我在使用方法时遇到问题，我完全感到困惑。 我无法将字符串作为我的方法的变量移交。
我甚至用字符串调用函数，当前没有变量。
Engine *myEngine = [Engine sharedInstance];
[myEngine getContentArrayFromEngine:@"zumbra"];
我的方法
-(NSMutableArray*) getContentArrayFromEngine:(NSString *)catName{
NSMutableSet* categorieContent = [[NSMutableSet alloc] init];
NSLog(@"Catname:%@", catName);
//some more code
}
NSLOG输出 2011-12-18 18：49：44.165 Zitate [77224：15203] Catname：（null）
为什么catName为空???
edit1：完整的代码 ThirdViewController.m
-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
NSString* myTempCatname;
myTempCatname = cell.textLabel.text;
// NSLog(@"test select %@", myTempCatname);
DetailViewController *detailVC = [self.storyboard instantiateViewControllerWithIdentifier:@"detailzitat"];
[self.navigationController pushViewController:detailVC animated:YES];
Engine *myEngine = [Engine sharedInstance];
[myEngine getContentArrayFromEngine:myTempCatname];
}
并在engine.m
中-(NSMutableArray*) getContentArrayFromEngine:(NSString *)catName{
NSMutableSet* categorieContent = [[NSMutableSet alloc] init];
NSLog(@"Übergebener Catname:%@", catName);
// catName=@"zumbra";
// NSLog(@"Inhalt InhalteFromWeb:%@", InhalteFromWeb);
NSLog(@"Catname:%@", catName);
unsigned count = [InhalteFromWeb count];
while (count--) {
NSLog(@"count %d %@", count, [[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY]);
if([[[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY] isEqualToString:catName]) {
[categorieContent addObject:[InhalteFromWeb objectAtIndex:count]];
NSLog(@"Row %d has Content%@",count, [InhalteFromWeb objectAtIndex:count]);
}
}
NSLog(@"Inhalt Category:%@", categorieContent);
NSArray* tempAr = [[NSArray alloc] initWithArray:[categorieContent allObjects]];
return [NSMutableArray arrayWithArray:tempAr];
}
好吧，即使是catName的提示也不起作用。所以我稍微改变了我的代码。
我有一个数组，其中包含每行的类别，标题，内容，作者和图像
我想做两件事 1）获得所有类别的唯一列表（其工作正常） 2）当点击其中一个类别时，打开一个detailView，显示该类别的第一个元素，通过向左滑动跳转到类别中的上一个和下一个项目。
为此，我将设置我选择的类别 第一次尝试是在方法中进行切换，这种方法不起作用。 现在我可以在我的engine.h中设置类别，当显示单个项目时，返回该类别的数组。
但同样，不存储该类别的值。
ThirdViewController.h
#import <UIKit/UIKit.h>
#import "SecondViewController.h"
@interface ThirdViewController : UIViewController<UITableViewDelegate, UITableViewDataSource> {
NSMutableArray* CategoryList;
}
@property (nonatomic, retain) NSMutableArray* CategoryList;
@end
ThirdViewController.m
#import "ThirdViewController.h"
#import "engine.h"
#import "DetailViewController.h"
@implementation ThirdViewController
@synthesize CategoryList;
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
Engine *myEngine = [Engine sharedInstance];
CategoryList = [myEngine getCategories];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [CategoryList count];
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier =@"Cell";
UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = [CategoryList objectAtIndex:indexPath.row];
return cell;
}
-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
NSString* myTempCatname;
myTempCatname = cell.textLabel.text;
DetailViewController *detailVC = [self.storyboard instantiateViewControllerWithIdentifier:@"detailzitat"];
[self.navigationController pushViewController:detailVC animated:YES];
Engine *myEngine = [Engine sharedInstance];
[myEngine setCategName:myTempCatname];
NSLog(@"Aufruf %@", myTempCatname);
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
@end
DetailViewController.h
#import <UIKit/UIKit.h>
#import <MessageUI/MFMailComposeViewController.h>
#import "engine.h"
@interface DetailViewController : UIViewController<MFMailComposeViewControllerDelegate> {
IBOutlet UILabel *authorLabel;
IBOutlet UILabel *categoryLabel;
IBOutlet UILabel *titleLabel;
IBOutlet UITextView *contentTextView;
NSString *authorText, *contentText, *categoryText, *titleText, *imageText, *catName;
NSMutableArray *contentArray;
}
@property (nonatomic, retain) IBOutlet UITextView *contentTextView;
@property (nonatomic, retain) IBOutlet UILabel *authorLabel;
@property (nonatomic, retain) IBOutlet UILabel *categoryLabel;
@property (nonatomic, retain) IBOutlet UILabel *titleLabel;
@property (nonatomic, retain) NSString *authorText, *contentText, *categoryText, *titleText, *imageText, *catName;
@property (nonatomic, retain) NSMutableArray *contentArray;
