Android动画下拉/上视图正确

好的，我正在做一个适当的向下滑动动画。向下滑动的视图应以一个平滑的运动将其下方的所有视图向下推，再次，当其向上滑动时，所有视图应以一个平滑的运动跟随

我所尝试的： 代码：

LinearLayout lin = (LinearLayout)findViewById(R.id.user_list_container);
                setLayoutAnimSlidedownfromtop(lin, this);
                lin.addView(getLayoutInflater().inflate(R.layout.user_panel,null),0);

以及：

My user_panel.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="40dp"
    android:orientation="vertical" >
    <ImageView 
        android:layout_alignParentLeft="true"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:src="@drawable/icon" />
</LinearLayout>

主xml的顶部：

<LinearLayout
        android:id="@+id/user_list_container"
        android:layout_alignParentTop="true"
        android:orientation="vertical" 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>
    <LinearLayout
        android:id="@+id/container"
        android:layout_below="@+id/user_list_container"
        android:orientation="vertical" 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">

---

上述方法的问题是，当我首先启动动画时，会创建视图的空白空间，然后视图向下滑动。我希望它能慢慢地向下推所有其他视图，而不是一个硬动作。

因此，我在以下人员的帮助下完成了这项工作：。 如果是安卓3.0（），我可以使用属性动画，但不是这样，我必须自己做

以下是我的结论：

import android.view.View;
import android.view.animation.Animation;
import android.view.animation.Transformation;

/**
 * Class for handling collapse and expand animations.
 * @author Esben Gaarsmand
 *
 */
public class ExpandCollapseAnimation extends Animation {
    private View mAnimatedView;
    private int mEndHeight;
    private int mType;

    /**
     * Initializes expand collapse animation, has two types, collapse (1) and expand (0).
     * @param view The view to animate
     * @param duration
     * @param type The type of animation: 0 will expand from gone and 0 size to visible and layout size defined in xml. 
     * 1 will collapse view and set to gone
     */
    public ExpandCollapseAnimation(View view, int duration, int type) {
        setDuration(duration);
        mAnimatedView = view;
        mEndHeight = mAnimatedView.getLayoutParams().height;
        mType = type;
        if(mType == 0) {
            mAnimatedView.getLayoutParams().height = 0;
            mAnimatedView.setVisibility(View.VISIBLE);
        }
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);
        if (interpolatedTime < 1.0f) {
            if(mType == 0) {
                mAnimatedView.getLayoutParams().height = (int) (mEndHeight * interpolatedTime);
            } else {
                mAnimatedView.getLayoutParams().height = mEndHeight - (int) (mEndHeight * interpolatedTime);
            }
            mAnimatedView.requestLayout();
        } else {
            if(mType == 0) {
                mAnimatedView.getLayoutParams().height = mEndHeight;
                mAnimatedView.requestLayout();
            } else {
                mAnimatedView.getLayoutParams().height = 0;
                mAnimatedView.setVisibility(View.GONE);
                mAnimatedView.requestLayout();
                mAnimatedView.getLayoutParams().height = mEndHeight;
            }
        }
    }
}

xml:

---

谢谢你！这是一个非常有用的答案。在我的例子中，我只是尝试用包裹内容的高度设置视图的动画。我尝试了triggs的两行建议，但在我的情况下不起作用。（我没有花太多时间去寻找原因。）我最终使用了Warpzit的

ExpandCollapseAnimation

的一种稍加修改的形式和他的静态方法来确定视图的高度

稍微详细一点：

我将他的静态方法

setHeightForWrapContent（）

包含在

ExpandCollapseAnimation

类中

我在

ExpandCollapseAnimation

构造函数中调用

setHeightForWrapContent（）

，以正确确定视图的高度。为此，我必须将活动与构造函数一起传递

在

applyTransformation（）

方法中，当视图最终降低到零高度时，我将视图的高度返回到wrap\u内容。如果不执行此操作，并在以后更改视图的内容，则展开视图时，视图将展开到先前确定的高度

代码在这里：

public class ExpandCollapseAnimation extends Animation {
    private View mAnimatedView;
    private int mEndHeight;
    private int mType;

