Question

如果这看起来很模糊，我很抱歉，但我不确定如何说出来。

我正在尝试构建一个ipad应用程序，让用户使用他们需要的工具填充工作区。我需要一个让用户将组件拖放到app界面的示例。因此，例如，如果我有一个应用程序，用户可以制作一个表单，我希望用户能够拖动文本框，列表，单选按钮等来制作表单，我将如何去做呢？我正在使用的项目将在弹出菜单中，以便用户拖动，然后将在弹出窗口中看到我需要的所有项目。我只是不确定如何让他们从弹出窗口拖动到画布，也能够重复使用相同的项目（因此在示例中有3或4个文本框）。这可能吗？任何人都可以指导我这方面的教程吗？我已经搜索但无法找到任何东西。

如果这是错误的或者是一个愚蠢的任务请告诉我怎么做，这是我第一次在这里发帖。

谢谢

Answer 1

解释这个问题已有很多答案。基本上你可以制作自定义UIView，触摸后会跟随触摸运动。像这样：

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    _originalPosition = self.view.center;
    _touchOffset = CGPointMake(self.view.center.x-position.x,self.view.center.y-position.y);
}

-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{        
    UITouch *touch = [touches anyObject];
    CGPoint position = [touch locationInView: self.view.superview];

    [UIView animateWithDuration:.001
                          delay:0.0
                        options:UIViewAnimationOptionCurveEaseInOut
                     animations:^ {

                         self.view.center = CGPointMake(position.x+_touchOffset.x, position.y+_touchOffset.y);
                     }
                     completion:^(BOOL finished) {}];
}

-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    CGPoint positionInView = [touch locationInView:self.view];
    CGPoint newPosition;
    if (CGRectContainsPoint(_desiredView.frame, positionInView)) {
        newPosition = positionInView;
        // _desiredView is view where the user can drag the view
    } else {
        newPosition = _originalPosition;
        // its outside the desired view so lets move the view back to start position
    }

    [UIView animateWithDuration:0.4
                          delay:0.0
                        options:UIViewAnimationOptionCurveEaseInOut
                     animations:^ {
                         self.view.center = newPosition
                         // to 
                     }
                     completion:^(BOOL finished) {}];

}

类似问题

iPhone App: implementation of Drag and drop images in UIView

Basic Drag and Drop in iOS

iPhone drag/drop

Answer 2

从问题i中你要建立一个像大多数购物应用程序中添加到购物车的功能，如亚马逊，翻转卡丁车等。

- (void)viewDidLoad {
    [super viewDidLoad];

    shoeImageView1 = [[UIImageView alloc]initWithFrame:CGRectMake(46,222, 51 , 51)];
    shoeImageView1.image = [UIImage imageNamed:@"shoe.png"];

    shoeImageView2 = [[UIImageView alloc]initWithFrame:CGRectMake(150,222, 51 , 51)];
    shoeImageView2.image = [UIImage imageNamed:@"shoe1.png"];

    shoeImageView3 = [[UIImageView alloc]initWithFrame:CGRectMake(225,222, 51 , 51)];
    shoeImageView3.image = [UIImage imageNamed:@"shoe2.png"];


     addTOCart = [[UIImageView alloc]initWithFrame:CGRectMake(132,400, 80, 80)];
    addTOCart.image = [UIImage imageNamed:@"basket.png"];
    [self.view addSubview:addTOCart];

    imageViewArray = [[NSMutableArray alloc]initWithObjects: shoeImageView1,shoeImageView2 ,shoeImageView3,nil];



    for (int i=0; i<imageViewArray.count; i++) {

        [self.view addSubview:[imageViewArray objectAtIndex:i]];
        [[imageViewArray objectAtIndex:i]setUserInteractionEnabled:YES];

//[self touchesBegan:imageViewArray[i] withEvent:nil];


    }


}


-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
for(int i=0 ; i< imageViewArray.count; i++)
{

    CGPoint pt = [[touches anyObject]locationInView:self.view];

    startLocation = pt;



    newtemp = [imageViewArray objectAtIndex:i];

    UITouch* bTouch = [touches anyObject];

    if ([bTouch.view isEqual:newtemp])
    {
        firstTouchPoint = [bTouch locationInView:[self view]];
        oldX = firstTouchPoint.x - [[bTouch view]center].x;
        oldY = firstTouchPoint.y - [[bTouch view]center].y;
    }

}
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    for(int i=0 ; i< imageViewArray.count; i++)
    {
    newtemp = [imageViewArray objectAtIndex:i];

        //oldLoc = newtemp.frame;


    if (CGRectContainsPoint(addTOCart.frame , newtemp.frame.origin))
    {
        NSLog(@"touched");
               dragging = NO;

        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Cart" message:@"Added to Cart" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];

        [[imageViewArray objectAtIndex:i] setImage:[UIImage imageNamed:@""]];


        [imageViewArray removeObjectAtIndex:i];

        [alert show];


        break;

    }

    else
    {
        //[newtemp setCenter:CGPointMake(startLocation.x-oldX, startLocation.y-oldY)];
    }
       // self.view.userInteractionEnabled= NO;

    }


    dragging = NO;
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{

    UITouch* mTouch = [touches anyObject];
   // if ([mTouch.view isEqual: newtemp]) {
        CGPoint cp = [mTouch locationInView:[self view]];
        [[mTouch view]setCenter:CGPointMake(cp.x-oldX, cp.y-oldY)];


   // }
}

您可以使用这些代码来实现这些功能。使用这些代码，您可以将对象拖动到屏幕中的任何位置。

对于示例项目，您可以使用this链接。

将拖放组件添加到iOS应用程序

2 个答案: