Android开发TextvView实现镂空字体效果示例代码

Android镂空字体的实现效果图，感兴趣的朋友可以参考实现代码。

效果图：

记录一下...

自定义TextView

public class HollowTextView extends AppCompatTextView {
private Paint mTextPaint, mBackgroundPaint;
private Bitmap mBackgroundBitmap,mTextBitmap;
private Canvas mBackgroundCanvas,mTextCanvas;
private RectF mBackgroundRect;
private int mBackgroundColor;
private float mCornerRadius;

public HollowTextView(Context context) {
 this(context,null);
}

public HollowTextView(Context context, AttributeSet attrs) {
 super(context, attrs);
 initAttrs(attrs,0);
 initPaint();
}

public HollowTextView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 initAttrs(attrs,defStyleAttr);
 initPaint();
}

private void initAttrs(AttributeSet attrs,int defStyleAttr){
 if(attrs == null){
  return;
 }
 TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.HollowTextView, defStyleAttr, 0);
 mBackgroundColor = typedArray.getColor(R.styleable.HollowTextView_hollowTextView_background_color, Color.TRANSPARENT);
 mCornerRadius = typedArray.getDimension(R.styleable.HollowTextView_hollowTextView_corner_radius,0);
 typedArray.recycle();
}

/***
 * 初始化画笔属性
 */
private void initPaint() {
 //画文字的paint
 mTextPaint = new Paint();
 //这是镂空的关键
 mTextPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
 mTextPaint.setAntiAlias(true);
 mBackgroundPaint = new Paint();
 mBackgroundPaint.setColor(mBackgroundColor);
 mBackgroundPaint.setAntiAlias(true);

}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
 super.onSizeChanged(w, h, oldw, oldh);
 mBackgroundBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_4444);
 mBackgroundCanvas = new Canvas(mBackgroundBitmap);
 mTextBitmap = Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_4444);
 mTextCanvas = new Canvas(mTextBitmap);
 mBackgroundRect = new RectF(0,0,getWidth(),getHeight());
}

@Override
protected void onDraw(Canvas canvas) {
 //这里给super传入的是mTextCanvas，把一些基本属性都支持进去
 super.onDraw(mTextCanvas);
 drawBackground(mBackgroundCanvas);
 int sc;
 if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ){
  sc = canvas.saveLayer(0,0,getMeasuredWidth(),getMeasuredHeight(),null);
 }else {
  sc = canvas.saveLayer(0,0,getMeasuredWidth(),getMeasuredHeight(),null,Canvas.ALL_SAVE_FLAG);
 }
 canvas.drawBitmap(mBackgroundBitmap,0,0,null);
 canvas.drawBitmap(mTextBitmap, 0, 0, mTextPaint);
 canvas.restoreToCount(sc);
}

private void drawBackground(Canvas canvas){
 if(mCornerRadius > 0){
  canvas.drawRoundRect(mBackgroundRect,mCornerRadius,mCornerRadius, mBackgroundPaint);
 }else {
  canvas.drawColor(mBackgroundColor);
 }
}

attr.xml文件

<declare-styleable name="HollowTextView">
  <attr name="hollowTextView_background_color" format="color|reference"/>
  <attr name="hollowTextView_corner_radius" format="dimension|reference"/>
</declare-styleable>

xml中使用

<com.cn.util.HollowTextView
  android:id="@+id/hollowtext"
  android:layout_width="60dp"
  android:layout_height="50dp"
  android:gravity="center"
  android:text="99+"
  android:textSize="30sp"
  android:textStyle="bold"
  app:hollowTextView_background_color="@color/white"
  app:hollowTextView_corner_radius="5dp"
  android:layout_centerInParent="true"/>

来源：https://blog.csdn.net/congcongguniang/article/details/109330727