    public ExpandCollapseAnimation(View view, int duration, int type, Activity activity) {
        setDuration(duration);
        mAnimatedView = view;

        setHeightForWrapContent(activity, view);

        mEndHeight = mAnimatedView.getLayoutParams().height;

        mType = type;
        if(mType == 0) {
            mAnimatedView.getLayoutParams().height = 0;
            mAnimatedView.setVisibility(View.VISIBLE);
        }
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);
        if (interpolatedTime < 1.0f) {
            if(mType == 0) {
                mAnimatedView.getLayoutParams().height = (int) (mEndHeight * interpolatedTime);
            } else {
                mAnimatedView.getLayoutParams().height = mEndHeight - (int) (mEndHeight * interpolatedTime);
            }
            mAnimatedView.requestLayout();
        } else {
            if(mType == 0) {
                mAnimatedView.getLayoutParams().height = mEndHeight;
                mAnimatedView.requestLayout();
            } else {
                mAnimatedView.getLayoutParams().height = 0;
                mAnimatedView.setVisibility(View.GONE);
                mAnimatedView.requestLayout();
                mAnimatedView.getLayoutParams().height = LayoutParams.WRAP_CONTENT;     // Return to wrap
            }
        }
    }

    public static void setHeightForWrapContent(Activity activity, View view) {
        DisplayMetrics metrics = new DisplayMetrics();
        activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);

        int screenWidth = metrics.widthPixels;

        int heightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        int widthMeasureSpec = MeasureSpec.makeMeasureSpec(screenWidth, MeasureSpec.EXACTLY);

        view.measure(widthMeasureSpec, heightMeasureSpec);
        int height = view.getMeasuredHeight();
        view.getLayoutParams().height = height;
    }
}

public类ExpandCollapseAnimation扩展动画{
私人视图mAnimatedView；
私家车高度；
私有int-mType；
公共ExpandCollapseAnimation（视图、整型持续时间、整型类型、活动）{
设置持续时间（持续时间）；
mAnimatedView=视图；
设置WrapContent（活动、视图）的高度；
mEndHeight=mAnimatedView.getLayoutParams（）.height；
mType=类型；
如果（mType==0）{
mAnimatedView.getLayoutParams（）.height=0；
mAnimatedView.setVisibility（View.VISIBLE）；
}
}
@凌驾
受保护的无效应用转换（浮点插值时间，转换t）{
超级应用转换（插值时间，t）；
如果（插值时间<1.0f）{
如果（mType==0）{
mAnimatedView.getLayoutParams（）.height=（int）（mEndHeight*interpolatedTime）；
}否则{
mAnimatedView.getLayoutParams（）.height=mEndHeight-（int）（mEndHeight*interpolatedTime）；
}
mAnimatedView.requestLayout（）；
}否则{
如果（mType==0）{
mAnimatedView.getLayoutParams（）.height=mEndHeight；
mAnimatedView.requestLayout（）；
}否则{
mAnimatedView.getLayoutParams（）.height=0；
mAnimatedView.setVisibility（View.GONE）；
mAnimatedView.requestLayout（）；
mAnimatedView.getLayoutParams（）.height=LayoutParams.WRAP\u CONTENT；//返回到WRAP
}
}
}
公共静态void setHeightForWrapContent（活动、视图）{
DisplayMetrics=新的DisplayMetrics（）；
activity.getWindowManager（）.getDefaultDisplay（）.getMetrics（度量）；
int screenWidth=metrics.widthPixels；
int heightMeasureSpec=MeasureSpec.MakeMasureSpec（0，MeasureSpec.Unspected）；
int-widthmasurespec=MeasureSpec.makeMeasureSpec（屏幕宽度，精确测量）；
视图测量（宽度测量、高度测量）；
int height=view.getMeasuredHeight（）；
view.getLayoutParams（）.height=高度；
}
}

