图形与动画在Android中的实现

1、简单图形的绘制
       

        canvas.drawColor(Color.BLUE);

        Paint paint = new Paint();
        paint.setColor(Color.RED);
        canvas.drawRect(10, 10, 110, 110, paint);
        canvas.drawText("This is text", 10, 130, paint);

        RectF rf1 = new RectF(10, 130, 110, 230);
        canvas.drawArc(rf1, 0, 45, true, paint);
        canvas.drawLine(150, 10, 250, 110, paint);
        RectF rf2 = new RectF(150, 130, 250, 230);
        canvas.drawOval(rf2, paint);

2、自定义动画的播放
  Android中主要有两种动画模式，一种是tweenedanimation（渐变动画），即通过对场景的对象不断做图像变换产生动画效果；另一种是framebyframe（帧动画），即按照顺序播放事先配置好的动画帧。下面主要是渐变动画的应用。
  首先创建动画文件donghuaanim.xml:
 

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- 透明度变换 -->
    <alpha
        android:fromAlpha="0.1"
        android:toAlpha="1.0"
        android:duration="2000"/>

    <!-- 尺寸变换 -->
    <scale
        android:interpolator="@android:anim/accelerate_decelerate_interpolator"
        android:fromXScale="0.0"
        android:toXScale="1.4"
        android:fromYScale="0.0"
        android:toYScale="1.4"
        android:pivotX="50%"
        android:pivotY="50%"
        android:fillAfter="false"
        android:duration="3000"/>

    <!-- 位置变换 -->
    <translate
        android:fromXDelta="30"
        android:toXDelta="0"
        android:fromYDelta="30"
        android:toYDelta="50"
        android:duration="4000"/>

    <!-- 旋转变换 -->
    <rotate
        android:interpolator="@android:anim/accelerate_decelerate_interpolator"
        android:fromDegrees="0"
        android:toDegrees="+350"
        android:pivotX="50%"
        android:pivotY="50%"
        android:duration="5000"/>

</set>

  添加布局文件donghua_xml.xml:
 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/imageView"
        android:src="@mipmap/image"/>

</LinearLayout>

  添加DonghuaActivity.java文件:
 

package xiao.fuyan.testapp;

import android.app.Activity;
import android.os.Bundle;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;

/**
 * Created by xiao on 2017/1/10.
 */
public class DonghuaActivity extends Activity {
    Animation animation;
    ImageView imageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.donghua_xml);

        animation = AnimationUtils.loadAnimation(this, R.anim.donghuaanim);

        imageView = (ImageView) findViewById(R.id.imageView);
        imageView.startAnimation(animation);
    }
}