iOS7以上系统自定义UIAlertController

来源：互联网发布：新买ssd怎么装系统知乎编辑：程序博客网时间：2024/06/05 10:45

是不是发现原来这段代码：

#pragma mark -
#pragma mark - alert delegate
- (void) willPresentAlertView:(UIAlertView *)alertView
{
for (UIView *subViewin alertView.subviews)
{
UILabel *tmpLabel = (UILabel *)subView;
tmpLabel.textAlignment =NSTextAlignmentLeft;
}
}
在iOS7.0及以上版本不能用（说明苹果对私有api管理越来越严格，猜测），如果还想uialertview文字对其要费一些心思了。

如果你有这样的需求:
1>message 信息显示居左对齐，如下图（iOS6.0和iOS7.1显示）



2>在iOS7.0以下版本标题居中，message居左（如上图）。

我们对上述代理方法稍作更改如下：
#pragma mark -
#pragma mark - alert delegate
- (void) willPresentAlertView:(UIAlertView *)alertView
{
  //由于不希望标题也居左
NSInteger labelIndex = 1;
  //在ios7.0一下版本这个方法是可以的
for (UIView *subViewin alertView.subviews)
{
  if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1)
{
if ([subView isKindOfClass: [UILabelclass]])
{
if (labelIndex > 1)
{
UILabel *tmpLabel = (UILabel *)subView;
tmpLabel.textAlignment =NSTextAlignmentLeft;
}
//过滤掉标题
labelIndex ++;
}
}
}
}
但这只能在ios7.0以下版本可以生效；如果是8.0，处理方式还不一样，具体如下：
- (void) showAlertWithMessage:(NSString *) message
{
//8.0
  if (NSFoundationVersionNumber > NSFoundationVersionNumber_iOS_7_1) {
  UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"ffff"message:message preferredStyle:UIAlertControllerStyleAlert];

  NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
  //paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
paragraphStyle.alignment = NSTextAlignmentLeft;
  //行间距
paragraphStyle.lineSpacing = 5.0;

  NSDictionary * attributes = @{NSFontAttributeName : [UIFont systemFontOfSize:18.0],NSParagraphStyleAttributeName : paragraphStyle};
  NSMutableAttributedString *attributedTitle = [[NSMutableAttributedString alloc]initWithString:message];
[attributedTitle addAttributes:attributes range:NSMakeRange(0, message.length)];
[alertController setValue:attributedTitle forKey:@"attributedMessage"];//attributedTitle\attributedMessage
  //end ---


  UIAlertAction *defaultAction1 = [UIAlertAction actionWithTitle:@"cancel"
  style: UIAlertActionStyleDefault
  handler:^(UIAlertAction *action) {
  UITextField *textField = alertController.textFields[0];
  NSLog(@"text was %@", textField.text);
}];
  UIAlertAction *defaultAction2 = [UIAlertAction actionWithTitle:@"ok"
  style: UIAlertActionStyleDefault
  handler:^(UIAlertAction *action) {
  NSLog(@"ok btn");

[alertControllerdismissViewControllerAnimated:YES completion:nil];

}];

[alertController addAction:defaultAction1];
[alertController addAction:defaultAction2];
  //添加textfield

  UIViewController *rootViewController = [UIApplicationsharedApplication].keyWindow.rootViewController;
[rootViewController presentViewController:alertController animated: YES completion: nil];

}else{

  UIAlertView *tmpAlertView = [[UIAlertView alloc] initWithTitle:@"测试换行"
     message:message
  delegate:self
     cancelButtonTitle:nil
     otherButtonTitles:@"知道了", nil];

  //如果你的系统大于等于7.0

  if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber_iOS_6_1)
{
  CGSize size = [self.messageString sizeWithFont:[UIFont systemFontOfSize:15]constrainedToSize:CGSizeMake(240, 1000) lineBreakMode:NSLineBreakByTruncatingTail];

  UILabel *textLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 240, size.height)];
textLabel.font = [UIFont systemFontOfSize:15];
textLabel.textColor = [UIColor blackColor];
textLabel.backgroundColor = [UIColor clearColor];
textLabel.lineBreakMode = NSLineBreakByWordWrapping;
textLabel.numberOfLines = 0;
textLabel.textAlignment = NSTextAlignmentLeft;
textLabel.text = self.messageString;
[tmpAlertView setValue:textLabel forKey:@"accessoryView"];

  //这个地方别忘了把alertview的message设为空
tmpAlertView.message = @"";

}

[tmpAlertView show];
}

}
这样的话就可以了。

调用这个方法：
- (void)viewDidLoad
{
[superviewDidLoad];

  self.view.backgroundColor = [UIColorgrayColor];

  self.messageString =@"1.第一行我是3个子\n2.第二行我是好几个字反正目的是为了和第一行区分开来\n3.哈哈我是陪衬的";

UIButton *alertBtn = [[UIButtonalloc] initWithFrame:CGRectMake(0,200, 320, 40)];
[alertBtn setTitle:@"点我啊，我会alert" forState:UIControlStateNormal];
alertBtn.backgroundColor = [UIColorredColor];
[alertBtnaddTarget:selfaction:@selector(alertBtnTapped)forControlEvents:UIControlEventTouchUpInside];
[self.viewaddSubview:alertBtn];

}
这里别忘声明一个属性self.messageString

0 0