程序间通信的实现

在iOS里，程序之间都是相互隔离的，目前并没有一个有效的方式来做程序间通信，幸好iOS程序可以很方便的注册自己的URL Scheme，这样就可以通过打开特定URL的方式来传递参数给另外一个程序。

 

至于，如何注册自己的URL Scheme，可以参考：自定义URL Scheme。

 

下面，看一个具体的示例。

 

假设有两个应用：A和B，A应用有两个UITableView，一个是字母类型的，另一个是数字类型的，B应用有两个按钮，一个用来打开A应用的字母列表，另一个用来打开A应用的数字列表，其中，A应用的Info.plist信息如下：

 

A应用的所有代码如下：

 

NavigationAppDelegate.h

 

#import <UIKit/UIKit.h>

@class NavigationViewController;

@interface NavigationAppDelegate : NSObject <UIApplicationDelegate> {
	UIWindow *window;
	UINavigationController *viewController;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UINavigationController *viewController;

@end

 

NavigationAppDelegate.m

 

#import "NavigationAppDelegate.h"
#import "NavigationViewController.h"
#import "NumberViewController.h"

@implementation NavigationAppDelegate

@synthesize window;
@synthesize viewController;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
	NavigationViewController *nav = [[NavigationViewController alloc] init];
	viewController = [[UINavigationController alloc] initWithRootViewController:nav];
	[self.window addSubview:viewController.view];
	[self.window makeKeyAndVisible];
	[nav release];
	return YES;
}

- (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url {
	if ([[url host] isEqualToString:@"com.aurora.nav"]) {
		NSString *viewId = [[url query] substringFromIndex:[[url query] rangeOfString:@"viewId="].location + 7];
		if ([viewId isEqualToString:@"letters"]){
			NavigationViewController *nav = [[NavigationViewController alloc] init];
			[self.viewController pushViewController:nav animated:YES];
			[nav release];
		} else {
			NumberViewController *nav = [[NumberViewController alloc] init];
			[self.viewController pushViewController:nav animated:YES];
			[nav release];
		}
	}
	return YES;
}

- (void)dealloc {
	[viewController release];
	[window release];
	[super dealloc];
}

@end

 

NavigationViewController.h

 

#import <UIKit/UIKit.h>

@interface NavigationViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> {
	NSArray *array;
}

@property(nonatomic, retain) NSArray *array;
@end

 

NavigationViewController.m

 

#import "NavigationViewController.h"

@implementation NavigationViewController

@synthesize array;

- (void)viewDidLoad {
	[super viewDidLoad];
	self.title = @"Letters";
	NSArray *letters = [[NSArray alloc] initWithObjects:@"A", @"B", @"C", @"D", @"E", @"F", @"G", nil];
	self.array = letters;
	[letters release];
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
	return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
	return [array count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
	
	static NSString *CellIdentifier = @"Cell";
	
	UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
	if (cell == nil) {
		cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
	}
	
	cell.textLabel.text = [array objectAtIndex:[indexPath row]];
	
	return cell;
}

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

- (void)viewDidUnload {
	array = nil;
}

- (void)dealloc {
	[array release];
	array = nil;
	[super dealloc];
}

@end

 

NumberViewController.h

 

#import <UIKit/UIKit.h>

@interface NumberViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> {
	NSArray *array;
}

@property(nonatomic, retain) NSArray *array;

@end

 

NumberViewController.m

 

#import "NumberViewController.h"

@implementation NumberViewController

@synthesize array;

- (void)viewDidLoad {
	[super viewDidLoad];
	self.title = @"Numbers";
	NSArray *numbers = [[NSArray alloc] initWithObjects:@"1", @"2", @"3", @"4", @"5", @"6", @"7", nil];
	self.array = numbers;
	[numbers release];
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
	return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
	return [array count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
	
	static NSString *CellIdentifier = @"Cell";
	
	UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
	if (cell == nil) {
		cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
	}
	
	cell.textLabel.text = [array objectAtIndex:[indexPath row]];
	
	return cell;
}

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

- (void)viewDidUnload {
	array = nil;
}

- (void)dealloc {
	[array release];
	array = nil;
	[super dealloc];
}

@end

 

B应用的所有代码如下：

 

RequestViewController.h

 

#import <UIKit/UIKit.h>

@interface RequestViewController : UIViewController {
	
}

- (IBAction) goToLetters;
- (IBAction) goToNumbers;

@end

 

RequestViewController.m

 

#import "RequestViewController.h"

@implementation RequestViewController

- (IBAction) goToLetters{
	NSString *str = @"nav://com.aurora.nav?viewId=%@";
	NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:str, @"letters"]];
	[[UIApplication sharedApplication] openURL:url];
}

- (IBAction) goToNumbers{
	NSString *str = @"nav://com.aurora.nav?viewId=%@";
	NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:str, @"numbers"]];
	[[UIApplication sharedApplication] openURL:url];
}

@end