實現用戶登錄的保存密碼功能

plist文件是在ios開發中經常會用到的，用來存儲一些少量的數據，例如手機設備信息，用戶基本信息什么的，不過大量的信息還是用數據庫。像這種登錄保存密碼就是把信息寫入plist文件。

以下是效果圖

       

首先同學們要先搞兩張圖片，一張帶鈎鈎的小方框，一張不帶鈎的小方框，用以顯示密碼是否保存的兩種狀態。大家如果沒有的話，就從上面的圖片截取吧。

建議大家WithOUt IB

程序不大，就寫在一個類里面了先來看看.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

再來看看.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];//作為屬性變量的數組如果不初始化是不能用的，這個數組用來保存UITextFiled中的用戶名和密碼。
    recordPwd = NO;//剛開始把是否保存密碼設置為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];//這個就是那個帶鈎的小框框，之前嘗試用UIButton，但是不好切換button的backgroundView，所以就換了UIImageView,給它添加手勢。
    recordBtn.frame = CGRectMake(180, 130, 40, 40);
    recordBtn.userInteractionEnabled = YES;
    UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(110, 130, 100, 40)];
    label.text = @"記住密碼";
    [self.view addSubview:label];
    [label release];
    
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(recoredBtnClick)];//添加了一個手勢，單擊觸發事件
    tapGesture.numberOfTapsRequired = 1;//點擊一下
    [recordBtn addGestureRecognizer:tapGesture];這里注意是在UIImageView上添加手勢
    [self readUserInfoFromFile];//在圖片初始化之前先讀取plist文件，判斷recordPwd
    
    if (recordPwd) {
        recordBtn.image = [UIImage imageNamed:@"[e-mail]"];
    }
    else{
        recordBtn.image = [UIImage imageNamed:@"[e-mail]"];
    }
    [self.view addSubview:table];
    [self.view addSubview:recordBtn];
    [tapGesture release];
    [table release];
    
}

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

- (void)readUserInfoFromFile//從plist讀取數據
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"data.plist"];
//以上的三句話獲取沙盒中data.plist的路徑。
    NSLog(@"文件路徑：%@",path);
    NSMutableDictionary *saveStock = [[NSMutableDictionary alloc]initWithContentsOfFile:path];//從該路徑讀取文件，注意這里是讀取，跟創建plist的init方法不同，看下面就知道了
    recordPwd = [[saveStock objectForKey:@"recordPwd"]boolValue];//@"recordPwd"是一個key，存到字典何從字典中取值都要用到
    if (!recordPwd)
    {
        nameTextField.text = @"";
        pswTextField.text = @"";
        [saveStock removeAllObjects];//移除字典內所有元素
    }
    else{
        nameTextField.text = [saveStock objectForKey:USERNAME];
        pswTextField.text = [saveStock objectForKey:PASSWORD];
        [pswTextField setSecureTextEntry:YES];//密碼設置為暗文
    }    
    NSLog(@"nameTextField.text==%@,pswTextField.text=%@",nameTextField.text,pswTextField.text);
    NSLog(@"讀取saveStock=%@",saveStock);
    [saveStock release];
}

//把是否記住密碼信息寫進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，注意這里的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) {//如果輸入不為空
        [data setObject:nameTextField.text forKey:USERNAME];//用戶名和密碼存入字典，這里的key用了宏定義，其實@"recordPwd"也可以用，在文中多次使用比較省事
        [data setObject:pswTextField.text forKey:PASSWORD];
    }
    [data setObject:[NSNumber numberWithBool:recordPwd] forKey:@"recordPwd"];
    [data writeToFile:path atomically:YES];
    NSLog(@"是否記住密碼信息==%@",data);
    [data release];
}

- (void)recoredBtnClick//點擊是否記住密碼
{
    UIImage *image = [[UIImage alloc]init];
    if (recordPwd) {
        recordBtn.image = [UIImage imageNamed:@"[e-mail]"];
        recordPwd = NO;
    }
    else{
        recordBtn.image = [UIImage imageNamed:@"[e-mail]"];
        recordPwd = YES;
    }
    [self writePasswordToFile];
    [image release];
}

#pragma mark -tableView代理方法實現-

- (UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSArray *left = [NSArray arrayWithObjects:@"姓名:",@"密碼:", nil];
    NSArray *right = [NSArray arrayWithObjects:@"請輸入用戶名",@"請輸入密碼", 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];//本人智商不夠，所以才去這種笨寫法，不知道有沒高手能用循環創建來寫？
            [self readUserInfoFromFile];//還要再讀取一次，如果注銷會發生什么？大家可以去試試
        }
    }
    return cell;
}

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

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event//點擊空白處隱藏鍵盤
{
    [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，但是工作還沒玩呢。先去忙了，大家如果有問題給我留言啊！