手把手教你用Android自訂餅狀圖_Android

照例先上效果圖

通過該例子，你能學到什麼：

     對Paint 深入理解，畫繪製餅圖，矩形，文字等

     加深對canvas的API的掌握，對自訂View掌握

下面我們分七步來完成一個簡單的餅形圖繪製過程。

1. 重新View的構造方法

public PieView(Context context) { this(context, null); } public PieView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public PieView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { mPieColorList = new ArrayList<>(); mPieValue = new ArrayList<>(); mStringList = new ArrayList<>(); mPaint = new Paint(); mMaxString = ""; mPaint.setColor(Color.BLACK); mPaint.setStrokeWidth(10);//畫筆寬度 mPaint.setAntiAlias(true);//消除鋸齒 }

2.繪製圖形

/** * 繪製餅圖 * * @param canvas * @param amount */ private void drawPie(Canvas canvas, int amount) { mPaint.setColor(mCurrentColor); mPaint.setStyle(Paint.Style.FILL); int angle = (int) (360f * amount / mMaxValue); Log.d("angle", "drawPie: " + angle); canvas.drawArc(oval, mStartAngle, angle, true, mPaint); mStartAngle += angle; } /** * 繪製矩形 * * @param canvas */ private void drawRect(Canvas canvas) { if (mCurrentIndex == 0) {  rect = new RectF(mRectMarginLeft, mPadding, mRectMarginLeft + RECT_WIDTH, mPadding + RECT_WIDTH);  canvas.drawRect(rect, mPaint); } else {  rect = new RectF(mRectMarginLeft, (mCurrentIndex) * TEXT_VERTICAL_PADDING + mPadding, mRectMarginLeft + RECT_WIDTH, (mCurrentIndex) * TEXT_VERTICAL_PADDING + mPadding + RECT_WIDTH);  canvas.drawRect(rect, mPaint); } } /** * 繪畫文字 * * @param canvas * @param text */ private void drawText(Canvas canvas, String text) { mPaint.setColor(TEXT_COLOR); if (mCurrentIndex == 0) {  canvas.drawText(text, mTextMarginLeft, mPadding + TEXT_SIZE * 0.8f - 5, mPaint); } else {  canvas.drawText(text, mTextMarginLeft, (mCurrentIndex) * TEXT_VERTICAL_PADDING + mPadding + TEXT_SIZE * 0.8f - 5, mPaint); } }

3.Pie 實體類

public class Pie { public int PieColor; public int PieValue; public String PieString; public Pie(int pieValue, String pieString, int pieColor) { this.PieValue = pieValue; this.PieString = pieString; this.PieColor = pieColor; }}

4.xml引用

 <aikaifa.canvas.widget.PieView android:layout_width="match_parent" android:layout_height="200dp" android:id="@+id/PieView" />

5.填充資料

public class MainActivity extends Activity { private ArrayList<Pie> pieArrayList = new ArrayList<>(); private String[] arr = {"C#", "C", "C++", "JAVA", "JavaScript", "Object-C"}; private int[] pre = {20, 30, 10, 10, 10, 20}; private PieView pieView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); pieView = (PieView) findViewById(R.id.PieView); int[] pieColor = {getResources().getColor(R.color.blue), getResources().getColor(R.color.red), getResources().getColor(R.color.gray_dark),  getResources().getColor(R.color.dark), getResources().getColor(R.color.colorPrimary), getResources().getColor(R.color.black_alpha_light)}; for (int i = 0; i < arr.length; i++) {  Pie pie = new Pie(pre[i], arr[i], pieColor[i]);  pieArrayList.add(pie); } pieView.SetPie(pieArrayList); }}

