ActionSheet样式弹框:
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"title" message:@"message" preferredStyle:UIAlertControllerStyleActionSheet];
UIAlertAction *action = [UIAlertAction actionWithTitle:@"act1" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
}];
UIAlertAction *action2 = [UIAlertAction actionWithTitle:@"act2" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
}];
UIAlertAction *cancle = [UIAlertAction actionWithTitle:@"cancle" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
}];
[alert addAction:action];
[alert addAction:action2];
[alert addAction:cancle];
[self presentViewController:alert animated:YES completion:nil];
设置仅在iPhone: 路径: TARGETS -> Development Info -> Devices
Snip20171208_3.png
上面创建UIAlertControllerStyleActionSheet样式弹框的代码在iPhone手机上运行时没有问题，运行效果如图(四周存在黑边是因为Xcode设置仅在iPhone运行 而模拟器放在了iPad上不适配所致): 此时可看到UIAlertControllerStyleActionSheet运行效果iPhone与iPad效果一致.
Simulator Screen Shot - iPad Pro (9.7 inch) - 2017-12-08 at 14.21.09.png
设置Universal:
Snip20171208_2.png
设置机型为Universal(即: 手机和iPad均支持) 在iPhone上运行效果与上一致，而在iPad上运行时 导致崩溃
报错信息:
Your application has presented a UIAlertController (<UIAlertController: 0x100b790f0>) of style UIAlertControllerStyleActionSheet. The modalPresentationStyle of a UIAlertController with this style is UIModalPresentationPopover. You must provide location information for this popover through the alert controller's popoverPresentationController. You must provide either a sourceView and sourceRect or a barButtonItem. If this information is not known when you present the alert controller, you may provide it in the UIPopoverPresentationControllerDelegate method -prepareForPopoverPresentation.
解决:
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"title" message:@"message" preferredStyle:UIAlertControllerStyleActionSheet];
UIAlertAction *action = [UIAlertAction actionWithTitle:@"act1" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
}];
UIAlertAction *action2 = [UIAlertAction actionWithTitle:@"act2" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
}];
UIAlertAction *cancle = [UIAlertAction actionWithTitle:@"cancle" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
}];
[alert addAction:action];
[alert addAction:action2];
[alert addAction:cancle];
UIPopoverPresentationController *popover = alert.popoverPresentationController;
if (popover)
{
popover.sourceView = self.view;
popover.sourceRect = CGRectMake(0, 0, 100, 100);
popover.permittedArrowDirections = UIPopoverArrowDirectionAny;
}
[self presentViewController:alert animated:YES completion:nil];
Simulator Screen Shot - iPad Pro (9.7 inch) - 2017-12-08 at 14.21.34.png
