iOS6.0\iOS7.0\iOS8.0的UIAlertView message 文字对齐设置

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");

[alertController
dismissViewControllerAnimated:YES
completion:nil];

}];

[alertController
addAction:defaultAction1];
[alertController
addAction:defaultAction2];

//添加textfield

UIViewController *rootViewController = [UIApplication
sharedApplication].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];

[alertBtn addTarget:selfaction:@selector(alertBtnTapped)forControlEvents:UIControlEventTouchUpInside];
[self.viewaddSubview:alertBtn];

}
这里别忘声明一个属性self.messageString

源文件下载：http://download.csdn.net/detail/folish_audi/7543541