从uitableview中删除+写入plist无法正常工作

Question

我想从uitableview中删除并将其写入我的plist。我对这个客观的iOS编码很新，所以请原谅我的错误

现在我的代码崩溃了：

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0.  The number of rows contained in an existing section after the update (11) must be equal to the number of rows contained in that section before the update (11), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'

这是我在mainViewcontroller中的代码

- (void)viewWillAppear:(BOOL)animated{
// Property List.plist code
//Gets paths from root direcory.
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
//Get documents path.
NSString *documentsPath = [paths objectAtIndex:0];

//Get the path to our PList file.
plistPath = [documentsPath stringByAppendingPathComponent:@"Servers.plist"];

//Check to see if Property List.plist exists in documents.
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath]){
    [[NSFileManager defaultManager]copyItemAtPath:[[NSBundle mainBundle]pathForResource:@"Servers" ofType:@"plist"] toPath:plistPath error:nil];
    //If not in documents, get property list from main bundle.
}
arrayA = [[NSMutableArray alloc] initWithContentsOfFile:plistPath];
NSLog(@"%@\n%@", arrayA, [arrayA valueForKey:@"Hostname"]);

tableData = [arrayA valueForKey:@"Hostname"];
[super viewWillAppear:animated];
[self.tableView reloadData];
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{

    return [tableData count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{
static NSString *cellIdentifier = @"showServerAction";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

if (cell == nil) {

    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];

}

cell.textLabel.text = [tableData objectAtIndex:indexPath.row];

return cell;

}
    - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {

if (editingStyle == UITableViewCellEditingStyleDelete) {
    [tableView beginUpdates];

    [arrayA writeToFile:plistPath atomically: TRUE];
    [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
    [tableView endUpdates];
}
}

更新 这是我的plist的样子。它是一个NSMutableArray

Answer 1

试试这个：

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
  if (editingStyle == UITableViewCellEditingStyleDelete) {

    [tableView beginUpdates];

    // You are going to modify the table view, but you also need
    // to modify the data source of your table. Since tableData
    // is derived from the content of arrayA, the actual data
    // source is arrayA, so we start with that (also, arrayA is
    // a mutable array, so we are allowed to remove objects from
    // it).
    [arrayA removeObjectAtIndex:indexPath.row];

    // Now we also need to modify tableData. If you don't do this,
    // tableData will report the wrong number of rows when
    // numberOfRowsInSection() is called the next time. This is the
    // direct source of the error that you mention in your question
    // (carefully read the error message, it's really meaningful!).
    // A small problem is that tableData is not a mutable array,
    // so we cannot use removeObjectAtIndex: to modify it (that's
    // probably the source of the error you got with Ilya's answer).
    // The solution is to simply recreate tableData from scratch
    // from the content of arrayA.
    tableData = [arrayA valueForKey:@"Hostname"];

    [arrayA writeToFile:plistPath atomically: TRUE];
    [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];

    [tableView endUpdates];
  }
}

Answer 2

删除后必须更改tableData，然后重新加载表视图：

[self.tableView reloadSections:[NSIndexSet  indexSetWithIndex:<#(NSUInteger)#>] withRowAnimation:<#(UITableViewRowAnimation)#>];//With animation

或重新加载所有没有动画的表：

[self.tableView reloadData];

代替：[tableView beginUpdates];[tableView endUpdates];

需要代码：

  - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {

    if (editingStyle == UITableViewCellEditingStyleDelete) {

    [tableData removeObjectAtIndex:indexPath.row];
[arrayA setValue:tableData ForKey:@"Hostname"];
        [arrayA writeToFile:plistPath atomically: TRUE];
        [self.tableView reloadSections:[NSIndexSet  indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationFade];

    }
    }