-(IBAction)vorher:(id)sender;
-(IBAction)nachher:(id)sender;
@end
DetailViewController.m
#import "DetailViewController.h"
@implementation DetailViewController
@synthesize contentTextView;
@synthesize authorText, contentText, categoryText, titleText, imageText;
@synthesize authorLabel, categoryLabel, titleLabel;
@synthesize contentArray;
@synthesize catName;
int contentIndex;
int contentMax;
- (IBAction)swipeDetected:(UIGestureRecognizer *)sender {
NSLog(@"Right Swipe detected");
}
-(IBAction) vorher:(id)sender {
NSLog(@"-----VORHER Button gedrückt-------");
if (contentIndex==0) {contentIndex=contentMax-1;}
else {contentIndex--;}
titleText = [[contentArray objectAtIndex:contentIndex] objectForKey:TITLE];
authorText= [[contentArray objectAtIndex:contentIndex] objectForKey:AUTHOR];
contentText= [[contentArray objectAtIndex:contentIndex] objectForKey:CONTENT];
authorLabel.text=authorText;
titleLabel.text=titleText;
contentTextView.text=contentText;
}
-(IBAction) nachher:(id)sender {
NSLog(@"-----Nachher Button gedrückt-------");
if (contentIndex==contentMax-1) {contentIndex=0;}
else {contentIndex++;}
titleText = [[contentArray objectAtIndex:contentIndex] objectForKey:TITLE];
authorText= [[contentArray objectAtIndex:contentIndex] objectForKey:AUTHOR];
contentText= [[contentArray objectAtIndex:contentIndex] objectForKey:CONTENT];
authorLabel.text=authorText;
titleLabel.text=titleText;
contentTextView.text=contentText;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
Engine *myEngine = [Engine sharedInstance];
contentArray = [myEngine getContentArrayFromEngine];
contentMax = [contentArray count];
UISwipeGestureRecognizer *swipeRecognizerRight =
[[UISwipeGestureRecognizer alloc]
initWithTarget:self
action:@selector(vorher:)];
swipeRecognizerRight.direction = UISwipeGestureRecognizerDirectionRight;
[self.view addGestureRecognizer:swipeRecognizerRight];
UISwipeGestureRecognizer *swipeRecognizerLeft =
[[UISwipeGestureRecognizer alloc]
initWithTarget:self
action:@selector(nachher:)];
swipeRecognizerLeft.direction = UISwipeGestureRecognizerDirectionLeft;
[self.view addGestureRecognizer:swipeRecognizerLeft];
titleText = [[contentArray objectAtIndex:contentIndex] objectForKey:TITLE];
authorText= [[contentArray objectAtIndex:contentIndex] objectForKey:AUTHOR];
contentText= [[contentArray objectAtIndex:contentIndex] objectForKey:CONTENT];
authorLabel.text=authorText;
titleLabel.text=titleText;
contentTextView.text=contentText;
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
@end
engine.h
//#import
#define AUTHOR @"author"
#define CATEGORY @"cat"
#define CONTENT @"content"
#define IMAGE @"image"
#define TITLE @"title"
@interface Engine : NSObject {
NSMutableArray* InhalteFromWeb;
NSInteger maxAnzahlInhalte;
NSString* categNameStorage;
}
+ (Engine *) sharedInstance;
- (NSMutableArray*) getZitateArrayFromEngine;
- (NSInteger) getMaxAnzahlZitateFromEngine;
- (NSString*) getAutor:(NSInteger)pos;
- (NSString*) getZitat:(NSInteger)pos;
- (NSString*) getAuthor:(NSInteger)pos;
- (NSString*) getCategory:(NSInteger)pos;
- (NSString*) getContent:(NSInteger)pos;
- (NSString*) getImage:(NSInteger)pos;
- (NSString*) getTitle:(NSInteger)pos;
-(NSMutableArray*) getContentArrayFromEngine;
-(void) setCategName:(NSString *) categNameVariable;
-(NSString*) getCategName;
-(NSMutableArray*) getCategories;
@end
engine.m
#import "Engine.h"
@implementation Engine
static Engine *_sharedInstance;
- (id) init
{
if (self = [super init])
{
// custom initialization
//Beginn my code
NSURL *url = [NSURL URLWithString:@"http://www.*/iMotivate.plist"];
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url];
NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if( theConnection )
{
InhalteFromWeb = [[NSMutableArray alloc] initWithContentsOfURL:url];
maxAnzahlInhalte = [InhalteFromWeb count];
}
else
{
NSLog(@"Connection failed");
}
}
return self;
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
// NSLog(@"Recieving Response...");
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
// NSLog(@"Recieving Data...");
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
message : @"An error has occured.Please verify your internet connection."
