android View视图的绘制

package com.pan.myview; import java.util.ArrayList; import java.util.List; import com.pan.R; import com.pan.R.string; import com.pan.info.OileUseUpInfo; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.PaintFlagsDrawFilter; import android.graphics.Path; import android.util.AttributeSet; import android.util.Log; import android.view.View; /** * 油耗信息统计图 * * @author zjpan * */ public class OileUseUpView extends View { /** * 日志标志 */ private static final String TAG = "OileUseUpView"; /** * Y轴上显示的最多的刻度 */ private static final int MAX_Y_SCALE_NUM = 10; /** * 油耗信息列表 */ private List<OileUseUpInfo> useUpList; /** * 画笔 */ private Paint paint; /** * 距上距离 */ private int toTop = 20; /** * 距下距离 */ private int toBottom = 40; /** * 距左距离 */ private int toLeft = 20; /** * 距右距离 */ private int toRight = 30; /** * 显示区域的高 */ private int showHeight; /** * 显示区域宽 */ private int showWidth; /** * X轴上每个刻度的宽 */ private int preLengthX; /** * Y轴上每个刻度的高度 */ private int preLengthY; /** * 最小油耗的floor整数 */ private int floorMinOile; /** * 是否只有一条数据 */ private boolean isOneData; /** * 最小的油耗 */ private float minOile; /** * 最大油耗 */ private float maxOile; /** * Y轴上画几个刻度 */ private int countY; /** * 最近日期的月 */ private int maxMonth; /** * 一个油耗和一格刻度的比例 */ private int oileUseUpRate = 1; /** * 最近日期的年 */ private int maxYear; /** * 最早日期的年 */ private int minYear; /** * 最早日期的月 */ private int minMonth; public OileUseUpView(Context context) { super(context); paint = new Paint(); } public OileUseUpView(Context context, AttributeSet attrs) { super(context, attrs); paint = new Paint(); } protected void onDraw(Canvas canvas) { // 如果还没有数据，不绘制 if (null == useUpList || useUpList.size()==0) { return; } showWidth = getWidth(); showHeight = getHeight(); // 画X轴 paint.setAntiAlias(true); paint.setColor(Color.WHITE); paint.setStrokeWidth(3.0f); canvas.drawLine(toLeft, showHeight - toBottom, showWidth - toRight, showHeight - toBottom, paint); paint.setTextSize(12); canvas.drawText(getResources().getString(R.string.month), showWidth - toRight + 5, showHeight - toBottom + 5, paint); // 画箭头 Path mPath = new Path(); mPath.moveTo(showWidth - toRight - 5, showHeight - toBottom - 5); mPath.lineTo(showWidth - toRight - 5, showHeight - toBottom + 5); mPath.lineTo(showWidth - toRight + 5, showHeight - toBottom); mPath.close(); canvas.drawPath(mPath, paint); // 取出最大的日期 String[] strDate = useUpList.get(useUpList.size() - 1).getDate().split( "-"); maxYear = Integer.parseInt(strDate[0]); maxMonth = Integer.parseInt(strDate[1]); // 显示最近十二个月的油耗情况，这里算出显示距离现在时间最长的日期年、月 if (maxMonth == 12) { minMonth = 1; minYear = maxYear; } else { minMonth = maxMonth + 1; minYear = maxYear - 1; } Log.d(TAG, "maxYear/MaxMonth = " + maxYear + "/" + maxMonth); Log.d(TAG, "minYear/MinMonth = " + minYear + "/" + minMonth); int tempMonth = minMonth; // 画X轴上刻度 preLengthX = (showWidth - toLeft - toRight - 5) / 12; paint.setTextSize(10f); for (int i = 0; i < 12; i++) { paint.setStrokeWidth(1.0f); canvas .drawLine(toLeft + (preLengthX * i), showHeight - toBottom, toLeft + (preLengthX * i), showHeight - toBottom - 5, paint); paint.setStrokeWidth(0.2f); paint.setAntiAlias(false); canvas.drawLine(toLeft + (preLengthX * i), showHeight - toBottom, toLeft + (preLengthX * i), toTop, paint); paint.setAntiAlias(true); tempMonth = tempMonth > 12 ? tempMonth - 12 : tempMonth; // 画X轴上的年或月 if (tempMonth == 1) { canvas.drawText(String.valueOf(maxYear), toLeft + (preLengthX * i) - 10, showHeight - toBottom + 15, paint); } else { int moveX = tempMonth > 9 ? 