Android--雷達掃描動態界面

效果圖：

源碼：

package com.zihao.radar;

import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.view.WindowManager;

import com.zihao.radar.view.RadarView;

public class MainActivity extends Activity {

	private RadarView mRadarView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		// 取消狀態欄
		getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
				WindowManager.LayoutParams.FLAG_FULLSCREEN);
		setContentView(R.layout.activity_main);
		mRadarView = (RadarView) findViewById(R.id.radar_view);
		mRadarView.setSearching(true);
		mRadarView.addPoint();
		mRadarView.addPoint();
	}

}

package com.zihao.radar.view;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.util.AttributeSet;
import android.view.View;

import com.zihao.radar.R;

/**
 * @ClassName：RadarView
 * @Description：TODO<雷達掃描視圖>
 * @author：zihao
 * @date：2015年11月11日 上午12:26:11
 * @version：v1.1
 */
@SuppressLint("DrawAllocation")
public class RadarView extends View {

	private Context mContext;
	private boolean isSearching = false;// 標識是否處於掃描狀態,默認為不在掃描狀態
	private Paint mPaint;// 畫筆
	private Bitmap mScanBmp;// 執行掃描運動的圖片
	private int mOffsetArgs = 0;// 掃描運動偏移量參數
	private Bitmap mDefaultPointBmp;// 標識設備的圓點-默認
	private Bitmap mLightPointBmp;// 標識設備的圓點-高亮
	private int mPointCount = 0;// 圓點總數
	private List mPointArray = new ArrayList();// 存放偏移量的map
	private Random mRandom = new Random();
	private int mWidth, mHeight;// 寬高
	int mOutWidth;// 外圓寬度(w/4/5*2=w/10)
	int mCx, mCy;// x、y軸中心點
	int mOutsideRadius, mInsideRadius;// 外、內圓半徑

	public RadarView(Context context, AttributeSet attrs, int defStyleAttr) {
		super(context, attrs, defStyleAttr);
		// TODO Auto-generated constructor stub
		init(context);
	}

	public RadarView(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
		init(context);
	}

	public RadarView(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
		init(context);
	}

	/**
	 * TODO<提前初始化好需要使用的對象,避免在繪制過程中多次初始化>
	 * 
	 * @return void
	 */
	private void init(Context context) {
		mPaint = new Paint();
		this.mContext = context;
		this.mDefaultPointBmp = Bitmap.createBitmap(BitmapFactory
				.decodeResource(mContext.getResources(),
						R.drawable.radar_default_point_ico));
		this.mLightPointBmp = Bitmap.createBitmap(BitmapFactory.decodeResource(
				mContext.getResources(), R.drawable.radar_light_point_ico));
	}

	/**
	 * 測量視圖及其內容,以確定所測量的寬度和高度(測量獲取控件尺寸).
	 */
	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		// TODO Auto-generated method stub
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);

		// 獲取控件區域寬高
		if (mWidth == 0 || mHeight == 0) {
			final int minimumWidth = getSuggestedMinimumWidth();
			final int minimumHeight = getSuggestedMinimumHeight();
			mWidth = resolveMeasured(widthMeasureSpec, minimumWidth);
			mHeight = resolveMeasured(heightMeasureSpec, minimumHeight);
			mScanBmp = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(
					mContext.getResources(), R.drawable.radar_scan_img), mWidth
					- mOutWidth, mWidth - mOutWidth, false);

			// 獲取x/y軸中心點
			mCx = mWidth / 2;
			mCy = mHeight / 2;

			// 獲取外圓寬度
			mOutWidth = mWidth / 10;

			// 計算內、外半徑
			mOutsideRadius = mWidth / 2;// 外圓的半徑
			mInsideRadius = (mWidth - mOutWidth) / 4 / 2;// 內圓的半徑,除最外層,其它圓的半徑=層數*insideRadius
		}
	}

	/**
	 * 繪制視圖--從外部向內部繪制
	 */
	@Override
	protected void onDraw(Canvas canvas) {
		// TODO Auto-generated method stub
		super.onDraw(canvas);
		// 開始繪制最外層的圓
		mPaint.setAntiAlias(true);// 設置抗鋸齒
		mPaint.setStyle(Style.FILL);// 設置填充樣式
		mPaint.setColor(0xffB8DCFC);// 設置畫筆顏色
		// 1.開始繪制圓形
		canvas.drawCircle(mCx, mCy, mOutsideRadius, mPaint);

		// 開始繪制內4圓
		mPaint.setColor(0xff3278B4);
		canvas.drawCircle(mCx, mCy, mInsideRadius * 4, mPaint);

		// 開始繪制內3圓
		mPaint.setStyle(Style.STROKE);
		mPaint.setColor(0xff31C9F2);
		canvas.drawCircle(mCx, mCy, mInsideRadius * 3, mPaint);

		// 開始繪制內2圓
		canvas.drawCircle(mCx, mCy, mInsideRadius * 2, mPaint);

