我将UITableViewCell子类化。基本上会发生的是，当您按下单元格图层上的UITableViewCell绘图时，会导致单元格显示不同。但是，当我删除一个单元格时，该绘图会下降到它下面的单元格。这对我来说似乎表明细胞的格式正在重新使用，这是正常的。因此，我在CellForRowAtIndexPath中重新绘制了单元格，如下所示......
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
AGProgressViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
cell.textLabel.backgroundColor = [UIColor clearColor];
cell.detailTextLabel.backgroundColor = [UIColor clearColor];
//NSLog(@"progress value = %f", [cell.progress floatValue]);
if (!cell) {
cell = [[AGProgressViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
Task * task = nil;
if (indexPath.section == 0){
task = [self.tasksByDay[@"anyday"] objectAtIndex:indexPath.row];
} else if (indexPath.section == 1){
task = [self.tasksByDay[@"monday"] objectAtIndex:indexPath.row];
} else if (indexPath.section == 2){
task = [self.tasksByDay[@"tuesday"] objectAtIndex:indexPath.row];
} else if (indexPath.section == 3){
task = [self.tasksByDay[@"wednesday"] objectAtIndex:indexPath.row];
} else if (indexPath.section == 4){
task = [self.tasksByDay[@"thursday"] objectAtIndex:indexPath.row];
} else if (indexPath.section == 5){
task = [self.tasksByDay[@"friday"] objectAtIndex:indexPath.row];
} else if (indexPath.section == 6){
task = [self.tasksByDay[@"saturday"] objectAtIndex:indexPath.row];
} else if (indexPath.section == 7){
task = [self.tasksByDay[@"sunday"] objectAtIndex:indexPath.row];
}
cell.progress = [NSNumber numberWithFloat:([task.timeSpent floatValue]/[task.time floatValue])];
// this is calling the redrawing method in the cell
[cell drawFillInAtPercent:[task.timeSpent floatValue]/[task.time floatValue]];
//NSLog(@"progress value = %f vs. time spent = %f", [cell.progress floatValue], [task.timeSpent floatValue]/[task.time floatValue]);
cell.textLabel.text = task.name;
cell.detailTextLabel.text = [NSString stringWithFormat:@"%d minutes",
[task.time intValue] - [task.timeSpent intValue]];
return cell;
}
然而，这并没有解决问题。所有这些NSLog都显示每个重新绘制的单元格处于正确的水平。这意味着，由于某种原因，没有在cellForRowAtIndex路径中调用被删除的单元格。奇怪的是文本标签正在发生变化，我在UITableViewCell子类中所做的自定义绘图并没有改变。
这是我在子类中调用的方法。
-(void) drawFillInAtPercent: (float) percent{
//if (percent > 0){
NSLog(@"progress layer at percent %f", percent);
_progressLayer = [CAGradientLayer layer];
_progressLayer.frame = CGRectMake(self.bounds.origin.x,
self.bounds.origin.y,
self.bounds.size.width * percent,
self.bounds.size.height);
_progressLayer.colors = @[(id)[[UIColor colorWithRed:0/255.0 green:0/250.0 blue:250.0/255.0 alpha:1.0f] CGColor],
(id)[[UIColor colorWithRed:150.0/200.0 green:150.0/200.0 blue:150.0/200.0 alpha:.5] CGColor],
(id)[[UIColor colorWithRed:200.0/200.0 green:200.0/200.0 blue:200.0/200.0 alpha:.5] CGColor],
(id)[[UIColor colorWithWhite:0.3f alpha:0.1f] CGColor]];
_progressLayer.locations = @[@0.00f, @0.2f, @0.90f, @1.00f];
[self.layer insertSublayer:_progressLayer atIndex:1];
//}
}
我不知道发生了什么，我似乎无法访问重用的单元格来重绘它。
这些是删除方法：
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
[self deactivateTimers];
NSArray * days = [NSArray arrayWithObjects: @"anyday", @"monday", @"tuesday", @"wednesday", @"thursday", @"friday", @"saturday", @"sunday", nil];
Task * task = self.tasksByDay[days[indexPath.section]][indexPath.row];
if ([task.weekly boolValue]){
task.finished = [NSNumber numberWithBool:1];
} else {
[managedObjectContext deleteObject:task];
}
[self.managedObjectContext save:nil];
[self grabTasksFromContext];
