如何保存字符串到NSUserDefaults?
当前回答
对于Swift,我创建了两个函数,它们将从首选项中保存和检索值。
这对你很有帮助。
//保存对象
static func setObject(value:AnyObject ,key:String)
{
let pref = NSUserDefaults.standardUserDefaults()
pref.setObject(value, forKey: key)
pref.synchronize()
}
static func getObject(key:String) -> AnyObject
{
let pref = NSUserDefaults.standardUserDefaults()
return pref.objectForKey(key)!
}
其他回答
FirstView
{
NSMutableArray *array; }
- (void)viewDidLoad {
[super viewDidLoad];
array = [[NSMutableArray alloc]init];
array = [[NSUserDefaults standardUserDefaults]objectForKey:@"userlist"];
NSLog(@"%lu",(unsigned long)array.count);
if (array>0)
{
for (int i=0; i<array.count; i++)
{
NSDictionary *dict1 = @{@"Username":[[array valueForKey:@"Username"] objectAtIndex:i],@"Mobilenumber":[[array valueForKey:@"Mobilenumber"] objectAtIndex:i],@"Firstname":[[array valueForKey:@"Firstname"] objectAtIndex:i],@"Lastname":[[array valueForKey:@"Lastname"] objectAtIndex:i],@"dob":[[array valueForKey:@"dob"] objectAtIndex:i],@"image":[[array valueForKey:@"image"] objectAtIndex:i]};
NSLog(@"%@",dict1);
NSArray *array1 = [[NSArray alloc]initWithObjects:dict1, nil];
[[NSUserDefaults standardUserDefaults] setObject:array1 forKey:@"UserList"];
}
}
}
image picker
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
self.imaGe.image = chosenImage;
[picker dismissViewControllerAnimated:YES completion:NULL];
}
(IBAction)submitBton:(id)sender { NSMutableArray *array2 = [[NSMutableArray alloc]initWithArray: [[NSUserDefaults standardUserDefaults]objectForKey: @"userlist"]]; UIImage *ima = _imaGe.image; NSData *imagedata = UIImageJPEGRepresentation(ima,100); NSDictionary *dict = @{@"Username":_userTxt.text,@"Lastname":_lastTxt.text,@"Firstname":_firstTxt.text,@"Mobilenumber":_mobTxt.text,@"dob":_dobTxt.text,@"image":imagedata}; [array2 addObject:dict]; [[NSUserDefaults standardUserDefaults]setObject:array2 forKey:@"userlist"]; NSLog(@"%@",array2); [self performSegueWithIdentifier:@"second" sender:self]; } (IBAction)chooseImg:(id)sender { UIImagePickerController *picker = [[UIImagePickerController alloc] init]; picker.delegate = self; picker.allowsEditing = YES; picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; [self presentViewController:picker animated:YES completion:NULL]; }
第二视图{ NSMutableArray * arr;}
- (void)viewDidLoad {
[super viewDidLoad];
arr =[[NSMutableArray alloc]init];
arr = [[NSUserDefaults standardUserDefaults]objectForKey:@"userlist"]; }
#pragma mark- TableView DataSource
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1; }
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return arr.count; }
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *cellId = @"tablecell";
TableViewCell *cell =[tableView dequeueReusableCellWithIdentifier:cellId];
cell.userLbl.text =[[arr valueForKey:@"username"] objectAtIndex:indexPath.row];
cell.ageLbl.text =[[arr valueForKey:@"dob"] objectAtIndex:indexPath.row];
cell.profileImg.image =[UIImage imageNamed:[[arr valueForKey:@"image"] objectAtIndex:indexPath.row]];
return cell; }
下面是如何对Swift做同样的事情;
var valueToSave = "someValue"
NSUserDefaults.standardUserDefaults().setObject(valueToSave, forKey: "preferenceName")
以后把它拿回来;
if let savedValue = NSUserDefaults.standardUserDefaults().stringForKey("preferenceName") {
// Do something with savedValue
}
在Swift 3.0中
var valueToSave = "someValue"
UserDefaults.standard.set(valueToSave, forKey: "preferenceName")
if let savedValue = UserDefaults.standard.string(forKey: "preferenceName") {
}
更准确地说
-(void)saveToUserDefaults:(NSString*)myString
{
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
if (standardUserDefaults) {
[standardUserDefaults setObject:myString forKey:@"timestamps"];
[standardUserDefaults synchronize];
}
}
就像这样:
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
// saving an NSString
[prefs setObject:@"TextToSave" forKey:@"keyToLookupString"];
然后检索:
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
// getting an NSString
NSString *myString = [prefs stringForKey:@"keyToLookupString"];
你应该看看苹果的NSUserDefaults类参考,也可以看看这个教程:iPhone编程教程-使用NSUserDefaults保存/检索数据
用于保存:
[[NSUserDefaults standardUserDefaults]setObject:@"YES" forKey:@"KTerminated"];
[[NSUserDefaults standardUserDefaults]synchronize];
对于检索使用这个:
[[[NSUserDefaults standardUserDefaults]stringForKey:@"KTerminated"] isEqualToString:@"YES"];
推荐文章
- 是否可以为iPhone应用程序(如YouTube和地图)注册一个基于http+域的URL方案?
- 模拟器错误fbssystemservicdomain代码4
- 开始使用instancetype而不是id是否有益?
- 改变UISegmentedControl的字体大小
- 我可以强制UITableView隐藏分隔符之间的空单元格吗?
- 为什么Objective-C文件使用。m扩展名?
- Objective-C for Windows
- 获取用户当前位置/坐标
- 获得推送通知,而应用程序在前台iOS
- 如何取消选定的UITableView单元格?
- 设置自定义UITableViewCells的高度
- 在SwiftUI中创建一个VStack填充屏幕宽度
- 移动文本字段时,键盘出现迅速
- 让iPhone震动
- 将NSString转换为NSDate(然后再转换回来)