delegate:nil
cancelButtonTitle :@"OK"
otherButtonTitles :nil];
[alert show];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
// NSLog(@"DONE. Received Quotes: %d", maxAnzahlZitate);
}
// ###########
+ (Engine *) sharedInstance
{
if (!_sharedInstance)
{
_sharedInstance = [[Engine alloc] init];
}
return _sharedInstance;
}
// Getter and Setter for WebArray
- (NSMutableArray*) getZitateArrayFromEngine{
return InhalteFromWeb;
}
- (NSInteger) getMaxAnzahlZitateFromEngine{
return maxAnzahlInhalte;
}
- (NSString*) getAutor:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:AUTHOR];
}
- (NSString*) getZitat:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:CONTENT];
}
// #######
- (NSString*) getAuthor:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:AUTHOR];
}
- (NSString*) getCategory:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:CATEGORY];
}
- (NSString*) getContent:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:CONTENT];
}
- (NSString*) getImage:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:IMAGE];
}
- (NSString*) getTitle:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:TITLE];
}
-(NSArray*) getCategories {
NSMutableSet* categorieSet = [[NSMutableSet alloc] init];
unsigned count = [InhalteFromWeb count];
while (count--) {
NSString *tempString;
tempString=[[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY];
// NSLog(@"tempString %@", tempString );
[categorieSet addObject:tempString];
}
// NSLog(@"categories from engine %@", categorieSet);
NSArray* tempAr = [[[NSArray alloc] initWithArray:[categorieSet allObjects]]sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
return [NSMutableArray arrayWithArray:tempAr];
}
-(void) setCategName:(NSString *) categNameVariable
{ NSLog(@"categNameStorage 2%@",categNameStorage);
categNameStorage=categNameVariable;
NSLog(@"setCategName 1 %@",categNameVariable);
NSLog(@"categNameStorage 2%@",categNameStorage);
}
-(NSString*) getCategName {
return categNameStorage;
}
-(NSMutableArray*) getContentArrayFromEngine{
NSMutableSet* categorieContent = [[NSMutableSet alloc] init];
NSLog(@"Übergebener Catname:%@", categNameStorage);
// NSLog(@"Inhalt InhalteFromWeb:%@", InhalteFromWeb);
unsigned count = [InhalteFromWeb count];
while (count--) {
// NSLog(@"count %d %@", count, [[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY]);
if([[[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY] isEqualToString:categNameStorage]) {
[categorieContent addObject:[InhalteFromWeb objectAtIndex:count]];
// NSLog(@"Row %d has Content%@",count, [InhalteFromWeb objectAtIndex:count]);
}
}
// NSLog(@"Inhalt Category:%@", categorieContent);
NSArray* tempAr = [[NSArray alloc] initWithArray:[categorieContent allObjects]];
return [NSMutableArray arrayWithArray:tempAr];
}
@end
答案 0 :(得分：0)
视图控制器中的'catName'必须存在变量冲突。我不确定为什么视图控制器会在范围内，但我敢打赌，如果你将参数更改为“inCatName”，它会没问题。因此，使用这样的命名约定是很好的。