建立及使用UIAlertController

一。UIAlertControllerStyleActionSheet底部

typedef NS_ENUM(NSInteger, UIAlertControllerStyle) {

UIAlertControllerStyleActionSheet = 0,底部

UIAlertControllerStyleAlert 中間

}

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"自定義背景" message:nil preferredStyle:UIAlertControllerStyleActionSheet];//建立對象
	[self presentViewController:alertController animated:YES completion:nil];//展現alertController，相似於拍照的UIImagePickerController，是一個試圖控制器。
	UIAlertAction *cancleAction = [UIAlertAction actionWithTitle:@"取消cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
		NSLog(@"cancel");//點擊按鈕觸發的事件在這裏寫
	}];//建立按鈕
UIAlertAction *defaultAction = [UIAlertAction actionWithTitle:@"默認default" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
		NSLog(@"默認default");
	}];
	UIAlertAction *defaultAction1 = [UIAlertAction actionWithTitle:@"默認default1" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
		NSLog(@"默認default1");
	}];
	UIAlertAction *resetAction = [UIAlertAction actionWithTitle:@"重置reset" style:UIAlertActionStyleDestructive handler:^(UIAlertAction * _Nonnull action) {
		NSLog(@"reset");
	}];
	UIAlertAction *resetAction1 = [UIAlertAction actionWithTitle:@"重置reset1" style:UIAlertActionStyleDestructive handler:^(UIAlertAction * _Nonnull action) {
		NSLog(@"reset1");
	}];
	[alertController addAction:cancleAction];//添加按鈕
	[alertController addAction:defaultAction1];
	[alertController addAction:defaultAction];
	[alertController addAction:resetAction];
	[alertController addAction:resetAction1];

注：在蘋果上，Cancel按鈕在左邊/最底部，其餘的按添加順序顯示。

UIAlertActionStyle有三種：UIAlertActionStyleDefault = 0, UIAlertActionStyleCancel,和UIAlertActionStyleDestructive，除了style爲cancel只能夠addiction一次，其餘的能夠添加多個按鈕。

二。添加文本輸入框：UIAlertControllerStyleAlert，中間

一、文本輸入框只能添加到Alert的風格中，ActionSheet是不容許的；

二、UIAlertController具備只讀屬性的textFields數組，須要可直接按本身須要的順序添加；

三、添加方式是使用block，參數是UITextField；

四、添加UITextField監聽方法和實現方法。

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"自定義背景" message:nil preferredStyle:UIAlertControllerStyleAlert];//建立對象
UIAlertAction *cancleAction = [UIAlertAction actionWithTitle:@"取消cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
		NSLog(@"cancel");//點擊按鈕觸發的事件在這裏寫
	}];//建立按鈕
	[alertController addAction:cancleAction];//添加上去

	[alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
		textField.placeholder = @"111111";
	}];//添加輸入框
	[alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
		textField.placeholder = @"34444";
		[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textfieldDidChanged:) name:UITextFieldTextDidChangeNotification object:textField];//添加UITextFieldTextDidChangeNotification通知，一旦輸入框text改變，在textfieldDidChanged：方法裏可檢測到輸入狀況
	}];
	[alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
		textField.placeholder = @"jianting";
		[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textfieldDidChanged:) name:UITextFieldTextDidChangeNotification object:textField];
	}];

	UIAlertAction *getAction = [UIAlertAction actionWithTitle:@"默認default" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
		UITextField *login = alertController.textFields[0];
		UITextField *password = alertController.textFields[1];
		UITextField *three = alertController.textFields[2];
		[self.view endEditing:YES];
		NSLog(@"登錄：%@, 密碼：%@,three : %@", login.text, password.text,three.text );
	}];//獲取輸入框中的內容
	
	[alertController addAction:getAction];//添加按鈕，點擊時觸發上面handle的操做。
	
	[self presentViewController:alertController animated:YES completion:nil];//展現視圖控制器，這個必須寫在後面，寫在添加textfield以前顯示不出輸入框的。

- (void)textfieldDidChanged:(NSNotification *)noti {

NSLog(@"\n\n\n%s, noti = %@", __func__, noti);

}

這個是監聽方法示例。

三。一個自定義標題顏色文字的實現。

UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"Dont care what goes here, since we're about to change below" message:@"" preferredStyle:UIAlertControllerStyleActionSheet];
	NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:@"Presenting the great... Hulk Hogan!"];
	[hogan addAttribute:NSFontAttributeName
				  value:[UIFont systemFontOfSize:50.0]
				  range:NSMakeRange(24, 11)];
	[alertVC setValue:hogan forKey:@"attributedTitle"];
	
	
	
	UIAlertAction *button = [UIAlertAction actionWithTitle:@"Label text"
													 style:UIAlertActionStyleDefault
												   handler:^(UIAlertAction *action){
													   //add code to make something happen once tapped
												   }];
//	UIImage *accessoryImage = [UIImage imageNamed:@"someImage"];
//	[button setValue:accessoryImage forKey:@"image"];
	[alertVC addAction:button];
	[self presentViewController:alertVC animated:YES completion:nil];