写入plist文件
NSString *plistPath = @"/private/var/mobile/Media/iTunes_Control/iTunes/Ringtones.plist";
NSMutableDictionary *dictionary = [NSMutableDictionary dictionaryWithContentsOfFile:plistPath];
[[dictionary objectForKey:@"Ringtones"] setObject:ringtones forKey:ringName];
if (![dictionary writeToFile:plistPath atomically:YES]) {
NSLog(@"The new ringtone write to file failured!");
}
NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"Setup" ofType:@"plist"]; //把Setup.plist文件放到项目中就ok了，文件名随意。
NSDictionary *dictionary = [[NSDictionary alloc] initWithContentsOfFile:plistPath]; //根据plistPath内容，将Setup.plist内容读入到一个NSMutableDictionary中 //如果仅仅是读取<u><font color="\"red\"">plist</font></u>内容并显示的话，此处用NSDictionary即可。
//将服务器信息填入视图
serverIP = [[dictionary objectForKey:@"ServerSetup"] objectForKey:@"Server"]; //读取"ServerSetup"层 的"Server"关键字下的内容
serverPort = [[dictionary objectForKey:@"ServerSetup"] objectForKey:@"Port"];
//显示读取的内容。
UIAlertView* alert =[[UIAlertView alloc] initWithTitle:@"IP地址" message:serverIP delegate:Nil cancelButtonTitle:@"OKey" otherButtonTitles:nil, nil];
[alert show];
//将读取到的内容 放入变量中 AccelemeterX = (int)[[dictionary objectForKey:@"Accelerometer"] objectForKey:@"X"];
AccelemeterY = (int)[[dictionary objectForKey:@"Accelerometer"] objectForKey:@"Y"];
AccelemeterZ = (int)[[dictionary objectForKey:@"Accelerometer"] objectForKey:@"Z"];
NSLog(@"x=%@,y=%@,z=%@",AccelemeterX,AccelemeterY,AccelemeterZ);
//如下进行写<u><font color="\"red\"">plist</font></u>操作，注意写<u><font color="\"red\"">plist</font></u>操作，必须使用NSMutableDictionary才行
NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"Setup" ofType:@"plist"]; //把Setup.plist文件放到项目中就ok了，文件名随意。
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] initWithContentsOfFile:plistPath]; //根据plistPath内容，此处必须使用NSMutableDictionary
[[dictionary objectForKey:@"ServerSetup"] setValue:@"abc.abc.abc.abc" forKey:@"Server"]; //将<u><font color="\"red\"">plist</font></u>文件中“ServerSetup”下的“Server”关键字的内容改为“abc.abc.abc.abc”
[dictionary writeToFile:plistPath atomically:YES]; //要想将修改内容写入文件，必须执行这步，否则即使修改了也是没有落实到磁盘上的。
http://www.cocoachina.com/bbs/read.php?tid=104013&keyword=plist