public class AutoWrapTextView extends View {

}

public AutoWrapTextView(Context context, AttributeSet attrs) {
  super(context, attrs);

  init(context, attrs);
}

private void init(Context context, AttributeSet attrs) {
  initStyle(context, attrs);
  initPaint();
}

 private void initStyle(Context context, AttributeSet attrs) {
  TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.AutoWrapTextViewStyle);
  mPaddingLeft = typedArray.getDimensionPixelSize(R.styleable.AutoWrapTextViewStyle_paddingLeft, 0);
  mPaddingRight = typedArray.getDimensionPixelSize(R.styleable.AutoWrapTextViewStyle_paddingRight, 0);
  mPaddingTop = typedArray.getDimensionPixelSize(R.styleable.AutoWrapTextViewStyle_paddingTop, 0);
  mPaddingBottom = typedArray.getDimensionPixelSize(R.styleable.AutoWrapTextViewStyle_paddingBottom, 0);

  mTextColor = typedArray.getColor(R.styleable.AutoWrapTextViewStyle_textColor, Color.BLACK);
  mTextSize = typedArray.getDimensionPixelSize(R.styleable.AutoWrapTextViewStyle_textSize, 50);
  mLineSpacingExtra = typedArray.getInteger(R.styleable.AutoWrapTextViewStyle_lineSpacingExtra, 7);

  typedArray.recycle();
 }

 private void initPaint() {
  mTextPaint = new TextPaint();
  mTextPaint.setAntiAlias(true);
  mTextPaint.setTextSize(mTextSize);
  mTextPaint.setColor(mTextColor);
  mTextPaint.setTextAlign(Paint.Align.LEFT);
 }

 public void setText(String text) {
  if (TextUtils.isEmpty(text)) return;

  //把文本转换成Char数组
  mTextCharArray = text.toCharArray();
  requestLayout();
 }

 private void splitText(int heightMode) {
  if (mTextCharArray == null) return;

  mSplitTextList = new ArrayList<>();
  mSingleTextWidth = getMeasuredWidth() - mPaddingLeft - mPaddingRight;
  int currentSingleTextWidth = 0;
  StringBuffer lineStringBuffer = new StringBuffer();
  for (int i = 0, length = mTextCharArray.length; i < length; i++) {
   char textChar = mTextCharArray[i];
   currentSingleTextWidth += getSingleCharWidth(textChar);
   if (currentSingleTextWidth > mSingleTextWidth) {
    mSplitTextList.add(lineStringBuffer.toString());
    lineStringBuffer = new StringBuffer();
    currentSingleTextWidth = 0;
    i--;
   } else {
    lineStringBuffer.append(textChar);
    if (i == length - 1) mSplitTextList.add(lineStringBuffer.toString());
   }
  }

  int textHeight = 0;
  mSplitTextRectArray = new Rect[mSplitTextList.size()];
  for (int m = 0, length = mSplitTextList.size(); m < length; m++) {
   String lineText = mSplitTextList.get(m);
   Rect lineTextRect = new Rect();
   mTextPaint.getTextBounds(lineText, 0, lineText.length(), lineTextRect);
   if (heightMode == MeasureSpec.AT_MOST) {
    textHeight += (lineTextRect.height() + mLineSpacingExtra);
    if (m == length - 1) {
     textHeight = textHeight + mPaddingBottom + mPaddingTop;
    }
   } else {
    if (textHeight == 0)
     textHeight = getMeasuredHeight();
   }
   mSplitTextRectArray[m] = lineTextRect;
  }

  setMeasuredDimension(getMeasuredWidth(), textHeight);
 }

 public void drawText(Canvas canvas) {
  if (mSplitTextList == null || mSplitTextList.size() == 0) return;

  int marginTop = getTopTextMarginTop();
  for (int m = 0, length = mSplitTextList.size(); m < length; m++) {
   String lineText = mSplitTextList.get(m);
   canvas.drawText(lineText, mPaddingLeft, marginTop, mTextPaint);
   marginTop += (mSplitTextRectArray[m].height() + mLineSpacingExtra);
  }
 }