動畫在列表視圖中添加項目和項目移動像谷歌加應用程序

Question

我想重現列表視圖項目，當用戶在列表視圖中滾動時出現的效果。

我想重現與Google Plus應用程序相同的效果。

我該怎麼做？

UPDATE：

這裏是我的代碼在我getView的提取物（）：

final float centerX = rowView.getWidth()/2.0f; 
    final float centerY = rowView.getHeight()/2.0f; 

    rowView.startAnimation(new Rotate3dAnimation(0.0f, -90.0f, centerX, centerY, 310.0f, true)); 

更新2：

02-12 16:01:17.198: E/AndroidRuntime(21625): java.lang.NullPointerException 
02-12 16:01:17.198: E/AndroidRuntime(21625): at com.rss.home.ArticleListAdapterHome.getView(ArticleListAdapterHome.java:129) 
02-12 16:01:17.198: E/AndroidRuntime(21625): at android.widget.AbsListView.obtainView(AbsListView.java:2263) 
02-12 16:01:17.198: E/AndroidRuntime(21625): at android.widget.ListView.makeAndAddView(ListView.java:1790) 
02-12 16:01:17.198: E/AndroidRuntime(21625): at android.widget.ListView.fillDown(ListView.java:691) 
02-12 16:01:17.198: E/AndroidRuntime(21625): at android.widget.ListView.fillFromTop(ListView.java:752) 

Answer 1

感謝您的視頻。
這看起來像一個3D旋轉對我來說。動畫可能從適配器的getView方法開始。這意味着有三個步驟：

1. 檢查定製ListAdapter，例如， here。您還可以找到這樣
2. Click here，看看如何在getView
3. 檢查this answer here啓動動畫了很多問題/答案。它描述了在哪裏可以找到的3D動畫

我沒有檢查的三維動畫自己的例子，但ListAdapter，並在其上Animation不應該是一個大問題。

---

編輯：
您不必從XML載入動畫。你可能不喜歡這樣：

public View getView(int position, View view, ViewGroup viewGroup) { 
    // normal handling 
    // ... 
    // now apply animation 
    view.startAnimation(new Rotate3dAnimation(/*params*/)); 
} 

---

EDIT2：
現在我已經測試它自己，這裏的東西我改變，使其工作：

1. 我忘了把動畫的持續時間，我確實設置了這個
2. 視圖的高度和寬度沒有在getView中設置，所以刪除了參數centerX和centerY並添加View view並賦予它rowView
3. 動畫使用camera.rotateY，但是這需要改變，以camera.rotateX

這是我更新Rotate3dAnimation：

package de.malaka.player.animation; 

import android.view.View; 
import android.view.animation.Animation; 
import android.view.animation.Transformation; 
import android.graphics.Camera; 
import android.graphics.Matrix; 

/** 
* An animation that rotates the view on the Y axis between two specified angles. 
* This animation also adds a translation on the Z axis (depth) to improve the effect. 
*/ 
public class Rotate3dAnimation extends Animation { 
private final float mFromDegrees; 
private final float mToDegrees; 
private final float mDepthZ; 
private final View mView; 
private final boolean mReverse; 
private Camera mCamera; 

/** 
* Creates a new 3D rotation on the Y axis. The rotation is defined by its 
* start angle and its end angle. Both angles are in degrees. The rotation 
* is performed around a center point on the 2D space, definied by a pair 
* of X and Y coordinates, called centerX and centerY. When the animation 
* starts, a translation on the Z axis (depth) is performed. The length 
* of the translation can be specified, as well as whether the translation 
* should be reversed in time. 
* 
* @param fromDegrees the start angle of the 3D rotation 
* @param toDegrees the end angle of the 3D rotation 
* @param centerX the X center of the 3D rotation 
* @param centerY the Y center of the 3D rotation 
* @param reverse true if the translation should be reversed, false otherwise 
*/ 
public Rotate3dAnimation(float fromDegrees, float toDegrees, float depthZ, boolean reverse, View view) { 
    mFromDegrees = fromDegrees; 
    mToDegrees = toDegrees; 
    mDepthZ = depthZ; 
    mReverse = reverse; 
    mView = view; 
} 

@Override 
public void initialize(int width, int height, int parentWidth, int parentHeight) { 
    super.initialize(width, height, parentWidth, parentHeight); 
    mCamera = new Camera(); 
} 

@Override 
protected void applyTransformation(float interpolatedTime, Transformation t) { 
    final float fromDegrees = mFromDegrees; 
    float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime); 

    final float centerX = mView.getWidth()/2; 
    final float centerY = mView.getHeight()/2; 
    final Camera camera = mCamera; 

    final Matrix matrix = t.getMatrix(); 

    camera.save(); 
    if (mReverse) { 
     camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime); 
    } else { 
     camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime)); 
    } 
    camera.rotateX(degrees); 
    camera.getMatrix(matrix); 
    camera.restore(); 

    matrix.preTranslate(-centerX, -centerY); 
    matrix.postTranslate(centerX, centerY); 
} 
} 

這就是我如何在適配器中使用它：

Animation anim = new Rotate3dAnimation(90.0f, 0.0f, 100.0f, false, convertView); 
anim.setDuration(1000l); 
convertView.startAnimation(anim); 

持續時間i現在很長，但這樣你可以調整值。