我有一个线性布局,我想显示或隐藏与动画,推动布局向上或向下每当我改变其可见性。

我在那里看过一些样品,但没有一个适合我的需要。

我已经为动画创建了两个xml文件,但我不知道当我改变线性布局的可见性时如何启动它们。


当前回答

最简单的解决方案:在持有视图的容器上设置android:animateLayoutChanges="true"。

如果你有一个如下所示的布局,这个容器中所有视图的可见性变化都将自动动画化。

<LinearLayout android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:animateLayoutChanges="true"
    >

    <Views_which_change_visibility>

</LinearLayout>

你可以在动画布局变化- Android开发者上找到更多细节

其他回答

使用这个类:

public class ExpandCollapseExtention {

 public static void expand(View view) {
    view.setVisibility(View.VISIBLE);

    final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    view.measure(widthSpec, heightSpec);

    ValueAnimator mAnimator = slideAnimator(view, 0, view.getMeasuredHeight());
    mAnimator.start();
}


public static void collapse(final View view) {
    int finalHeight = view.getHeight();

    ValueAnimator mAnimator = slideAnimator(view, finalHeight, 0);

    mAnimator.addListener(new Animator.AnimatorListener() {

        @Override
        public void onAnimationEnd(Animator animator) {               
            view.setVisibility(View.GONE);
        }


        @Override
        public void onAnimationStart(Animator animation) {

        }


        @Override
        public void onAnimationCancel(Animator animation) {

        }


        @Override
        public void onAnimationRepeat(Animator animation) {

        }
    });
    mAnimator.start();
}


private static ValueAnimator slideAnimator(final View v, int start, int end) {

    ValueAnimator animator = ValueAnimator.ofInt(start, end);

    animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {

        @Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {

            int value = (Integer) valueAnimator.getAnimatedValue();
            ViewGroup.LayoutParams layoutParams = v.getLayoutParams();
            layoutParams.height = value;
            v.setLayoutParams(layoutParams);
        }
    });
    return animator;
}
}

最简单的解决方案:在持有视图的容器上设置android:animateLayoutChanges="true"。

如果你有一个如下所示的布局,这个容器中所有视图的可见性变化都将自动动画化。

<LinearLayout android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:animateLayoutChanges="true"
    >

    <Views_which_change_visibility>

</LinearLayout>

你可以在动画布局变化- Android开发者上找到更多细节

Suragch用科特林语回答。这对我很管用。

class MainActivity : AppCompatActivity() {

var isUp: Boolean = false

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    var myView: View = findViewById(R.id.my_view)
    var myButton: Button = findViewById(R.id.my_button)

    //Initialize as invisible
    myView.visibility = View.INVISIBLE
    myButton.setText("Slide up")

    isUp = false

}


fun View.slideUp(duration: Int = 500){
    visibility = View.VISIBLE
    val animate = TranslateAnimation(0f, 0f, this.height.toFloat(), 0f)
    animate.duration = duration.toLong()
    animate.fillAfter = true
    this.startAnimation(animate)
}

fun View.slideDown(duration: Int = 500) {
    visibility = View.VISIBLE
    val animate = TranslateAnimation(0f, 0f, 0f, this.height.toFloat())
    animate.duration = duration.toLong()
    animate.fillAfter = true
    this.startAnimation(animate)
}

fun onSlideViewButtonClick(view: View){
    if(isUp){
        my_view.slideDown()
        my_button.setText("Slide Up")

    }
    else{
        my_view.slideUp()
        my_button.setText("Slide Down")
    }
    isUp = !isUp
}

}

科特林

根据Suragch的回答,下面是一种使用View扩展的优雅方式:

fun View.slideUp(duration: Int = 500) {
    visibility = View.VISIBLE
    val animate = TranslateAnimation(0f, 0f, this.height.toFloat(), 0f)
    animate.duration = duration.toLong()
    animate.fillAfter = true
    this.startAnimation(animate)
}

fun View.slideDown(duration: Int = 500) {
    visibility = View.VISIBLE
    val animate = TranslateAnimation(0f, 0f, 0f, this.height.toFloat())
    animate.duration = duration.toLong()
    animate.fillAfter = true
    this.startAnimation(animate)
}

然后无论你想在哪里使用它,你只需要myview。slideup()或myview。slidedown ()

我有一个角落的情况,我的视图高度仍然是0所以。

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.view.View;

public final class AnimationUtils {

  public static void slideDown(final View view) {
        view.animate()
                .translationY(view.getHeight())
                .alpha(0.f)
                .setListener(new AnimatorListenerAdapter() {
                    @Override
                    public void onAnimationEnd(Animator animation) {
                        // superfluous restoration
                        view.setVisibility(View.GONE);
                        view.setAlpha(1.f);
                        view.setTranslationY(0.f);
                    }
                });
    }

    public static void slideUp(final View view) {
        view.setVisibility(View.VISIBLE);
        view.setAlpha(0.f);

        if (view.getHeight() > 0) {
            slideUpNow(view);
        } else {
            // wait till height is measured
            view.post(new Runnable() {
                @Override
                public void run() {
                    slideUpNow(view);
                }
            });
        }
    }

    private static void slideUpNow(final View view) {
        view.setTranslationY(view.getHeight());
        view.animate()
                .translationY(0)
                .alpha(1.f)
                .setListener(new AnimatorListenerAdapter() {
                    @Override
                    public void onAnimationEnd(Animator animation) {
                        view.setVisibility(View.VISIBLE);
                        view.setAlpha(1.f);
                    }
                });
    }

}