如何更改此 UITableViewController 自定义类以动态更改表视图单元格的高度？我为 iPad 和 iPhone 尺寸类别指定了不同的字体大小。
（这是之前与 @rdelmar 讨论的延续）
#import "CREWFoodWaterList.h"
@interface CREWFoodWaterList ()
@end
@implementation CREWFoodWaterList
#define VIEW_NAME @"FoodWaterList" // add to database for this view and notes view
#define VIEW_DESCRIPTION @"Food Water - items to keep available" // to add to the database
#define RETURN_NC @"NCSuggestedContentsMenu" // where to return to when complete processing should be specified there
#define NOTES_TITLE @"Food and Water Notes" // pass to notes VC
#define THIS_NC @"NCFoodWaterList" // pass to next VC (so returns to the NC for this view)
- (IBAction)changedSwitch:(UISwitch *)sender {
if (sender.tag == 0) {
[self saveSwitch: @"switchWater" toValue:[NSNumber numberWithBool:sender.on]];
} else if (sender.tag == 1) {
[self saveSwitch: @"switchCanned" toValue:[NSNumber numberWithBool:sender.on]];
} else if (sender.tag == 2) {
[self saveSwitch: @"switchComfort" toValue:[NSNumber numberWithBool:sender.on]];
} else if (sender.tag == 3) {
[self saveSwitch: @"switchSpecial" toValue:[NSNumber numberWithBool:sender.on]];
}
} // end of changedSwitch
-(void)loadSavedSwitches {
// now set the switches to previously stored values
NSNumber *switchValue;
switchValue = [self getSwitch: @"switchWater"];
if ([switchValue intValue] == 0) {
self.switchWater.on = NO;
} else {
self.switchWater.on = YES;
}
self.textWater.text = [self getDescription:@"switchWater"];
switchValue = [self getSwitch: @"switchCanned"];
if ([switchValue intValue] == 0) {
self.switchCanned.on = NO;
} else {
self.switchCanned.on = YES;
}
self.textCanned.text = [self getDescription:@"switchCanned"];
switchValue = [self getSwitch: @"switchComfort"];
if ([switchValue intValue] == 0) {
self.switchComfort.on = NO;
} else {
self.switchComfort.on = YES;
}
self.textComfort.text = [self getDescription:@"switchComfort"];
// self.textComfort.textColor = [UIColor whiteColor];
switchValue = [self getSwitch: @"switchSpecial"];
if ([switchValue intValue] == 0) {
self.switchSpecial.on = NO;
} else {
self.switchSpecial.on = YES;
}
self.textSpecial.text = [self getDescription:@"switchSpecial"];
}
- (void) createNewSwitches {
// set create all switches and set to off
[self newSwitch: @"switchWater" toValue:@"At least three litres of bottle water per person per day"];
[self newSwitch: @"switchCanned" toValue:@"Canned foods, dried goods and staples"];
[self newSwitch: @"switchComfort" toValue:@"Comfort foods"];
[self newSwitch: @"switchSpecial" toValue:@"Food for infants, seniors and special diets"];
}
// COMMON Methods
- (void)viewDidLoad {
[super viewDidLoad];
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = 50;
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
// set font size for table headers
[[UIDevice currentDevice] model];
NSString *myModel = [[UIDevice currentDevice] model];
NSInteger nWords = 1;
NSRange wordRange = NSMakeRange(0, nWords);
NSArray *firstWord = [[myModel componentsSeparatedByString:@" "] subarrayWithRange:wordRange];
NSString *obj = [firstWord objectAtIndex:0];
if ([obj isEqualToString:@"iPad"]) {
[[UILabel appearanceWhenContainedIn:[UITableViewHeaderFooterView class], nil] setFont:[UIFont boldSystemFontOfSize:26]];}
else if ([obj isEqualToString:@"iPhone"]) {
[[UILabel appearanceWhenContainedIn:[UITableViewHeaderFooterView class], nil] setFont:[UIFont boldSystemFontOfSize:16]];
};
[defaults setObject:NOTES_TITLE forKey: @"VCtitle"]; // pass to notes VC
[defaults setObject:VIEW_NAME forKey: @"VCname"]; // pass to notes VC to use to store notes
[defaults setObject:THIS_NC forKey: @"CallingNC"]; // get previous CallingNC and save it for use to return to in doneAction
[self initializeView];
} // end of viewDidLoad
-(void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[self.tableView reloadData]; // this was necessary to have the cells size correctly when the table view first appeared
}
- (void) initializeView {
CREWAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"View" inManagedObjectContext:context];
NSFetchRequest * request = [[NSFetchRequest alloc] init];
[request setEntity:entityDesc];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"(viewName = %@)", VIEW_NAME];
[request setPredicate:pred];
NSError *error = nil;
NSArray * objects = [context executeFetchRequest:request error:&error];
if ([objects count] == 0) { // create new view instance
NSManagedObject * newView;
newView = [NSEntityDescription insertNewObjectForEntityForName:@"View" inManagedObjectContext:context];
[newView setValue:VIEW_NAME forKey:@"viewName"];
[newView setValue:VIEW_DESCRIPTION forKey:@"viewDescription"];
// create all switches and set to off
[self createNewSwitches];
}
// load all switches
[self loadSavedSwitches];
} // end of initializeView
// create a new switch
- (void) newSwitch:(NSString*)switchName toValue:(NSString*)switchDescription {
NSError *error = nil;
CREWAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSManagedObject * newSwitch;