5 : 2; canvas.drawText(String.valueOf(tempMonth), toLeft + (preLengthX * i) - moveX, showHeight - toBottom + 15, paint); } tempMonth++; } // 画X轴下的说明 int tempPreWidth = (showWidth - toLeft - toRight - 40) / 3; paint.setColor(Color.YELLOW); paint.setStyle(Paint.Style.STROKE); paint.setStrokeWidth(1); canvas.drawCircle(toLeft + 20, showHeight - toBottom + 30, 3, paint); paint = new Paint(); paint.setAntiAlias(true); paint.setColor(Color.WHITE); paint.setTextSize(12); canvas.drawText(getResources().getString(R.string.current_use_up), toLeft + 30, showHeight - toBottom + 34, paint); canvas.drawText(getResources().getString(R.string.oile_change), toLeft + tempPreWidth + 45, showHeight - toBottom + 34, paint); canvas.drawText(getResources().getString(R.string.oile_avg), toLeft + (tempPreWidth * 2) + 55, showHeight - toBottom + 34, paint); paint.setColor(Color.RED); paint.setStrokeWidth(2.0f); canvas.drawLine(toLeft + tempPreWidth + 20, showHeight - toBottom + 30, toLeft + tempPreWidth + 40, showHeight - toBottom + 30, paint); paint.setColor(Color.GREEN); canvas.drawLine(toLeft + (tempPreWidth * 2) + 30, showHeight - toBottom + 30, toLeft + (tempPreWidth * 2) + 50, showHeight - toBottom + 30, paint); // 画Y轴 minOile = useUpList.get(0).getOilUseUp(); maxOile = useUpList.get(0).getOilUseUp(); // 取出最小和最大的油耗 for (int i = 0; i < useUpList.size(); i++) { if (useUpList.get(i).getOilUseUp() < minOile) { minOile = useUpList.get(i).getOilUseUp(); } if (useUpList.get(i).getOilUseUp() > maxOile) { maxOile = useUpList.get(i).getOilUseUp(); } } floorMinOile = (int) Math.floor(minOile); // 最高油耗与最小油耗的差值，用于计算Y轴刻度的精度 int differenceCount = (int) (Math.ceil(maxOile) - floorMinOile); oileUseUpRate = (differenceCount / MAX_Y_SCALE_NUM) + 1; // Y轴最多显示MAX_Y_SCALE_NUM个刻度（如果油耗相差太大，刻度太多看不清楚） if (differenceCount / MAX_Y_SCALE_NUM > 0) { countY = MAX_Y_SCALE_NUM; } else { countY = differenceCount; } Log.d(TAG, "countY = "+countY); if(countY==0) { isOneData = true; preLengthY = showHeight; } else { isOneData = false; preLengthY = (showHeight - toTop - toBottom) / countY; } paint = new Paint(); paint.setAntiAlias(true); paint.setColor(Color.WHITE); paint.setStrokeWidth(3.0f); canvas.drawLine(toLeft, showHeight - toBottom, toLeft, toTop, paint); Path path = new Path(); path.moveTo(toLeft - 5, toTop + 5); path.lineTo(toLeft + 5, toTop + 5); path.lineTo(toLeft, toTop - 5); path.close(); canvas.drawPath(path, paint); paint.setTextSize(12); canvas.drawText(getResources().getString(R.string.oile_use_up), toLeft - 12, toTop - 8, paint); // 画Y轴上的刻度 int tempPreY; // Y轴上刻度对应的值 int tempNum = floorMinOile; for (int i = 0; i < countY; i++) { paint.setStrokeWidth(1.0f); tempPreY = showHeight - toBottom - (preLengthY * i); canvas.drawLine(toLeft, tempPreY, toLeft + 5, tempPreY, paint); paint.setTextSize(10); paint.setStrokeWidth(0.2f); paint.setAntiAlias(