这是 UITableViewCell 的后续问题- 选中每个部分一行。在这里,我有 2 个部分,每个部分 3 行,如下所示:
搜索距离
250 英尺
1000 英尺
4000 英尺
地图类型
标准
卫星
杂交种
我在第 2 节(地图类型)中遇到问题。我希望将“标准”检查为默认值,用户稍后选择的任何选项都可以保存并传递到另一个视图控制器,该控制器包含要根据所选地图类型显示的地图视图。我当前的代码不允许我为 section2 这样做。任何人,请帮助检查我的代码并建议我需要添加/修改什么?
我一直在尝试了解它在第 1 节(搜索距离)中的工作原理,但我只是不太明白。它似乎涉及委托文件来做缓存的事情。
这里我的代码是:
#import "PAWSettingsViewController.h"
#import "PAWAppDelegate.h"
#import <Parse/Parse.h>
@interface PAWSettingsViewController ()
- (NSString *)distanceLabelForCell:(NSIndexPath *)indexPath;
- (PAWLocationAccuracy)distanceForCell:(NSIndexPath *)indexPath;
- (NSString *)maptypeLabelForCell:(NSIndexPath *)indexPath;
- (PAWMaptypeSelect)maptypeForCell:(NSIndexPath *)indexPath;
@property (nonatomic, assign) CLLocationAccuracy filterDistance;
@end
typedef enum {
kPAWSettingsTableViewDistance = 0,
kPAWSettingsTableViewMaptype,
kPAWSettingsTableViewNumberOfSections
} kPAWSettingsTableViewSections;
typedef enum {
kPAWSettingsTableViewDistanceSection250FeetRow = 0,
kPAWSettingsTableViewDistanceSection1000FeetRow,
kPAWSettingsTableViewDistanceSection4000FeetRow,
kPAWSettingsTableViewDistanceNumberOfRows
} kPAWSettingsTableViewDistanceSectionRows;
typedef enum {
kPAWSettingsTableViewMaptypeSectionStandardRow = 0,
kPAWSettingsTableViewMaptypeSectionSatelliteRow,
kPAWSettingsTableViewMaptypeSectionHybridRow,
kPAWSettingsTableViewMaptypeNumberOfRows
} kPAWSettingsTableViewMaptypeSectionRows;
@implementation PAWSettingsViewController
@synthesize tableView;
@synthesize filterDistance;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
PAWAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
self.filterDistance = appDelegate.filterDistance;
}
return self;
}
#pragma mark - Custom setters
// Always fault our filter distance through to the app delegate. We just cache it locally because it's used in the tableview's cells.
- (void)setFilterDistance:(CLLocationAccuracy)aFilterDistance {
PAWAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
appDelegate.filterDistance = aFilterDistance;
filterDistance = aFilterDistance;
}
#pragma mark - View lifecycle
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Private helper methods
- (NSString *)distanceLabelForCell:(NSIndexPath *)indexPath {
NSString *cellText = nil;
switch (indexPath.row) {
case kPAWSettingsTableViewDistanceSection250FeetRow:
cellText = @"250 feet";
break;
case kPAWSettingsTableViewDistanceSection1000FeetRow:
cellText = @"1000 feet";
break;
case kPAWSettingsTableViewDistanceSection4000FeetRow:
cellText = @"4000 feet";
break;
case kPAWSettingsTableViewDistanceNumberOfRows: // never reached.
default:
cellText = @"The universe";
break;
}
return cellText;
}
- (PAWLocationAccuracy)distanceForCell:(NSIndexPath *)indexPath {
PAWLocationAccuracy distance = 0.0;
switch (indexPath.row) {
case kPAWSettingsTableViewDistanceSection250FeetRow:
distance = 250;
break;
case kPAWSettingsTableViewDistanceSection1000FeetRow:
distance = 1000;
break;
case kPAWSettingsTableViewDistanceSection4000FeetRow:
distance = 4000;
break;
case kPAWSettingsTableViewDistanceNumberOfRows: // never reached.
default:
distance = 10000 * kPAWFeetToMiles;
break;
}
return distance;
}
- (NSString *)maptypeLabelForCell:(NSIndexPath *)indexPath {
NSString *cellText = nil;
switch (indexPath.row) {
case kPAWSettingsTableViewMaptypeSectionStandardRow:
cellText = @"Standard";
break;
case kPAWSettingsTableViewMaptypeSectionSatelliteRow:
cellText = @"Satellite";
break;
case kPAWSettingsTableViewMaptypeSectionHybridRow:
cellText = @"Hybrid";
break;
case kPAWSettingsTableViewMaptypeNumberOfRows: // never reached.
