如何在xcode上的单视图应用程序中创建一个带按钮的d-pad

Question

我看过并找到了制作带按钮的d-pad的代码，但你必须不断点击按钮才能使其工作。所以，如果你想上去，你必须不断地向上按压。如何在用户按下按钮的情况下使对象移动。这是我已经的按钮代码

-(IBAction)moveLeft:(id)sender{
Robot.center = CGPointMake(Robot.center.x-10, Robot.center.y);
[UIView animateWithDuration:0.5 animations:^{
    Robot.center = CGPointMake(Robot.center.x, Robot.center.y+10);
}];
}
-(IBAction)moveRight:(id)sender{
Robot.center = CGPointMake(Robot.center.x+10, Robot.center.y);
[UIView animateWithDuration:0.5 animations:^{
    Robot.center = CGPointMake(Robot.center.x, Robot.center.y+10);
}];
}
-(IBAction)moveUp:(id)sender{
Robot.center = CGPointMake(Robot.center.x, Robot.center.y-10);
[UIView animateWithDuration:0.5 animations:^{
    Robot.center = CGPointMake(Robot.center.x, Robot.center.y+10);
 }];
}
-(IBAction)moveDown:(id)sender{
Robot.center = CGPointMake(Robot.center.x, Robot.center.y+10);
[UIView animateWithDuration:0.5 animations:^{
    Robot.center = CGPointMake(Robot.center.x, Robot.center.y+10);
}];
}

Answer 1

您可以使用UIControlEventTouchDown控制事件来启动方法运行，使用UIControlEventTouchUpInside或类似事件来检测按钮何时不再"按下"。

设置按钮的操作，例如：

[myButton addTarget:self action:@selector(startButtonTouch:) forControlEvents:UIControlEventTouchDown];
[myButton addTarget:self action:@selector(endButtonTouch:) forControlEvents:UIControlEventTouchUpInside | UIControlEventTouchUpOutside];

（请注意，以上内容将导致按钮内外的触摸，以调用endButtonTouch:方法。）

然后添加startButtonTouch:和endButtonTouch方法，例如：

- (void)startButtonTouch:(id)sender {
    // start the process running...
}
- (void)endButtonTouch:(id)sender {
// stop the running process...
}

如果您想在用户拖动到按钮外部时结束它，也可以添加UIControlEventTouchDragExit。

Answer 2

设置按钮上下状态：

- (IBAction)touchUpIn_btnUp:(id)sender {
    self.buttonUpIsDown = NO;
}
- (IBAction)touchDownIn_btnUp:(id)sender {
    self.buttonUpIsDown = YES;
}
- (IBAction)touchUpIn_btnLeft:(id)sender {
    self.buttonLeftIsDown = NO;
}
- (IBAction)touchDownIn_btnLeft:(id)sender {
    self.buttonLeftIsDown = YES;
}
- (IBAction)touchUpIn_btnRight:(id)sender {
    self.buttonRightIsDown = NO;
}
- (IBAction)touchDownIn_btnRight:(id)sender {
    self.buttonRightIsDown = YES;
}
- (IBAction)touchUpIn_btnDown:(id)sender {
    self.buttonDownIsDown = NO;
}
- (IBAction)touchDownIn_btnDown:(id)sender {
    self.buttonDownIsDown = YES;
}

检查循环中的状态

- (void) updateControls {
    if (self.buttonUpIsDown) {
        // move up
    }
    if (self.buttonDownIsDown) {
        // move down
    }
    if (self.buttonLeftIsDown) {
        // move left
    }
    if (self.buttonRightIsDown) {
        // move right
    }
}

调用循环：

[NSTimer scheduledTimerWithTimeInterval:MAIN_LOOP_TIME target:self selector:@selector(updateControls) userInfo:nil repeats:YES];