Android中实现如win7里边屏幕保护图案中三维文字的效果。

具体实现如下:

activity_main.xml中定义一个用来显示文字的TextView:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent">

<TextView

android:id="@+id/tv_text"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:gravity="center"

android:text="无信号"

android:textSize="80dp"

android:layout_centerInParent="true"/>

</RelativeLayout>

MainActivity.java中定义主activity。

public class MainActivity extends Activity {

private TextView tv_text;

private String TAG = "MainActivity";

Rotate3dAnimation rotateAnim = null;

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

//隐藏标题栏

this.requestWindowFeature(Window.FEATURE_NO_TITLE);

//隐藏状态栏

this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

setContentView(R.layout.activity_main);

tv_text = (TextView) findViewById(R.id.tv_text);

if(null == tv_text){

Log.i("MainActivity", "textview null...");

}

startAnimation();

}

public void startAnimation() {

//用来获取textview的宽度和高度，否则宽度和高度都为0

ViewTreeObserver vto = tv_text.getViewTreeObserver();

vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

@Override

public void onGlobalLayout() {

// TODO Auto-generated method stub

tv_text.getViewTreeObserver().removeGlobalOnLayoutListener(this);

Log.i("MainActivity", "onGlobalLayout txtNumber.width = " + tv_text.getWidth());

Log.i("MainActivity", "onGlobalLayout txtNumber.height = " + tv_text.getHeight());

rotateAnim = new Rotate3dAnimation(tv_text.getWidth()/2, tv_text.getHeight()/2, Rotate3dAnimation.ROTATE_CLOCKWIZE);

if (rotateAnim != null) {

rotateAnim.setDuration(5000);

rotateAnim.setFillAfter(true);

rotateAnim.setInterpolator(new LinearInterpolator());

rotateAnim.setRepeatCount(-1);

rotateAnim.setRepeatMode(Animation.RESTART);

tv_text.startAnimation(rotateAnim);

}

}

});

}

}

//文字的翻转动画

public class Rotate3dAnimation extends Animation{

/** 逆时针旋转*/

public static final boolean ROTATE_CLOCKWIZE = true;

/**动画顺时针旋转*/

public static final boolean ROTATE_ANTICOLCKWIZE = false;

/** Z轴上最大深度*/

public static final float DEPTH_Z = 310.0f;

/** 图片翻转类型*/

private final boolean type;

/** 翻转中心*/

private final float centerX;

private final float centerY;

private Camera camera;

/** 用于监听动画进度*/

private InterpolatedTimeListener listener;

public Rotate3dAnimation(float cX, float cY, boolean type) { //三个参数分别为翻转的中心位置和翻转方向

centerX = cX;

centerY = cY;

this.type = type;

}

public void initialize(int width, int height, int parentWidth, int parentHeight) {

// 在构造函数之后、getTransformation()之前调用本方法。

super.initialize(width, height, parentWidth, parentHeight);

camera = new Camera();

}

public void setInterpolatedTimeListener(InterpolatedTimeListener listener) {

this.listener = listener;

}

//RotateAnimation.applyTransformation()第一个参数为动画的进度时间值，取值范围为[0.0f,1.0f]，

//第二个参数Transformation记录着动画某一帧中变形的原始数据。

//该方法在动画的每一帧显示过程中都会被调用。

protected void applyTransformation(float interpolatedTime, Transformation transformation) {

if (listener != null) {

listener.interpolatedTime(interpolatedTime);

}

float from = 0.0f, to = 0.0f;

if (type == ROTATE_CLOCKWIZE) {

from = 0.0f;

to = 180.0f;

} else if (type == ROTATE_ANTICOLCKWIZE) {

from = 360.0f;

to = 180.0f;

}

float degree = from + (to - from) * interpolatedTime;

boolean overHalf = (interpolatedTime > 0.5f);

if (overHalf) {

// 翻转过半的情况下，为保证数字仍为可读的文字而非镜面效果的文字，需翻转180度。

degree = degree - 180;

}

float depth = (0.5f - Math.abs(interpolatedTime - 0.5f)) * DEPTH_Z;

final android.graphics.Matrix matrix = transformation.getMatrix();

camera.save(); //保存原来的状态

camera.translate(0.0f, 0.0f, depth); //平移一段距离

camera.rotateY(degree); //设置旋转的角度

camera.getMatrix(matrix); //取得变换矩阵

camera.restore(); //操作完后，恢复到原来的状态

//确保图片的翻转过程一直处于组件的中心点位置

//preTranslate是指在setScale前,平移,postTranslate是指在setScale后平移

//以图片的中心点为旋转中心,如果不加这两句，就是以（0,0）点为旋转中心

matrix.preTranslate(-centerX, -centerY);

matrix.postTranslate(centerX, centerY);

}

/** 动画进度监听器。 */

public static interface InterpolatedTimeListener {

public void interpolatedTime(float interpolatedTime);

}

}

注：获取控件的宽度和高度，具体请参考:http://my.oschina.net/xiahuawuyu/blog/167949

文字的翻转动画的实现，具体请参考:http://blog.csdn.net/sodino/article/details/7703980