---

再次感谢你，沃普齐特

我认为您需要查看

LayoutTransition

类。它提供了在布局中添加/删除视图的动画机制。确定forcer高度元素。但不幸的是，此方法不适用于包裹内容元素：（@bixi实际上是这样，您只需计算包裹内容的高度。这是可行的（做了但找不到引用quick=/，如果需要请告诉我）很好的示例！您还可以重用View.VISIBLE和View.Goe以指示类型（动画结果）将

mEndHeight=mAnimatedView.getLayoutParams（）.height；

替换为

mEndHeight=type==0？mAnimatedView.getLayoutParams（）.height:mAnimatedView.getMeasuredHeight（）；

并且它将使用

包装内容

，而不需要额外的方法

setHeightForWrapContent（活动，视图）

Oh，还需要

if（mEndHeight<0）mEndHeight=mAnimatedView.getMeasuredHeight（）；

（如果视图开始最小化，则没有它

mEndHeight

将为-2）

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class AnimationTestActivity extends Activity {
    private boolean mActive = false;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final Button animatedButton = (Button) findViewById(R.id.animatedButton);

        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                ExpandCollapseAnimation animation = null;
                if(mActive) {
                    animation = new ExpandCollapseAnimation(animatedButton, 1000, 1);
                    mActive = false;
                } else {
                    animation = new ExpandCollapseAnimation(animatedButton, 1000, 0);
                    mActive = true;
                }
                animatedButton.startAnimation(animation);
            }
        });
    }
}

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <Button
        android:id="@+id/animatedButton"
        android:visibility="gone"
        android:layout_width="fill_parent"
        android:layout_height="50dp"
        android:text="@string/hello"/>
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <Button
        android:id="@+id/button"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello"/>
</LinearLayout>

/**
 * This methode can be used to calculate the height and set it for views with wrap_content as height. 
 * This should be done before ExpandCollapseAnimation is created.
 * @param activity
 * @param view
 */
public static void setHeightForWrapContent(Activity activity, View view) {
    DisplayMetrics metrics = new DisplayMetrics();
    activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);

    int screenWidth = metrics.widthPixels;

    int heightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
    int widthMeasureSpec = MeasureSpec.makeMeasureSpec(screenWidth, MeasureSpec.EXACTLY);

    view.measure(widthMeasureSpec, heightMeasureSpec);
    int height = view.getMeasuredHeight();
    view.getLayoutParams().height = height;
}

public class ExpandCollapseAnimation extends Animation {
    private View mAnimatedView;
    private int mEndHeight;
    private int mType;

    public ExpandCollapseAnimation(View view, int duration, int type, Activity activity) {
        setDuration(duration);
        mAnimatedView = view;

        setHeightForWrapContent(activity, view);

        mEndHeight = mAnimatedView.getLayoutParams().height;

        mType = type;
        if(mType == 0) {
            mAnimatedView.getLayoutParams().height = 0;
            mAnimatedView.setVisibility(View.VISIBLE);
        }
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);
        if (interpolatedTime < 1.0f) {
            if(mType == 0) {
                mAnimatedView.getLayoutParams().height = (int) (mEndHeight * interpolatedTime);
            } else {
                mAnimatedView.getLayoutParams().height = mEndHeight - (int) (mEndHeight * interpolatedTime);
            }
            mAnimatedView.requestLayout();
        } else {
            if(mType == 0) {
                mAnimatedView.getLayoutParams().height = mEndHeight;
                mAnimatedView.requestLayout();
            } else {
                mAnimatedView.getLayoutParams().height = 0;
                mAnimatedView.setVisibility(View.GONE);
                mAnimatedView.requestLayout();
                mAnimatedView.getLayoutParams().height = LayoutParams.WRAP_CONTENT;     // Return to wrap
            }
        }
    }

    public static void setHeightForWrapContent(Activity activity, View view) {
        DisplayMetrics metrics = new DisplayMetrics();
        activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);

        int screenWidth = metrics.widthPixels;

        int heightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        int widthMeasureSpec = MeasureSpec.makeMeasureSpec(screenWidth, MeasureSpec.EXACTLY);

        view.measure(widthMeasureSpec, heightMeasureSpec);
        int height = view.getMeasuredHeight();
        view.getLayoutParams().height = height;
    }
}