objective-c - 在UIButton中实现切换功能

我想知道如何将切换功能添加到UIButton中，就像用户点击未选择的按钮一样，该按钮变为选中状态并保持选中状态，直到用户通过像以前一样使未选中状态再次点击它为止。

我正在考虑制作一个IBAction，将其从未选中更改为选中，我该怎么做？

这是我尝试过的:

-(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];
    }
}

最佳答案

- (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];
    }

}

您的toggleFav代码没有多大意义。if (favButton == nil) {检查是否存在favButton。但是，如果您要与IB进行连接，那它应该一直在那儿。如果不是，按钮怎么会调用此方法？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];
    }
}

Here，您将找到一个带有DetaiView的示例项目，其中包含一个带有2个状态的Button。
注意:我正在保存在NSUserDefaults中选择了哪个按钮的信息。你不应该那样做。相反，您需要将其保存在模型中。但是由于我没有关于您的模型的信息，因此我仅使用NSUserDefaults。

关于objective-c - 在UIButton中实现切换功能，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/4208364/