		// 開始繪制內1圓
		canvas.drawCircle(mCx, mCy, mInsideRadius * 1, mPaint);

		// 2.開始繪制對角線
		canvas.drawLine(mOutWidth / 2, mCy, mWidth - mOutWidth / 2, mCy, mPaint);// 繪制0°~180°對角線
		canvas.drawLine(mCx, mHeight - mOutWidth / 2, mCx, mOutWidth / 2,
				mPaint);// 繪制90°~270°對角線

		// 根據角度繪制對角線
		int startX, startY, endX, endY;
		double radian;

		// 繪制45°~225°對角線
		// 計算開始位置x/y坐標點
		radian = Math.toRadians((double) 45);// 將角度轉換為弧度
		startX = (int) (mCx + mInsideRadius * 4 * Math.cos(radian));// 通過圓心坐標、半徑和當前角度計算當前圓周的某點橫坐標
		startY = (int) (mCy + mInsideRadius * 4 * Math.sin(radian));// 通過圓心坐標、半徑和當前角度計算當前圓周的某點縱坐標
		// 計算結束位置x/y坐標點
		radian = Math.toRadians((double) 45 + 180);
		endX = (int) (mCx + mInsideRadius * 4 * Math.cos(radian));
		endY = (int) (mCy + mInsideRadius * 4 * Math.sin(radian));
		canvas.drawLine(startX, startY, endX, endY, mPaint);

		// 繪制135°~315°對角線
		// 計算開始位置x/y坐標點
		radian = Math.toRadians((double) 135);
		startX = (int) (mCx + mInsideRadius * 4 * Math.cos(radian));
		startY = (int) (mCy + mInsideRadius * 4 * Math.sin(radian));
		// 計算結束位置x/y坐標點
		radian = Math.toRadians((double) 135 + 180);
		endX = (int) (mCx + mInsideRadius * 4 * Math.cos(radian));
		endY = (int) (mCy + mInsideRadius * 4 * Math.sin(radian));
		canvas.drawLine(startX, startY, endX, endY, mPaint);

		// 3.繪制掃描扇形圖
		canvas.save();// 用來保存Canvas的狀態.save之後，可以調用Canvas的平移、放縮、旋轉、錯切、裁剪等操作.

		if (isSearching) {// 判斷是否處於掃描
			canvas.rotate(mOffsetArgs, mCx, mCy);// 繪制旋轉角度,參數一：角度;參數二：x中心;參數三：y中心.
			canvas.drawBitmap(mScanBmp, mCx - mScanBmp.getWidth() / 2, mCy
					- mScanBmp.getHeight() / 2, null);// 繪制Bitmap掃描圖片效果
			mOffsetArgs += 3;
		} else {
			canvas.drawBitmap(mScanBmp, mCx - mScanBmp.getWidth() / 2, mCy
					- mScanBmp.getHeight() / 2, null);
		}

		// 4.開始繪制動態點
		canvas.restore();// 用來恢復Canvas之前保存的狀態.防止save後對Canvas執行的操作對後續的繪制有影響.

		if (mPointCount > 0) {// 當圓點總數>0時,進入下一層判斷

			if (mPointCount > mPointArray.size()) {// 當圓點總數大於存儲坐標點數目時,說明有增加,需要重新生成隨機坐標點
				int mx = mInsideRadius + mRandom.nextInt(mInsideRadius * 6);
				int my = mInsideRadius + mRandom.nextInt(mInsideRadius * 6);
				mPointArray.add(mx + "/" + my);
			}

			// 開始繪制坐標點
			for (int i = 0; i < mPointArray.size(); i++) {
				String[] result = mPointArray.get(i).split("/");

				// 開始繪制動態點
				if (i < mPointArray.size() - 1)
					canvas.drawBitmap(mDefaultPointBmp,
							Integer.parseInt(result[0]),
							Integer.parseInt(result[1]), null);
				else
					canvas.drawBitmap(mLightPointBmp,
							Integer.parseInt(result[0]),
							Integer.parseInt(result[1]), null);
			}
		}

		if (isSearching)
			this.invalidate();
	}

	/**
	 * TODO<設置掃描狀態>
	 * 
	 * @return void
	 */
	public void setSearching(boolean status) {
		this.isSearching = status;
		this.invalidate();
	}

	/**
	 * TODO<新增動態點>
	 * 
	 * @return void
	 */
	public void addPoint() {
		mPointCount++;
		this.invalidate();
	}

	/**
	 * TODO<解析獲取控件寬高>
	 * 
	 * @return int
	 */
	private int resolveMeasured(int measureSpec, int desired) {
		int result = 0;
		int specSize = MeasureSpec.getSize(measureSpec);
		switch (MeasureSpec.getMode(measureSpec)) {
		case MeasureSpec.UNSPECIFIED:
			result = desired;
			break;
		case MeasureSpec.AT_MOST:
			result = Math.min(specSize, desired);
			break;
		case MeasureSpec.EXACTLY:
		default:
			result = specSize;
		}
		return result;
	}
}