}
}
-(void) grabTasksFromContext{
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription
entityForName:@"Task"
inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
NSError *error;
NSMutableArray * managedObjects = [NSMutableArray arrayWithArray:[managedObjectContext
executeFetchRequest:fetchRequest error:&error]];
int numObjects = [managedObjects count];
for (int i = 0; i < numObjects; i ++){
Task * task = [managedObjects objectAtIndex:i];
NSLog(@"name %@", task.name);
// if the task is finished we don't want it to be displayed in the list
if ([task.finished boolValue]){
NSLog(@"finished");
[managedObjects removeObject:task];
i -= 1;
numObjects -= 1;
}
}
self.tasks = managedObjects;
// This implementation is pretty ugly
// I'm sorry about that and will fix it in the future
// probably the more attractive way to do this is to make an array of the days, and then cycle through that and check through the array of tasks
monday = tuesday = wednesday = thursday = friday = saturday = sunday = anyday = 0;
NSMutableArray * mondayArray = [[NSMutableArray alloc] init];
NSMutableArray * tuesdayArray = [[NSMutableArray alloc] init];
NSMutableArray * wednesdayArray = [[NSMutableArray alloc] init];
NSMutableArray * thursdayArray = [[NSMutableArray alloc] init];
NSMutableArray * fridayArray = [[NSMutableArray alloc] init];
NSMutableArray * saturdayArray = [[NSMutableArray alloc] init];
NSMutableArray * sundayArray = [[NSMutableArray alloc] init];
NSMutableArray * anydayArray = [[NSMutableArray alloc] init];
for (Task * task in self.tasks){
if ([task.day isEqualToString:@"monday"]){
mondayArray[monday] = task;
monday++;
} else if ([task.day isEqualToString:@"tuesday"]){
tuesdayArray[tuesday] = task;
tuesday++;
} else if ([task.day isEqualToString:@"wednesday"]){
wednesdayArray[wednesday] = task;
wednesday++;
} else if ([task.day isEqualToString:@"thursday"]){
thursdayArray[thursday] = task;
thursday++;
} else if ([task.day isEqualToString:@"friday"]){
fridayArray[friday] = task;
friday++;
} else if ([task.day isEqualToString:@"saturday"]){
saturdayArray[saturday] = task;
saturday++;
} else if ([task.day isEqualToString:@"sunday"]){
sundayArray[sunday] = task;
sunday++;
} else {
anydayArray[anyday] = task;
anyday++;
}
}
self.tasksByDay = [[NSDictionary alloc] initWithObjectsAndKeys: mondayArray,@"monday",
tuesdayArray, @"tuesday", wednesdayArray, @"wednesday", thursdayArray, @"thursday",
fridayArray, @"friday", saturdayArray, @"saturday", sundayArray, @"sunday",
anydayArray, @"anyday", nil];
[self.tableView reloadData];
}
任何有关正在发生的事情的帮助或想法都将受到赞赏。
答案 0 :(得分：2)
然而，当我删除一个单元格时，该绘图会下降到它下面的单元格。
这是关键观察：它向我表明，在重绘时，模型（即您的self.tasksByDay[dayName]）尚未尚未更新。删除某一行中的单元格时，需要更新相应日期的taskByDay以从NSArray中删除相应的行。如果没有发生这种情况，删除的任务的数据将影响下一个索引处的单元格的绘制，因此视觉效果似乎“下降”一行。根据你的描述，听起来这正是正在发生的事情。
您需要确保在刷新表格时（或者将单元格删除的通知发送到UITableView）时，模型已经更新，不会删除该行。这样，表格视觉效果会按照您的预期更新。
与问题没有直接关系，但是如果你创建了一个数组
NSArray *dayName = @[@"anyday", @"monday", @"tuesday", @"wednesday", etc.];
您可以用
替换if s的长链
task = [self.tasksByDay[dayName objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
代码中的另一个问题是，每次拨打drawFillInAtPercent:时，都会添加新的CAGradientLayer。当您向上和向下滚动时，重用的单元格会累积新的图层，而不会删除之前添加的图层。您需要更改代码以仅添加一次渐变图层，然后重复使用drawFillInAtPercent:方法中的现有图层。例如，您可以在AGProgressViewCell的指定初始值设定项中添加图层，将其分配给_progressLayer实例变量，并将其添加到图层层次结构中一次。从那时起，drawFillInAtPercent:将更改现有的_progressLayer，而不是每次都创建新的。{/ p>