default:
cellText = @"?";
break;
}
return cellText;
}
- (PAWMaptypeSelect)maptypeForCell:(NSIndexPath *)indexPath {
PAWMaptypeSelect maptype = nil;
switch (indexPath.row) {
case kPAWSettingsTableViewMaptypeSectionStandardRow:
maptype = @"Standard";
break;
case kPAWSettingsTableViewMaptypeSectionSatelliteRow:
maptype = @"Satellite";
break;
case kPAWSettingsTableViewMaptypeSectionHybridRow:
maptype = @"Hybrid";
break;
case kPAWSettingsTableViewMaptypeNumberOfRows: // never reached.
default:
maptype = nil;
break;
}
return maptype;
}
#pragma mark - UINavigationBar-based actions
- (IBAction)done:(id)sender {
[self.presentingViewController dismissModalViewControllerAnimated:YES];
}
#pragma mark - UITableViewDataSource methods
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return kPAWSettingsTableViewNumberOfSections;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
switch ((kPAWSettingsTableViewSections)section) {
case kPAWSettingsTableViewDistance:
return kPAWSettingsTableViewDistanceNumberOfRows;
break;
case kPAWSettingsTableViewMaptype:
return kPAWSettingsTableViewMaptypeNumberOfRows;
break;
case kPAWSettingsTableViewNumberOfSections:
return 0;
break;
};
}
- (UITableViewCell *)tableView:(UITableView *)aTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *identifier = @"SettingsTableView";
if (indexPath.section == kPAWSettingsTableViewDistance) {
UITableViewCell *cell = [aTableView dequeueReusableCellWithIdentifier:identifier];
if ( cell == nil )
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue2 reuseIdentifier:identifier];
}
// Configure the cell.
cell.tag = indexPath.section;
cell.textLabel.text = [self distanceLabelForCell:indexPath];
if (self.filterDistance == 0.0) {
NSLog(@"We have a zero filter distance!");
}
PAWLocationAccuracy filterDistanceInFeet = self.filterDistance * ( 1 / kPAWFeetToMeters);
PAWLocationAccuracy distanceForCell = [self distanceForCell:indexPath];
if (abs(distanceForCell - filterDistanceInFeet) < 0.001 ) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
} else if (indexPath.section == kPAWSettingsTableViewMaptype){
UITableViewCell *cell = [aTableView dequeueReusableCellWithIdentifier:identifier];
if ( cell == nil )
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue2 reuseIdentifier:identifier];
}
// Configure the cell.
cell.tag = indexPath.section;
cell.textLabel.text = [self maptypeLabelForCell:indexPath];
//**** I don't know how to do here? ****
return cell;
} else {
return nil;
}
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
switch ((kPAWSettingsTableViewSections)section) {
case kPAWSettingsTableViewDistance:
return @"Search Distance";
break;
case kPAWSettingsTableViewMaptype:
return @"Map Type";
break;
case kPAWSettingsTableViewNumberOfSections:
return @"";
break;
}
}
#pragma mark - UITableViewDelegate methods
// Called after the user changes the selection.
- (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == kPAWSettingsTableViewDistance) {
[aTableView deselectRowAtIndexPath:indexPath animated:YES];
// if we were already selected, bail and save some work.
UITableViewCell *selectedCell = [aTableView cellForRowAtIndexPath:indexPath];
if (selectedCell.accessoryType == UITableViewCellAccessoryCheckmark) {
return;
}
// uncheck all visible cells.
for (UITableViewCell *cell in [aTableView visibleCells]) {
if (cell.accessoryType != UITableViewCellAccessoryNone && cell.tag == indexPath.section) {
cell.accessoryType = UITableViewCellAccessoryNone;
}
}
selectedCell.accessoryType = UITableViewCellAccessoryCheckmark;
PAWLocationAccuracy distanceForCellInFeet = [self distanceForCell:indexPath];
self.filterDistance = distanceForCellInFeet * kPAWFeetToMeters;
}
else if (indexPath.section == kPAWSettingsTableViewMaptype){
[aTableView deselectRowAtIndexPath:indexPath animated:YES];
// if we were already selected, bail and save some work.
UITableViewCell *selectedCell = [aTableView cellForRowAtIndexPath:indexPath];
if (selectedCell.accessoryType == UITableViewCellAccessoryCheckmark) {
return;
}
// uncheck all visible cells.
for (UITableViewCell *cell in [aTableView visibleCells]) {
if (cell.accessoryType != UITableViewCellAccessoryNone && cell.tag == indexPath.section) {
cell.accessoryType = UITableViewCellAccessoryNone;
}
}
selectedCell.accessoryType = UITableViewCellAccessoryCheckmark;
//**** I don't know how to do here? ****
}
}
@end