一说明

这里重要应用类 AutoTextView，这是一个自定义的类，继承至TextSwitcher，下面临 AutoTextView类做简要说明：

1. 该类应用的重点，在于设置两个动画， setInAnimation(...) 和 setOutAnimation(...)，分离是文字进入的动画和文字退出的动画；

2. 类中定义了一个外部类-Rotate3dAnimation，重要靠该类实现文字进出动画，该外部类继承至Animation。说来偶合，这个恰好是在apiDemo中看到了，自定义Animation我还是第一次应用，动画逻辑均在void applyTransformation(float interpolatedTime, Transformation t)中实现，代码相当锋利，我在原来的基础上，更改了一下，实现了上述的效果，

二代码部分：

1.AutoTextView.java

package com.example.animtextview;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Camera;import android.graphics.Matrix;import android.util.AttributeSet;import android.view.Gravity;import android.view.View;import android.view.animation.AccelerateInterpolator;import android.view.animation.Animation;import android.view.animation.Transformation;import android.widget.TextSwitcher;import android.widget.TextView;import android.widget.ViewSwitcher;public class AutoTextView extends TextSwitcher implements		ViewSwitcher.ViewFactory {	private float mHeight;	private Context mContext;	//mInUp,mOutUp分离构成向下翻页的进出动画	private Rotate3dAnimation mInUp;	private Rotate3dAnimation mOutUp;		//mInDown,mOutDown分离构成向下翻页的进出动画	private Rotate3dAnimation mInDown;	private Rotate3dAnimation mOutDown;		public AutoTextView(Context context) {		this(context, null);		// TODO Auto-generated constructor stub	}	public AutoTextView(Context context, AttributeSet attrs) {		super(context, attrs);		// TODO Auto-generated constructor stub		TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.auto3d);		mHeight = a.getDimension(R.styleable.auto3d_textSize, 36);		a.recycle();		mContext = context;		init();	}	private void init() {		// TODO Auto-generated method stub		setFactory(this);		mInUp = createAnim(-90, 0 , true, true);		mOutUp = createAnim(0, 90, false, true);		mInDown = createAnim(90, 0 , true , false);		mOutDown = createAnim(0, -90, false, false);		//TextSwitcher重要用于文件切换，比如 从文字A 切换到 文字 B，		//setInAnimation()后，A将执行inAnimation，		//setOutAnimation()后，B将执行OutAnimation        setInAnimation(mInUp);        setOutAnimation(mOutUp);	}		private Rotate3dAnimation createAnim(float start, float end, boolean turnIn, boolean turnUp){        final Rotate3dAnimation rotation = new Rotate3dAnimation(start, end, turnIn, turnUp);        rotation.setDuration(800);        rotation.setFillAfter(false);        rotation.setInterpolator(new AccelerateInterpolator());        return rotation;	}	//这里返回的TextView，就是我们看到的View	@Override	public View makeView() {		// TODO Auto-generated method stub		TextView t = new TextView(mContext);		t.setGravity(Gravity.CENTER);		t.setTextSize(mHeight);		t.setMaxLines(2);		return t;	}	//定义动作，向下滚动翻页	public void previous(){		if(getInAnimation() != mInDown){			setInAnimation(mInDown);		}		if(getOutAnimation() != mOutDown){			setOutAnimation(mOutDown);		}	}	//定义动作，向上滚动翻页	public void next(){		if(getInAnimation() != mInUp){			setInAnimation(mInUp);		}		if(getOutAnimation() != mOutUp){			setOutAnimation(mOutUp);		}	}		 class Rotate3dAnimation extends Animation {		    private final float mFromDegrees;		    private final float mToDegrees;		    private float mCenterX;		    private float mCenterY;		    private final boolean mTurnIn;		    private final boolean mTurnUp;		    private Camera mCamera;		    public Rotate3dAnimation(float fromDegrees, float toDegrees, boolean turnIn, boolean turnUp) {		        mFromDegrees = fromDegrees;		        mToDegrees = toDegrees;		        mTurnIn = turnIn;		        mTurnUp = turnUp;		    }		    @Override		    public void initialize(int width, int height, int parentWidth, int parentHeight) {		        super.initialize(width, height, parentWidth, parentHeight);		        mCamera = new Camera();		        mCenterY = getHeight() / 2;		        mCenterX = getWidth() / 2;		    }		    		    @Override		    protected void applyTransformation(float interpolatedTime, Transformation t) {		        final float fromDegrees = mFromDegrees;		        float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime);		        final float centerX = mCenterX ;		        final float centerY = mCenterY ;		        final Camera camera = mCamera;		        final int derection = mTurnUp ? 1: -1;		        final Matrix matrix = t.getMatrix();		        camera.save();		        if (mTurnIn) {		            camera.translate(0.0f, derection *mCenterY * (interpolatedTime - 1.0f), 0.0f);		        } else {		            camera.translate(0.0f, derection *mCenterY * (interpolatedTime), 0.0f);		        }		        camera.rotateX(degrees);		        camera.getMatrix(matrix);		        camera.restore();		        matrix.preTranslate(-centerX, -centerY);		        matrix.postTranslate(centerX, centerY);		    }	 }}

