[英]Pass an array from ViewController to AppDelegate
我在ViewController中設置了一個數組名為浮點值的playingRates。 我想在我的appdelegate中的函數中使用這些值。 我如何從我的appdelegate中訪問這些值?
ViewController.h
@interface P15ViewController : UIViewController <GuitarStringsViewDelegate>
{
float playbackRates[6];
}
ViewController.m
- (void)viewDidLoad
{
self.guitarStringView.delegate = self;
chordNameLabel.text = chordName;
self.guitarStringView.chordName=chordName;
if([chordName isEqualToString:@"A"]){
playbackRates[0] = 1.0;
playbackRates[1] = 1.0;
playbackRates[2] = 2 * pow(2, (2/12));
playbackRates[3] = 2 * pow(2, (2/12));
playbackRates[4] = 2 * pow(2, (2/12));
playbackRates[5] = 1.0;
}
else if([chordName isEqualToString:@"B"]){
//set rates
}
else if([chordName isEqualToString:@"C"]){
//set rates
}
[super viewDidLoad];
}
appdelegate.h
#import <UIKit/UIKit.h>
#import <PAEEngine/PAEEngine.h>
@interface P15AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
-(void)play:(int)index velocity:(float)velocity;
@end
appdelegate.m-需要通過play方法中for循環內數組中的每個值來設置player.rate
#import "P15AppDelegate.h"
#import "P15ViewController.h"
@interface P15AppDelegate ()
@property (nonatomic, strong) PAEAudioHost* host;
@property (nonatomic, strong) NSArray* channelStrips;
@property (nonatomic, strong) NSArray* filemnames;
@property (nonatomic) int nextVoice;
@end
@implementation P15AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.host = [PAEAudioHost audioHostWithNumOutputs:2];
self.filemnames = @[@"guitar-E1.wav", @"guitar-A2.wav", @"guitar-D3.wav",
@"guitar-G3.wav", @"guitar-B3.wav", @"guitar-E4.wav"];
const int numVoices = 8;
NSMutableArray* channelStrips = [[NSMutableArray alloc] initWithCapacity:numVoices];
for (int i = 0; i < numVoices; ++i)
{
PAEChannelStrip* channelStrip = [PAEChannelStrip channelStripWithNumChannels:2];
[channelStrips addObject:channelStrip];
}
self.channelStrips = [NSArray arrayWithArray:channelStrips];
PAEAmplitude* amp = [PAEAmplitude amplitudeWithNumInputs:2];
amp.input = [PAEMixer mixerWithSources:self.channelStrips];
amp.level.input = [PAEConstant constantWithValue:1.0 / numVoices];
self.host.mainMix = amp;
[self.host start];
return YES;
}
-(void)play:(int)index velocity:(float)velocity;
{
if (index >= 0 && index < self.filemnames.count)
{
PAEAudioFilePlayer* player = [PAEAudioFilePlayer audioFilePlayerNamed:self.filemnames[index]];
player.loop = NO;
player.rate - playbackRates[i]; --> **NEED TO ACCESS ARRAY HERE**
PAEAmplitude* amp = [PAEAmplitude amplitudeWithNumInputs:player.numChannels];
amp.input = player;
amp.level.input = [PAEConstant constantWithValue:velocity];
PAEChannelStrip* channelStrip = self.channelStrips[self.nextVoice];
channelStrip.input = amp;
self.nextVoice++;
if (self.nextVoice == self.channelStrips.count)
self.nextVoice = 0;
}
}
@end
首先,您需要編寫一個公共的訪問在您的UIViewController子類的playbackRates陣列命名P15ViewController。
P15ViewController.h添加-
- (float)playbackRateAtIndex:(NSInteger)index;
P15ViewController.m添加-
- (float)playbackRateAtIndex:(NSInteger)index {
return playbackRates[index];
}
您的appDelegate需要了解此方法,因此請在您的P15AppDelegate.m中導入P15ViewController.h ,我認為您已經完成了。
然后假設的viewController是的appDelegate的RootViewController的 ,那么你可以用下面的代碼訪問它。
更換-
player.rate - playbackRates[i]; --> **NEED TO ACCESS ARRAY HERE**
與-
player.rate = [(P15ViewController*)self.window.rootViewController playbackRateAtIndex:i];
需要進行類型轉換,以便啟用訪問器(更具體地說是getter)的調用。
如果需要更直接的接入方式則改變吸氣或添加其他消氣劑在P15ViewController.m返回playbackRates陣列的輸入地址,這樣的-
- (float*)playbackRatesArray {
return &playbackRates;
}
記住也要更新頭文件!
並從P15AppDelegate.m像這樣訪問它,因為C數組只是一個指針-
float* playbackRates = [(P15ViewController*)self.window.rootViewController playbackRatesArray];
player.rate = playbackRates[i];
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