6.完整的PieView

public class PieView extends View { private Paint mPaint; //餅圖和矩形的距離 private final int PIE_RECT_PADDING = getResources().getDimensionPixelSize(R.dimen.pie_rect_padding); //矩形的寬度 private final int RECT_WIDTH = getResources().getDimensionPixelSize(R.dimen.rect_width); //矩形和文字的距離 private final int RECT_TEXT_PADDING = getResources().getDimensionPixelSize(R.dimen.rect_text_padding); //文字的大小 private final int TEXT_SIZE = getResources().getDimensionPixelSize(R.dimen.text_size); //文字的垂直距離 private final int TEXT_VERTICAL_PADDING = getResources().getDimensionPixelSize(R.dimen.text_vertical_padding); //得到文字顏色 private final int TEXT_COLOR = getResources().getColor(R.color.gray_dark); //文字和控制項頂部的距離 private float mPadding; //餅圖的半徑 private int mPieRadios; //所有數值的總和 private int mMaxValue; //餅圖開始的角度 private int mStartAngle; //文字的寬度 private int mTextWidth; //控制項半高 private int mControlHalfHeight; //當前索引 private int mCurrentIndex; //左邊距 private int mRectMarginLeft; private int mTextMarginLeft; //使用中色彩 private int mCurrentColor; //圓的範圍 private RectF oval; //最長的字串 private String mMaxString; private List<Integer> mPieColorList; private List<Integer> mPieValue; private List<String> mStringList; private ArrayList<Pie> mPieArrayList; private RectF rect; public PieView(Context context) { this(context, null); } public PieView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public PieView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { mPieColorList = new ArrayList<>(); mPieValue = new ArrayList<>(); mStringList = new ArrayList<>(); mPaint = new Paint(); mMaxString = ""; mPaint.setColor(Color.BLACK); mPaint.setStrokeWidth(10);//畫筆寬度 mPaint.setAntiAlias(true);//消除鋸齒 } @Override protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) { super.onSizeChanged(width, height, oldWidth, oldHeight); mTextWidth = (int) mPaint.measureText(mMaxString); mControlHalfHeight = height / 2; //餅圖半徑 mPieRadios = mControlHalfHeight - 5; //控制項內容寬度 int contentWidth = mPieRadios * 2 + PIE_RECT_PADDING + RECT_WIDTH + RECT_TEXT_PADDING + mTextWidth; //內容的左邊距 int contentMarginLeft = (width - contentWidth) / 2; //矩形的左邊距 mRectMarginLeft = contentMarginLeft + mPieRadios * 2 + PIE_RECT_PADDING; //文字的左邊距 mTextMarginLeft = mRectMarginLeft + RECT_WIDTH + RECT_TEXT_PADDING; //文字和控制項頂部的距離 mPadding = height / mPieArrayList.size() * 0.8f; oval = new RectF(contentMarginLeft, mControlHalfHeight - mPieRadios,  contentMarginLeft + mPieRadios * 2, mControlHalfHeight + mPieRadios); } /** * @param pieArrayList */ public void SetPie(ArrayList<Pie> pieArrayList) { mPieArrayList = pieArrayList; for (Pie mPie : mPieArrayList) {  mPieColorList.add(mPie.PieColor);  mPieValue.add(mPie.PieValue);  mStringList.add(mPie.PieString);  if (mMaxString.length() > mPie.PieString.length())  mMaxString = mPie.PieString; } //使用postInvalidate可以直接在主線程中更新介面 postInvalidate(); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); mStartAngle = -90; mCurrentIndex = 0; mMaxValue = 100; mPaint.setStyle(Paint.Style.FILL); for (int i = 0; i < mPieValue.size(); i++) {  mCurrentColor = mPieColorList.get(mCurrentIndex);  Log.i("mCurrentColor", "onDraw: " + mCurrentColor);  drawPie(canvas, mPieValue.get(mCurrentIndex));  drawRect(canvas);  drawText(canvas, mStringList.get(mCurrentIndex));  mCurrentIndex++; } } /** * 繪製餅圖 * * @param canvas * @param amount */ private void drawPie(Canvas canvas, int amount) { mPaint.setColor(mCurrentColor); mPaint.setStyle(Paint.Style.FILL); int angle = (int) (360f * amount / mMaxValue); Log.d("angle", "drawPie: " + angle); canvas.drawArc(oval, mStartAngle, angle, true, mPaint); mStartAngle += angle; } /** * 繪製矩形 * * @param canvas */ private void drawRect(Canvas canvas) { if (mCurrentIndex == 0) {  rect = new RectF(mRectMarginLeft, mPadding, mRectMarginLeft + RECT_WIDTH, mPadding + RECT_WIDTH);  canvas.drawRect(rect, mPaint); } else {  rect = new RectF(mRectMarginLeft, (mCurrentIndex) * TEXT_VERTICAL_PADDING + mPadding, mRectMarginLeft + RECT_WIDTH, (mCurrentIndex) * TEXT_VERTICAL_PADDING + mPadding + RECT_WIDTH);  canvas.drawRect(rect, mPaint); } } /** * 繪畫文字 * * @param canvas * @param text */ private void drawText(Canvas canvas, String text) { mPaint.setColor(TEXT_COLOR); if (mCurrentIndex == 0) {  canvas.drawText(text, mTextMarginLeft, mPadding + TEXT_SIZE * 0.8f - 5, mPaint); } else {  canvas.drawText(text, mTextMarginLeft, (mCurrentIndex) * TEXT_VERTICAL_PADDING + mPadding + TEXT_SIZE * 0.8f - 5, mPaint); } } @Override public boolean onTouchEvent(MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_DOWN) {  float x = event.getX();  float y = event.getY();  Log.e("",x+"-----------"); } return true; }}

7.其他檔案

colors.xml

  <color name="dark">#0097a7</color>  <color name="grey">#e0e0e0</color>  <color name="gray_dark">#666666</color>  <color name="black_alpha_light">#3c3f41</color>  <color name="black_light">#383838</color>  <color name="blue">#03a9f4</color>  <color name="red">#ff4081</color>

dimens.xml

  <dimen name="fab_margin">16dp</dimen>  <dimen name="pie_rect_padding">30dp</dimen>  <dimen name="rect_text_padding">6dp</dimen>  <dimen name="rect_width">15dp</dimen>  <dimen name="text_size">18sp</dimen>  <dimen name="text_vertical_padding">25dp</dimen>

總結

好了，這樣一個簡單的餅形圖繪製就算完成了。希望這篇文章的內容對各位Android開發人員們能有所協助，如果有疑問大家可以留言交流。