Android画图之抗锯齿paint和Canvas两种方式实例

在画图的时候,图片如果旋转或缩放之后,总是会出现那些华丽的锯齿。其实Android自带了解决方式。

方法一:给Paint加上抗锯齿标志。然后将Paint对象作为参数传给canvas的绘制方法。

paint.setAntiAlias(true);

方法二:给Canvas加上抗锯齿标志。

有些地方不能用paint的,就直接给canvas加抗锯齿,更方便。

canvas.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG|Paint.FILTER_BITMAP_FLAG)); 


eg:

import android.content.Context;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.Matrix;

import android.graphics.Paint;

import android.graphics.PaintFlagsDrawFilter;

import android.view.View;

public class MyView extends View {

private PaintFlagsDrawFilter pfd;

private Paint mPaint = new Paint();

private Matrix matrix = new Matrix();;

private Bitmap bmp;

public MyView(Context context) {

super(context);

initialize();

}

private void initialize() {

pfd = new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG|Paint.FILTER_BITMAP_FLAG);

mPaint.setAntiAlias(true);

matrix.setRotate(30);

matrix.postScale(0.5f, 0.5f);

bmp = BitmapFactory.decodeResource(getResources(), R.drawable.show);

}

@Override

public void dispatchDraw(Canvas canvas) {

canvas.translate(100, 0);

canvas.drawBitmap(bmp, matrix, null);

canvas.translate(0, 250);

canvas.drawBitmap(bmp, matrix, mPaint);

canvas.setDrawFilter(pfd);

canvas.translate(0, 250);

canvas.drawBitmap(bmp, matrix, null);

}

}

下图是效果:

可以看出,两种方式都挺有效的。

以上是 Android画图之抗锯齿paint和Canvas两种方式实例 的全部内容, 来源链接: utcz.com/z/337094.html

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