newSwitch = [NSEntityDescription insertNewObjectForEntityForName:@"Switch" inManagedObjectContext:context];
[newSwitch setValue:VIEW_NAME forKey:@"viewName"];
[newSwitch setValue:switchName forKey:@"switchName"];
[newSwitch setValue:switchDescription forKey:@"switchDescription"];
[newSwitch setValue:[NSNumber numberWithInt:0] forKey:@"switchValue"];
if (! [context save:&error])
// NSLog(@"**** START entering %@",VIEW_NAME);
NSLog(@"newSwitch Couldn't save new data! Error:%@", [error description]);
} // end of newSwitch
// read existing switch settings
- (NSNumber *) getSwitch:(NSString*)switchName {
CREWAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Switch" inManagedObjectContext:context];
NSFetchRequest * request = [[NSFetchRequest alloc] init];
[request setEntity:entityDesc];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"(viewName = %@) AND (switchName = %@)", VIEW_NAME, switchName];
[request setPredicate:pred];
// Execute Fetch Request
NSManagedObjectContext * matches = nil;
NSError *fetchError = nil;
NSArray *objects = [appDelegate.managedObjectContext executeFetchRequest:request error:&fetchError];
if (fetchError) {
};
NSNumber *switchValue;
if (! [objects count] == 0) {
matches = objects [0];
switchValue = [matches valueForKey : @"switchValue"];
}
return switchValue;
} // end of getSwitch
- (NSString *) getDescription:(NSString*)switchName {
CREWAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Switch" inManagedObjectContext:context];
NSFetchRequest * request = [[NSFetchRequest alloc] init];
[request setEntity:entityDesc];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"(viewName = %@) AND (switchName = %@)", VIEW_NAME, switchName];
[request setPredicate:pred];
// Execute Fetch Request
NSManagedObjectContext * matches = nil;
NSError *fetchError = nil;
NSArray *objects = [appDelegate.managedObjectContext executeFetchRequest:request error:&fetchError];
if (fetchError) {
// NSLog(@"**** START entering %@",VIEW_NAME);(@"getSwitch Fetch error:%@", fetchError); // no
};
NSString *switchDescription;
if (! [objects count] == 0) {
matches = objects [0];
switchDescription = [matches valueForKey : @"switchDescription"];
}
return switchDescription;
} // end of getDescription
- (void)saveSwitch:(NSString*)switchName toValue:(NSNumber*)newSwitchValue {
CREWAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = [appDelegate managedObjectContext];
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Switch" inManagedObjectContext:context]; // get switch entity
NSFetchRequest * request = [[NSFetchRequest alloc] init];
[request setEntity:entityDesc];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"(viewName = %@) AND (switchName = %@)", VIEW_NAME, switchName ];
[request setPredicate:pred];
NSManagedObject *matches = nil;
NSError *fetchError = nil;
NSArray * objects = [context executeFetchRequest:request error:&fetchError];
if (![objects count] == 0) {
matches = objects[0];
}
[matches setValue:newSwitchValue forKey:@"switchValue"];
if (! [context save:&fetchError])
// NSLog(@"**** START entering %@",VIEW_NAME);
NSLog(@"saveSwitch Couldn't save data! Error:%@", [fetchError description]); // perhaps this can be Done later
} // end of saveSwitch
// set alternate cells to different colors
- (UIColor *)getUIColorObjectFromHexString:(NSString *)hexStr alpha:(CGFloat)alpha
{
// Convert hex string to an integer
unsigned int hexint = [self intFromHexString:hexStr];
// Create color object, specifying alpha as well
UIColor *color =
[UIColor colorWithRed:((CGFloat) ((hexint & 0xFF0000) >> 16))/255
green:((CGFloat) ((hexint & 0xFF00) >> 8))/255
blue:((CGFloat) (hexint & 0xFF))/255
alpha:alpha];
return color;
}
// Helper method..
- (unsigned int)intFromHexString:(NSString *)hexStr
{
unsigned int hexInt = 0;
// Create scanner
NSScanner *scanner = [NSScanner scannerWithString:hexStr];
// Tell scanner to skip the # character
[scanner setCharactersToBeSkipped:[NSCharacterSet characterSetWithCharactersInString:@"#"]];
// Scan hex value
[scanner scanHexInt:&hexInt];
return hexInt;
}
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *grayishCyan = @"#a3c9ca";
NSString *grayishRed = @"#caa4a3";
UIColor *colorCyan = [self getUIColorObjectFromHexString:grayishCyan alpha:.9];
UIColor *colorPink = [self getUIColorObjectFromHexString:grayishRed alpha:.9];
// // NSLog(@"**** START entering %@",VIEW_NAME);(@"UIColor: %@", colorPink);
if (indexPath.row == 0 || indexPath.row%2 == 0) {
cell.backgroundColor = colorCyan;
}
else {
cell.backgroundColor = colorPink;
}
}
- (IBAction)doneAction:(id)sender {
// NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
UIViewController *viewController = [[UIStoryboard storyboardWithName:@"Main" bundle:nil] instantiateViewControllerWithIdentifier:RETURN_NC]; // previous Navigation controller
[self presentViewController:viewController animated:YES completion:nil];
};
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
@end
