导读
有时候,我们需求上需要实现圆角图片的展示。有很多种处理思路。但所有思路无非就是把Bitmap修饰成圆角或者圆形。然后显示出来。
BitmapShader就帮我们快速的处理了。
接下来介绍的这种方式,充分体现了Drawable First的思想。
Drawable First
自定义Drawable,相比View来说,Drawable属于轻量级的、使用也很简单。以后自定义实现一个效果的时候,可以改变View first的思想,尝试下Drawable first。
先上效果图
image.png image.png1.圆角
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.Drawable;
public class CircleImageDrawable extends Drawable
{
private Paint mPaint;
private int mWidth;
private Bitmap mBitmap ;
public CircleImageDrawable(Bitmap bitmap)
{
mBitmap = bitmap ;
BitmapShader bitmapShader = new BitmapShader(bitmap, TileMode.CLAMP,
TileMode.CLAMP);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setShader(bitmapShader);
mWidth = Math.min(mBitmap.getWidth(), mBitmap.getHeight());
}
@Override
public void draw(Canvas canvas)
{
canvas.drawCircle(mWidth / 2, mWidth / 2, mWidth / 2, mPaint);
}
@Override
public int getIntrinsicWidth()
{
return mWidth;
}
@Override
public int getIntrinsicHeight()
{
return mWidth;
}
@Override
public void setAlpha(int alpha)
{
mPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(ColorFilter cf)
{
mPaint.setColorFilter(cf);
}
@Override
public int getOpacity()
{
return PixelFormat.TRANSLUCENT;
}
}
使用方法:
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.mv);
ImageView iv = (ImageView) findViewById(R.id.id_one);
iv.setImageDrawable(new CircleImageDrawable(bitmap));
iv = (ImageView) findViewById(R.id.id_two);
iv.setImageDrawable(new CircleImageDrawable(bitmap))
把Bitmap作为参数传给CircleImageDrawable,就好了!
2.圆形
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.RectF;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.Drawable;
public class RoundImageDrawable extends Drawable
{
private Paint mPaint;
private Bitmap mBitmap;
private RectF rectF;
public RoundImageDrawable(Bitmap bitmap)
{
mBitmap = bitmap;
BitmapShader bitmapShader = new BitmapShader(bitmap, TileMode.CLAMP,
TileMode.CLAMP);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setShader(bitmapShader);
}
@Override
public void setBounds(int left, int top, int right, int bottom)
{
super.setBounds(left, top, right, bottom);
rectF = new RectF(left, top, right, bottom);
}
@Override
public void draw(Canvas canvas)
{
canvas.drawRoundRect(rectF, 30, 30, mPaint);
}
@Override
public int getIntrinsicWidth()
{
return mBitmap.getWidth();
}
@Override
public int getIntrinsicHeight()
{
return mBitmap.getHeight();
}
@Override
public void setAlpha(int alpha)
{
mPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(ColorFilter cf)
{
mPaint.setColorFilter(cf);
}
@Override
public int getOpacity()
{
return PixelFormat.TRANSLUCENT;
}
}
使用方法:
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.mv);
ImageView iv = (ImageView) findViewById(R.id.id_one);
iv.setImageDrawable(new RoundImageDrawable(bitmap));
iv = (ImageView) findViewById(R.id.id_two);
iv.setImageDrawable(new RoundImageDrawable(bitmap));
源码参考我的github地址
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