本文详述了android抽奖程序的实现方法，程序为一个抽奖大转盘代码，里面定义了很多图形方法和动画。
实现主要功能的SlyderView.java源代码如下：
import android.app.Activity;
import android.content.Context;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.EmbossMaskFilter;
import android.graphics.MaskFilter;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Paint.Style;
import android.graphics.PorterDuff.Mode;
import android.graphics.Path;
import android.graphics.RadialGradient;
import android.graphics.RectF;
import android.graphics.Shader.TileMode;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
public class SlyderView extends View{
public SlyderView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
public SlyderView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public SlyderView(Context context) {
super(context);
init(context);
}
/**
* 屏幕宽度
*/
private int screenW;
/**
* 屏幕的高度
*/
private int screenH;
/**
* 分割的度数
*/
private int [] drgrees = {20,50,40,90,70,40,50};
/***
* 分割的文字
*/
private String [] strs = {"level1","level2","level3","level4","level5","level6","level7"};
/**
* 分割的颜色
*/
private int [] colos = new int[] { 0xfed9c960, 0xfe57c8c8, 0xfe9fe558, 0xfef6b000, 0xfef46212, 0xfecf2911, 0xfe9d3011 };
/**
* 画笔
*/
private Paint paint;
/**
* 文字的大小
*/
private float textSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 15, getResources().getDisplayMetrics());
/**
* 文字的颜色
*/
private int textcolor = Color.WHITE;
/**
* 园的半径
*/
private float radius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 100, getResources().getDisplayMetrics());
/**
* 画文字的距离
*/
private float textdis = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 80, getResources().getDisplayMetrics());
/**
* 画箭头的大小
*/
private float roketSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 10, getResources().getDisplayMetrics());
private float initDegress = 0;
/**
* 圆心
*/
private float centerX;
/**
* 圆心
*/
private float centerY;
/**
* 立体边缘
*/
private MaskFilter filter = new EmbossMaskFilter(new float[] { 1, 1, 1 },0.4f, 6, 3.5f);
private MaskFilter outerFilter = new BlurMaskFilter(10, BlurMaskFilter.Blur.OUTER);
private MaskFilter innerFilter = new BlurMaskFilter(10, BlurMaskFilter.Blur.INNER);
@SuppressWarnings("deprecation")
private void init(Context context){
paint = new Paint();
paint.setAntiAlias(true);
paint.setStyle(Style.FILL);
paint.setColor(Color.WHITE);
screenW = ((Activity)context).getWindowManager().getDefaultDisplay().getWidth();
screenH = ((Activity)context).getWindowManager().getDefaultDisplay().getHeight();
int[] colores = new int[3];
colores[0] = Color.rgb(0xfF, 0x99, 0x00);
colores[1] = Color.rgb(0xff, 0xff, 0x00);
colores[2] = Color.rgb(0xff, 0x99, 0x00);
float[] positions = new float[3];
positions[0] = 0.0f;
positions[1] = 0.5f;
positions[2] = 1.0f;
gradient = new RadialGradient(centerX, centerY, radius/5, colores, positions, TileMode.CLAMP);
}
/**
* 绘制三角箭头
*/
private Path path = new Path();
/**
* 绘制矩形框
*/
private RectF oval;
/**
* 外圆内阴影矩阵
*/
private ColorMatrixColorFilter colorFilter = new ColorMatrixColorFilter(new float[]{
1,0,0,0,0,
0,1,0,0,0,
0,0,1,0,0,
0,0,0,-1,255
});
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
centerX = screenW/2;
centerY = screenH/2;
oval = new RectF(centerX-radius,centerY-radius,centerX+radius,centerY+radius);
float start = 0;
paint.setColor(Color.rgb(0xdd, 0xdd, 0xdd));
paint.setAlpha(127);
canvas.drawCircle(centerX, centerY, radius+10, paint);
paint.setAlpha(255);
//画扇形
paint.setAntiAlias(true);
for(int i=0;i