在UIButton中实现切换功能

Question

我想知道如何将切换功能添加到a UIButton,就像用户点击一个未选中的按钮一样,按钮被选中并保持选中状态,直到用户再次点击它为止,就像之前一样.

我正在考虑制作一个IBAction将其从未选中更改为选中的,我该怎么做？

继承人我试过的:

-(IBAction)toggle {

    //Toggle on implementation.

        button.selected = YES;
        button.highlighted = NO;
        button.enabled = YES;

    //Toggle off implementation.

    if (button.highlighted == YES) {

        button.selected = NO;
        button.highlighted = YES;
        button.enabled = NO;
    }
}

问题...

-(IBAction)toggleFav {

    if (favButton == nil) {

        UIImage *unselectedImage = [UIImage imageNamed:@"favUntapped.png"];
        UIImage *selectedImage = [UIImage imageNamed:@"favTapped.png"];
        [favButton setImage:unselectedImage forState:UIControlStateNormal];
        [favButton setImage:selectedImage forState:UIControlStateSelected];
        [favButton setFrame:CGRectMake(0, 0, 40, 40)];
    }       

    if([favButton isSelected]){

        //Add to menu.
        [favButton setSelected:NO];
    } else {

        //Remove from menu.

        [favButton setSelected:YES];
    }
}

Answer 1

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

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
        UIImage *unselectedImage = [UIImage imageNamed:@"unselected.png"];
        UIImage *selectedImage = [UIImage imageNamed:@"selected.png"];
        UIButton *b = [UIButton buttonWithType:UIButtonTypeCustom];
        [b setBackgroundImage:unselectedImage forState:UIControlStateNormal];
        [b setBackgroundImage:selectedImage forState:UIControlStateSelected];
        [b addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
        [b setFrame:CGRectMake(0, 0, 40, 40)];
        [cell.contentView addSubview:b];
    }       
    return cell;
}

-(void) buttonPressed:(UIButton *)sender
{
    if([sender isSelected]){
        //...
        [sender setSelected:NO];
    } else {
        //...    
        [sender setSelected:YES];
    }

}

编辑
您的toggleFav代码没有多大意义.
if (favButton == nil) {检查,如果favButton存在.但是如果你将它与IB连接起来,它应该始终存在于那里.如果不是,那么按钮如何调用此方法？所以这样做:

-(void)viewDidLoad
{
    //....
    UIImage *unselectedImage = [UIImage imageNamed:@"favUntapped.png"];
    UIImage *selectedImage = [UIImage imageNamed:@"favTapped.png"];
    [favButton setImage:unselectedImage forState:UIControlStateNormal];
    [favButton setImage:selectedImage forState:UIControlStateSelected];
    [favButton setFrame:CGRectMake(0, 0, 40, 40)];
    //....
}


-(IBAction)toggleFav:(UIButton *)sender {
    if([sender isSelected]){
        //...
        [sender setSelected:NO];
    } else {
        //...    
        [sender setSelected:YES];
    }
}

编辑
在这里,您将找到一个带有DetaiView的示例项目,它包含一个具有2个状态的Button.
注意:我正在保存NSUserDefaults中选择的按钮的信息.你不应该这样做.相反,您需要将其保存在模型中.但由于我没有关于你的模型的信息,我只是使用NSUserDefaults.