我正在尝试创建一个简单的程序,它上面有一个按钮和一个隐藏按钮。当用户单击第一个按钮时,第二个按钮将使用平滑动画显示。当用户再次单击第一个按钮时,第二个按钮会平滑消失,等等。我正在使用Alpha Animation为显示和消失的操作设置动画,但我遇到了以下问题:
第一次时间我点击按钮,没有任何反应。当我再次单击该按钮时,它会出现,然后立即消失。当我点击按钮第三次时,它会平滑地动画"淡入"运动。然后,当我第四次点击它时,它可以平滑地激活"淡出"动作等...
以下是这个简单程序中的代码:
public class MainActivity extends AppCompatActivity {
public Button toggleButton;
public Button helloButton;
public boolean isVisible = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
helloButton = (Button)findViewById(R.id.helloButton);
toggleButton = (Button)findViewById(R.id.toggleButton);
toggleButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (!isVisible) {
//helloButton.setVisibility(View.VISIBLE);
AlphaAnimation fadeInAnimation = new AlphaAnimation(0, 1); // start alpha, end alpha
fadeInAnimation.setDuration(250); // time for animation in milliseconds
fadeInAnimation.setFillAfter(true); // make the transformation persist
fadeInAnimation.setAnimationListener(new Animation.AnimationListener() {
@Override
public void onAnimationEnd(Animation animation) {
helloButton.setVisibility(View.VISIBLE);
}
@Override
public void onAnimationRepeat(Animation animation) { }
@Override
public void onAnimationStart(Animation animation) {
helloButton.setVisibility(View.GONE);
}
});
helloButton.startAnimation(fadeInAnimation);
isVisible = true;
System.out.println("Button is invisible... Time to Fade IN");
}
else {
//helloButton.setVisibility(View.GONE);
AlphaAnimation fadeOutAnimation = new AlphaAnimation(1, 0); // start alpha, end alpha
fadeOutAnimation.setDuration(250); // time for animation in milliseconds
fadeOutAnimation.setFillAfter(true); // make the transformation persist
fadeOutAnimation.setAnimationListener(new Animation.AnimationListener() {
@Override
public void onAnimationEnd(Animation animation) {
helloButton.setVisibility(View.GONE);
}
@Override
public void onAnimationRepeat(Animation animation) { }
@Override
public void onAnimationStart(Animation animation) {
helloButton.setVisibility(View.VISIBLE);
}
});
helloButton.startAnimation(fadeOutAnimation);
isVisible = false;
System.out.println("Button is visible... Time to Fade OUT");
}
}
});
}
}
我觉得这很简单;然而,这是我第一次在Android开发中遇到过动画。任何建议和意见将不胜感激!
答案 0 :(得分:2)
您不需要变量isVisible
,只需检查按钮是否可见。
要首先查看fadeInAnimation
,您需要使视图可见。
我也更改了两个动画的持续时间,请检查此代码:
helloButton = findViewById(R.id.helloButton);
toggleButton = findViewById(R.id.toggleButton);
toggleButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (helloButton.getVisibility() == View.GONE) {
AlphaAnimation fadeInAnimation = new AlphaAnimation(0, 1);
fadeInAnimation.setDuration(2500);
fadeInAnimation.setFillAfter(true);
fadeInAnimation.setAnimationListener(new Animation.AnimationListener() {
@Override
public void onAnimationEnd(Animation animation) {
}
@Override
public void onAnimationRepeat(Animation animation) { }
@Override
public void onAnimationStart(Animation animation) {
helloButton.setVisibility(View.VISIBLE);
}
});
helloButton.startAnimation(fadeInAnimation);
} else {
AlphaAnimation fadeOutAnimation = new AlphaAnimation(1, 0);
fadeOutAnimation.setDuration(2500);
fadeOutAnimation.setFillAfter(true);
fadeOutAnimation.setAnimationListener(new Animation.AnimationListener() {
@Override
public void onAnimationEnd(Animation animation) {
helloButton.setVisibility(View.GONE);
}
@Override
public void onAnimationRepeat(Animation animation) { }
@Override
public void onAnimationStart(Animation animation) {
}
});
helloButton.startAnimation(fadeOutAnimation);
}
}
});