[picker release];

我的日志消息如下,

 Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present a nil modal view controller on target <UINavigationController: 0x5b2c120>.

在此先感谢,S.

Answer 1

消息的意思picker是nil,即MFMessageComposeViewController未成功创建.

确保[MFMessageComposeViewController canSendText]返回YES,即.

 if (![MFMessageComposeViewController canSendText]) {
    // show message box for user that SMS cannot be sent
 } else {
    MFMessageComposeViewController* picker = ...;
    ...
 }