How To Create Simple TableView Part 2

How To Create Simple TableView Part 2

On 08.27.09, In GUI, by Jonathan Crowe

TableView (Part 2)

In this tutorial you will learn how to capture the events on clicking the rows of the table. Table isn’t just used to preset the data but it is often needed to do some action against the selection of a cell.

Here is an overview of the part 1, how Table view is created.

1) Declare the UITableView variable and map it to the actual table in interface builder.

2) Implement UITableViewDelegate and UITableViewDataSource protocols.

3) Assign delegate and data source to UITableView object.

4) Implement numberOfRowsInSection and cellForRowAtIndexPath datasource methods as follows:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
 
return4;
 
}- (UITableViewCell *)tableView:(UITableView *)ttableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *MyIdentifier = @"MyIdentifier";
//If a cell with this identifier already created then it will be reused
UITableViewCell *cell = [ttableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (!cell) {
//If a cell with this identifier doesn't already created then it will be created and assigned an identofier
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:MyIdentifier] autorelease];
}
 
// Index of the cell to be processed
int index = indexPath.row;
 
// Text is going to be set of the cell
cell.text = [NSStringstringWithFormat:@"%i", index];
 
// Cell is returned which will be shown on table
return cell;
}

Now you will learn about another method named didSelectRowAtIndexPath which is called everytime when user select a cell. You have to implement this method in the same controller class. Following is a basic implementation of this methos which will show an alert to the user saying “Row# n is selected”.

-(void)tableView: (UITableView*) ttableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
//Message to show. indexPath.row is the row number selected
NSString* msg = [NSStringstringWithFormat:@"Row# %i is selected", indexPath.row];
// Creating an alert view with the message above
UIAlertView *alertmsg = [[UIAlertViewalloc] initWithTitle:@"title"message:msg delegate:selfcancelButtonTitle:@"OK"otherButtonTitles:nil];
// Show the alert
[alertmsg show];
// Releae the alert
alertmsg release];
}

Now when a user will select any row an alert message will be shown. You can do in this method what ever you want according to your need. Following out put will be shown on selection of 2^nd row: