導(dǎo)讀

有時(shí)候腿准，我們需求上需要實(shí)現(xiàn)圓角圖片的展示肠槽。有很多種處理思路饰抒。但所有思路無非就是把Bitmap修飾成圓角或者圓形。然后顯示出來脑漫。
BitmapShader就幫我們快速的處理了髓抑。
接下來介紹的這種方式，充分體現(xiàn)了Drawable First的思想窿撬。

Drawable First

自定義Drawable，相比View來說叙凡，Drawable屬于輕量級的劈伴、使用也很簡單。以后自定義實(shí)現(xiàn)一個(gè)效果的時(shí)候握爷，可以改變View first的思想跛璧，嘗試下Drawable first掌猛。

先上效果圖

image.png

image.png

1.圓角

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作為參數(shù)傳給CircleImageDrawable趋厉，就好了！

2.圓形

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));

源碼參考我的github地址

參考文章

http://blog.csdn.net/lmj623565791/article/details/43752383