每日一道理

风，那么轻柔，带动着小树、小草一起翩翩起舞，当一阵清风飘来，如同母亲的手轻轻抚摸自己的脸庞，我喜欢那种感觉，带有丝丝凉意，让人心旷神怡。享受生活，不一定要有山珍海味、菱罗绸缎为伴，大自然便是上帝所赐予人类最为珍贵的。

2. MainActivity.java

package com.example.animtextview;import android.os.Bundle;import android.app.Activity;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class MainActivity extends Activity implements OnClickListener {	private Button mBtnNext;	private Button mBtnPrev;	private AutoTextView mTextView02;	private static int sCount = 10;	@Override	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);		init();	}	private void init() {		// TODO Auto-generated method stub		mBtnNext = (Button) findViewById(R.id.next);		mBtnPrev = (Button) findViewById(R.id.prev);		mTextView02 = (AutoTextView) findViewById(R.id.switcher02);		mTextView02.setText("Hello world!");		mBtnPrev.setOnClickListener(this);		mBtnNext.setOnClickListener(this);	}		@Override	public void onClick(View arg0) {		// TODO Auto-generated method stub		switch (arg0.getId()) {		case R.id.next:			mTextView02.next();			sCount++;			break;		case R.id.prev:			mTextView02.previous();			sCount--;			break;		}		mTextView02.setText(sCount%2==0 ? 				sCount+"AAFirstAA" :				sCount+"BBBBBBB");		System.out.println("getH: ["+mTextView02.getHeight()+"]");			}}

3. activity_main.xml

代码中没写太多注释，不过结构还算清晰，应该不难看懂！

三小结

我认为该控件实现的难点在于动画文件的编写，即Rotate3dAnimation中applyTransformation(...)方法的实现，通过控制camara在Y方向上挪动和在X方向上的旋转，从而造成上下翻滚的视觉感，然后将该值转换到matrix上，从而改变了参数（..，Transformation t）.有兴致的朋友可以直接改写该方法，便可失掉不同动画效果的TextSwitcher.

原文地址： http://blog.csdn.net/zjc08125/article/details/8953140

转载请注明出处

四源代码

源码地址：http://pan.baidu.com/share/link?shareid=477859&uk=956460186

文章结束给大家分享下程序员的一些笑话语录：古鸽是一种搜索隐禽，在中国快绝迹了…初步的研究表明，古鸽的离去，很可能导致另一种长着熊爪，酷似古鸽，却又习性不同的猛禽类——犤毒鸟

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一 说明

二 代码部分：

1.AutoTextView.java

2. MainActivity.java

3. activity_main.xml

三 小结

四 源代码

一说明

二代码部分：

三小结

四源代码