How to change button image added to TableView section header

问题

I've added a button to section header which shows a view on clicking it. My need is that I've to show an "Up-arrow" image while view is shown and "Down-arrow" image when view is hidden.

How can I achieve this? Please help me ...

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section{
    UIButton *btn=[UIButton buttonWithType:UIButtonTypeCustom];
            [btn setFrame:CGRectMake(0, 0, 316, 60)];
            [btn setTag:section];
            [aView addSubview:btn];
            [btn addTarget:self action:@selector(sectionTapped:) forControlEvents:UIControlEventTouchDown];
            btn.backgroundColor=[UIColor clearColor];

}

回答1:

I will suggest that you can have 2 images - 1 for 'Up' and 1 for 'Down' arrow. Set default image to the btn for state UIControlStateNormal and set the other image for state UIControlStateSelected. Now in your sectionTapped: method just change the state of the button. So when you show or hide your view you need to set the button selected YES/NO.

Hope this helps.

回答2:

I had done this before in one of my app.

Take this code as Reference

1.Specific Method.

- (void)methodName:(UIButton *)sender
 {
 int i = [sender.titleLabel.text intValue];
 NSNumber *numb;
if(i == 0)
{
    numb = [NSNumber numberWithBool:NO];
   sender.titleLabel.text = @"1";
   [sender setImage:[UIImage imageNamed:@"down.png"] forState:UIControlStateNormal];
   [sender setImage:[UIImage imageNamed:@"up.png"] forState:UIControlStateHighlighted];
 }
else
{
numb = [NSNumber numberWithBool:YES];
sender.titleLabel.text = @"0";
[sender setImage:[UIImage imageNamed:@"up.png"] forState:UIControlStateNormal];
[sender setImage:[UIImage imageNamed:@"down.png"] forState:UIControlStateHighlighted];
}
}

2.Setting UIButton Programatically in UITabelview viewForHeaderInSection.

 UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(240, 20, 30, 30)];

[button addTarget:self
       action:@selector(methodName:)
 forControlEvents:UIControlEventTouchDown];
 button.tag = section;
 if([[sectionsArray objectAtIndex:section] boolValue])
 {
[button setImage:[UIImage imageNamed:@"up.png"] forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:@"down.png"] forState:UIControlStateHighlighted];
button.titleLabel.text = @"0";
 }
 else
 {
  [button setImage:[UIImage imageNamed:@"down.png"] forState:UIControlStateNormal];
   [button setImage:[UIImage imageNamed:@"up.png"] forState:UIControlStateHighlighted];
  button.titleLabel.text = @"1";
  }

回答3:

You can trying using BOOL to check if the button has been pressed or not and animate to rotate the image in your button to point up or down.

-(IBAction)dropdownBtnClicked:(id)sender 
{

      [UIView beginAnimations:nil context:NULL];

      [UIView setAnimationDuration:0.5];

      if (!isDropdownEnabled) 
      { 
         //BOOL - checking if the button has been pressed or not

          isDropdownEnabled=TRUE;
          drpDwnBtn.transform=CGAffineTransformMakeRotation(270/180*M_PI);
      }

      else 
      {

          isDropdownEnabled=FALSE;

          drpDwnBtn.transform=CGAffineTransformMakeRotation(0);

       }

      [UIView commitAnimations];

  }

来源：https://stackoverflow.com/questions/16229910/how-to-change-button-image-added-to-tableview-section-header

标签

ios

uitableview

uibutton