实现用户登录的保存密码功能

plist文件是在ios开发中经常会用到的，用来存储一些少量的数据，例如手机设备信息，用户基本信息什么的，不过大量的信息还是用数据库。像这种登录保存密码就是把信息写入plist文件。

以下是效果图





首先同学们要先搞两张图片，一张带钩钩的小方框，一张不带钩的小方框，用以显示密码是否保存的两种状态。大家如果没有的话，就从上面的图片截取吧。

建议大家WithOUt IB

程序不大，就写在一个类里面了先来看看.h文件

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UITextFieldDelegate,UITableViewDelegate,UITableViewDataSource>
{
BOOL recordPwd;
UITextField *nameTextField;
UITextField *pswTextField;

}
@property (retain,nonatomic)UIImageView *recordBtn;
@property (retain,nonatomic)NSMutableArray *cellRightArray;

- (void)readUserInfoFromFile;
- (void)recoredBtnClick;
- (void)writePasswordToFile;
@end

再来看看.m文件：

//
//  ViewController.m
//  plistTest
//
//  Created by changjian on 12-12-3.
//  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//

#import "ViewController.h"

#define USERNAME @"nameTextField"
#define PASSWORD @"pswTextField"

@implementation ViewController
@synthesize recordBtn;
@synthesize cellRightArray;

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
[super viewDidLoad];
cellRightArray = [[NSMutableArray alloc]init];//作为属性变量的数组如果不初始化是不能用的，这个数组用来保存UITextFiled中的用户名和密码。
recordPwd = NO;//刚开始把是否保存密码设置为NO
UITableView *table = [[UITableView alloc]initWithFrame:CGRectMake(10, 20, 300, 100) style:UITableViewStyleGrouped];
table.delegate = self;
table.dataSource = self;
table.backgroundColor = [UIColor whiteColor];

[self.view setBackgroundColor:[UIColor whiteColor]];
recordBtn = [[UIImageView alloc]init];//这个就是那个带钩的小框框，之前尝试用UIButton，但是不好切换button的backgroundView，所以就换了UIImageView,给它添加手势。
recordBtn.frame = CGRectMake(180, 130, 40, 40);
recordBtn.userInteractionEnabled = YES;
UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(110, 130, 100, 40)];
label.text = @"记住密码";
[self.view addSubview:label];
[label release];

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(recoredBtnClick)];//添加了一个手势，单击触发事件
tapGesture.numberOfTapsRequired = 1;//点击一下
[recordBtn addGestureRecognizer:tapGesture];这里注意是在UIImageView上添加手势
[self readUserInfoFromFile];//在图片初始化之前先读取plist文件，判断recordPwd

if (recordPwd) {
recordBtn.image = [UIImage imageNamed:@"check_on@2x.png"];
}
else{
recordBtn.image = [UIImage imageNamed:@"check_off@2x.png"];
}
[self.view addSubview:table];
[self.view addSubview:recordBtn];
[tapGesture release];
[table release];

}

- (void)viewDidUnload
{
[super viewDidUnload];
self.recordBtn = nil;
self.cellRightArray = nil;
}

- (void)readUserInfoFromFile//从plist读取数据
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"data.plist"];
//以上的三句话获取沙盒中data.plist的路径。
NSLog(@"文件路径：%@",path);
NSMutableDictionary *saveStock = [[NSMutableDictionary alloc]initWithContentsOfFile:path];//从该路径读取文件，注意这里是读取，跟创建plist的init方法不同，看下面就知道了
recordPwd = [[saveStock objectForKey:@"recordPwd"]boolValue];//@"recordPwd"是一个key，存到字典何从字典中取值都要用到
if (!recordPwd)
{
nameTextField.text = @"";
pswTextField.text = @"";
[saveStock removeAllObjects];//移除字典内所有元素
}
else{
nameTextField.text = [saveStock objectForKey:USERNAME];
pswTextField.text = [saveStock objectForKey:PASSWORD];
[pswTextField setSecureTextEntry:YES];//密码设置为暗文
}
NSLog(@"nameTextField.text==%@,pswTextField.text=%@",nameTextField.text,pswTextField.text);
NSLog(@"读取saveStock=%@",saveStock);
[saveStock release];
}

//把是否记住密码信息写进data.plist文件
- (void)writePasswordToFile
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"data.plist"];
NSLog(@"filePath:%@",path);
NSMutableDictionary *data = [[NSMutableDictionary alloc]init];//字典初始化，注意这里的init方法，跟-(void)readUserInfoFromFile方法中的字典初始化方法不同。
NSLog(@"self.cellRightArray=%@",self.cellRightArray);
if (nameTextField.text.length != 0||pswTextField.text.length != 0) {//如果输入不为空
[data setObject:nameTextField.text forKey:USERNAME];//用户名和密码存入字典，这里的key用了宏定义，其实@"recordPwd"也可以用，在文中多次使用比较省事
[data setObject:pswTextField.text forKey:PASSWORD];
}
[data setObject:[NSNumber numberWithBool:recordPwd] forKey:@"recordPwd"];
[data writeToFile:path atomically:YES];
NSLog(@"是否记住密码信息==%@",data);
[data release];
}

- (void)recoredBtnClick//点击是否记住密码
{
UIImage *image = [[UIImage alloc]init];
if (recordPwd) {
recordBtn.image = [UIImage imageNamed:@"check_off@2x.png"];
recordPwd = NO;
}
else{
recordBtn.image = [UIImage imageNamed:@"check_on@2x.png"];
recordPwd = YES;
}
[self writePasswordToFile];
[image release];
}

#pragma mark -tableView代理方法实现-

- (UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSArray *left = [NSArray arrayWithObjects:@"姓名:",@"密码:", nil];
NSArray *right = [NSArray arrayWithObjects:@"请输入用户名",@"请输入密码", nil];
static NSString *cellIdentifier = @"cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier]autorelease];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(10, 8, 80, 30)];
label.text = [NSString stringWithFormat:[left objectAtIndex:indexPath.row]];
label.backgroundColor = [UIColor clearColor];
[cell.contentView addSubview:label];
[label release];
if (indexPath.row == 0 ){
nameTextField = [[[UITextField alloc]initWithFrame:CGRectMake(90, 10, 140, 30)]autorelease];
nameTextField.placeholder = [NSString stringWithFormat:[right objectAtIndex:indexPath.row]];
nameTextField.delegate = self;
[cell.contentView addSubview:nameTextField];
}else{
pswTextField = [[[UITextField alloc]initWithFrame:CGRectMake(90, 10, 140, 30)]autorelease];
pswTextField.placeholder = [NSString stringWithFormat:[right objectAtIndex:indexPath.row]];
pswTextField.delegate = self;
[pswTextField setSecureTextEntry:YES];
[cell.contentView addSubview:pswTextField];//本人智商不够，所以才去这种笨写法，不知道有没高手能用循环创建来写？
[self readUserInfoFromFile];//还要再读取一次，如果注销会发生什么？大家可以去试试
}
}
return cell;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 2;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event//点击空白处隐藏键盘
{
[nameTextField resignFirstResponder];
[pswTextField resignFirstResponder];
}

- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

- (void)dealloc {
[cellRightArray release];
[nameTextField release];
[pswTextField release];
[recordBtn release];
[super dealloc];
}

@end

完成了，但是工作还没玩呢。先去忙了，大家如果有问题给我留言啊！