放在項目中的plist的不能寫入。需要放到沙盒中操作。

一，讀?。?/p>

NSMutableDictionary *dataDic = [NSMutableDictionary dictionaryWithContentsOfFile:self.plistPath];

二、寫入：

NSMutableDictionary *dataDic = [NSMutableDictionary dictionaryWithContentsOfFile:self.plistPath];

[dataDic setObject:@""forKey:@"password"];

[dataDic writeToFile:self.plistPath atomically:YES];

注意：寫入對象不能不為nil