Android 将图片的形状设置为圆形显示

首先是依赖和权限：
**implementation 'com.nostra13.universalimageloader:universal-image-loader:1.9.2’

然后是写一个类继承android.support.v7.widget.AppCompatImageView
来看一下代码：

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.support.annotation.Nullable;
import android.util.AttributeSet;

import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.assist.ImageScaleType;
import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer;

public class DispalyImageOptions extends android.support.v7.widget.AppCompatImageView {

//画笔
private Paint mPaint;
//圆形图片的半径
private int mRadius;
//图片的宿放比例
private float mScale;

public DispalyImageOptions(Context context) {
    super(context);
}

public DispalyImageOptions(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
}

public DispalyImageOptions(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    //由于是圆形，宽高应保持一致
    int size = Math.min(getMeasuredWidth(), getMeasuredHeight());
    mRadius = size / 2;
    setMeasuredDimension(size, size);
}

@SuppressLint("DrawAllocation")
@Override
protected void onDraw(Canvas canvas) {

    mPaint = new Paint();

    Drawable drawable = getDrawable();

    if (null != drawable) {
        Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();

        //初始化BitmapShader，传入bitmap对象
        BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
        //计算缩放比例
        mScale = (mRadius * 2.0f) / Math.min(bitmap.getHeight(), bitmap.getWidth());

        Matrix matrix = new Matrix();
        matrix.setScale(mScale, mScale);
        bitmapShader.setLocalMatrix(matrix);
        mPaint.setShader(bitmapShader);
        //画圆形，指定好坐标，半径，画笔
        canvas.drawCircle(mRadius, mRadius, mRadius, mPaint);
    } else {
        super.onDraw(canvas);
    }
}

}

在Xml布局的imageview一定要改成刚才你建的那个类的全路径名（我建得类是《DispalyImageOptions 》）
<com.lgy.rk08.universalimageloader.DispalyImageOptions
android:id="@+id/meFragmentImageView"
android:layout_width=“80dip”
android:layout_height=“80dip”
android:layout_gravity=“center_horizontal”
android:layout_marginTop=“10dip”
android:contentDescription=“ssssss”
android:src="@mipmap/ic_launcher" />

需要在新建个类来设置ImageLoaderConfiguration来加载图片
import android.app.Application;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;

public class Appliction extends Application {
@Override
public void onCreate() {
super.onCreate();
ImageLoaderConfiguration loaderConfiguration = new ImageLoaderConfiguration.Builder(this).build();
ImageLoader.getInstance().init(loaderConfiguration);
}
}

注意这里需要来注册

然后就是设置加载图片的路径
第一个参数是图片的路径，第一个参数是图片的id,我这里是在BaseAdapter请求网络加载的。
ImageLoader.getInstance().displayImage(list.get(position).getPic_url(), holder.imgee);