我如何改变那里的needel值。该代码用于速度计，我不知道如何访问该值。即使在 .h 文件中声明了变量，我也无法访问方法外的变量。我只想让针不受随机功能和计时器的控制，我想让他们重新调整滑块我尝试了几件事，但甚至无法访问进度视图。如果你能帮助我，那就太好了。
代码来自这里：http ://www.mobisoftinfotech.com/blog/iphone/ios-tutorial-custom-speedometer-control/
#import "FirstViewController.h"
#import <QuartzCore/QuartzCore.h>
@implementation FirstViewController
@synthesize needleImageView;
@synthesize speedometerCurrentValue;
@synthesize prevAngleFactor;
@synthesize angle;
@synthesize speedometer_Timer;
@synthesize speedometerReading;
@synthesize maxVal;
/*
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
// Custom initialization
}
return self;
}
*/
/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
}
*/
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
// Add Meter Contents //
[self addMeterViewContents];
[super viewDidLoad];
}
/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/
- (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.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[maxVal release];
[needleImageView release];
[speedometer_Timer release];
[speedometerReading release];
[super dealloc];
}
#pragma mark -
#pragma mark Public Methods
-(void) addMeterViewContents
{
UIImageView *backgroundImageView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 320,460)];
backgroundImageView.image = [UIImage imageNamed:@"main_bg.png"];
[self.view addSubview:backgroundImageView];
[backgroundImageView release];
/*UIImageView *meterImageView = [[UIImageView alloc]initWithFrame:CGRectMake(10, 40, 286,315)];
meterImageView.image = [UIImage imageNamed:@"meter.png"];
[self.view addSubview:meterImageView];
[meterImageView release];*/
// Needle //
UIImageView *imgNeedle = [[UIImageView alloc]initWithFrame:CGRectMake(143,155, 22, 84)];
self.needleImageView = imgNeedle;
[imgNeedle release];
self.needleImageView.layer.anchorPoint = CGPointMake(self.needleImageView.layer.anchorPoint.x, self.needleImageView.layer.anchorPoint.y*2);
self.needleImageView.backgroundColor = [UIColor clearColor];
self.needleImageView.image = [UIImage imageNamed:@"arrow.png"];
[self.view addSubview:self.needleImageView];
// Needle Dot //
UIImageView *meterImageViewDot = [[UIImageView alloc]initWithFrame:CGRectMake(131.5, 175, 45,44)];
meterImageViewDot.image = [UIImage imageNamed:@"center_wheel.png"];
[self.view addSubview:meterImageViewDot];
[meterImageViewDot release];
// Speedometer Reading //
UILabel *tempReading = [[UILabel alloc] initWithFrame:CGRectMake(125, 250, 60, 30)];
self.speedometerReading = tempReading;
[tempReading release];
self.speedometerReading.textAlignment = UITextAlignmentCenter;
self.speedometerReading.backgroundColor = [UIColor blackColor];
self.speedometerReading.text= @"0";
self.speedometerReading.textColor = [UIColor colorWithRed:114/255.f green:146/255.f blue:38/255.f alpha:1.0];
[self.view addSubview:self.speedometerReading ];
// Set Max Value //
self.maxVal = @"100";
/// Set Needle pointer initialy at zero //
[self rotateIt:-118.4];
// Set previous angle //
self.prevAngleFactor = -118.4;
// Set Speedometer Value //
[self setSpeedometerCurrentValue];
}
#pragma mark -
#pragma mark calculateDeviationAngle Method
-(void) calculateDeviationAngle
{
if([self.maxVal floatValue]>0)
{
self.angle = ((self.speedometerCurrentValue *237.4)/[self.maxVal floatValue])-118.4; // 237.4 - Total angle between 0 - 100 //
}
else
{
self.angle = 0;
}
if(self.angle<=-118.4)
{
self.angle = -118.4;
}
if(self.angle>=119)
{
self.angle = 119;
}
// If Calculated angle is greater than 180 deg, to avoid the needle to rotate in reverse direction first rotate the needle 1/3 of the calculated angle and then 2/3. //
if(abs(self.angle-self.prevAngleFactor) >180)
{
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5f];
[self rotateIt:self.angle/3];
[UIView commitAnimations];
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5f];
[self rotateIt:(self.angle*2)/3];
[UIView commitAnimations];
}
self.prevAngleFactor = self.angle;
// Rotate Needle //
[self rotateNeedle];
}
#pragma mark -
#pragma mark rotateNeedle Method
-(void) rotateNeedle
{
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5f];
[self.needleImageView setTransform: CGAffineTransformMakeRotation((M_PI / 180) * self.angle)];
[UIView commitAnimations];
}
#pragma mark -
#pragma mark setSpeedometerCurrentValue
-(void) setSpeedometerCurrentValue
{
if(self.speedometer_Timer)
{
[self.speedometer_Timer invalidate];
self.speedometer_Timer = nil;
}
float hilfe = arc4random() % 100;
self.speedometerCurrentValue = hilfe; // Generate Random value between 0 to 100. //
progress.progress = hilfe/100;
self.speedometer_Timer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(setSpeedometerCurrentValue) userInfo:nil repeats:YES];
self.speedometerReading.text = [NSString stringWithFormat:@"%.2f",self.speedometerCurrentValue];
// Calculate the Angle by which the needle should rotate //
[self calculateDeviationAngle];
}
#pragma mark -
#pragma mark Speedometer needle Rotation View Methods
-(void) rotateIt:(float)angl
{
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.01f];
[self.needleImageView setTransform: CGAffineTransformMakeRotation((M_PI / 180) *angl)];
[UIView commitAnimations];
}
#pragma mark -
#pragma mark Slider changed
-(IBAction) silderchanged:(id)sender
{
int progressAsInt =(int)(slider.value + 0.5f);
NSString *newText =[[NSString alloc] initWithFormat:@"%d",progressAsInt];
sliderbox.text = newText;
//progress.progress = ((slider.value + 0.5f)/100);
}
@end
