普通的打开方式是：

InputStream inputStream = getAssets().open("test.xml");

带文件夹的：

getAssets().open("database/db.db");

在webview中的打开是：webView.loadUrl("file:///android_asset/test/index.html");

// bs = FileHelp.FileToXML("history.xml", getCon());// 直接读取根目录下的xml文件

bs = FileHelp.FileToXML(getCon().getResources().getAssets().open(
					"test/datasync.xml"), getCon());// 直接读取xml

public static String FileToXML(String filename, Context context) {
		InputStream ios = context.getClassLoader()
				.getResourceAsStream(filename);// 读取XML流
		BufferedReader in = new BufferedReader(new InputStreamReader(ios));
		StringBuffer buffer = new StringBuffer();
		String line = "";
		try {
			while ((line = in.readLine()) != null) {
				buffer.append(line);
			}
		} catch (IOException e1) {
			e1.printStackTrace();
		}
		return buffer.toString();
	}
	
	public static String FileToXML(InputStream ios, Context context) {
		// InputStream ios = context.getClassLoader()
		// .getResourceAsStream(filename);// 读取XML流
		BufferedReader in = new BufferedReader(new InputStreamReader(ios));
		StringBuffer buffer = new StringBuffer();
		String line = "";
		try {
			while ((line = in.readLine()) != null) {
				buffer.append(line);
			}
		} catch (IOException e1) {
			e1.printStackTrace();
		}
		return buffer.toString();
	}

首先，需要导入AddressBook.framework框架，然后在头文件中加入：#import <AddressBook/AddressBook.h>

CFErrorRef error = NULL; 		
ABAddressBookRef addressBook = ABAddressBookCreate();		
ABRecordRef newPerson= ABPersonCreate(); 

ABRecordSetValue(newPerson, kABPersonFirstNameProperty, @"Eric", &error); 		
ABRecordSetValue(newPerson, kABPersonLastNameProperty, @"Gao", &error); 			
ABRecordSetValue(newPerson, kABPersonJobTitleProperty, @"市场部经理", &error);
ABRecordSetValue(newPerson, kABPersonOrganizationProperty, @"移动技术研发", &error);

ABMutableMultiValueRef multiPhone = ABMultiValueCreateMutable(kABMultiStringPropertyType);			
ABMultiValueAddValueAndLabel(multiPhone, @"12345678", kABPersonPhoneMainLabel, NULL);           			
ABRecordSetValue(newPerson, kABPersonPhoneProperty, multiPhone, &error);			
CFRelease(multiPhone);

ABMutableMultiValueRef multiEmail = ABMultiValueCreateMutable(kABMultiStringPropertyType);
ABMultiValueAddValueAndLabel(multiEmail, @"别墅", kABHomeLabel, NULL);
ABRecordSetValue(newPerson, kABPersonEmailProperty, multiEmail, &error);
CFRelease(multiEmail);

ABMutableMultiValueRef urlMultiValue = ABMultiValueCreateMutable(kABMultiStringPropertyType);
ABMultiValueAddValueAndLabel(urlMultiValue,@"www.google.cn", kABPersonHomePageLabel, NULL);
ABRecordSetValue(newPerson, kABPersonURLProperty, urlMultiValue, &error);
CFRelease(urlMultiValue);

ABMutableMultiValueRef multiAddress = ABMultiValueCreateMutable(kABMultiDictionaryPropertyType);
NSMutableDictionary *addressDictionary = [[NSMutableDictionary alloc] init];
[addressDictionary setObject:@"北京市海淀区中关村" forKey:(NSString *) kABPersonAddressStreetKey];
ABMultiValueAddValueAndLabel(multiAddress, addressDictionary, kABWorkLabel, NULL);
ABRecordSetValue(newPerson, kABPersonAddressProperty, multiAddress, &error);
CFRelease(multiAddress);

UIImage *image = [UIImage imageNamed:@"head.png"];

if (image) {
	NSData *dataRef = UIImagePNGRepresentation(image); 
	CFDataRef dr = CFDataCreate(NULL, [dataRef bytes], [dataRef length]);
	ABPersonSetImageData(newPerson, dr, &error);
	CFRelease(dr);   			
}	

ABAddressBookAddRecord(addressBook, newPerson, &error); 
CFRelease(newPerson);

ABAddressBookSave(addressBook, &error);

效果图：