使用java代码动态设置渐变的背景图

package com.njsoft.ace.shoppingCart.adapter;

import android.annotation.SuppressLint;
import android.graphics.drawable.GradientDrawable;
import android.support.v4.content.ContextCompat;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import com.chad.library.adapter.base.BaseQuickAdapter;
import com.chad.library.adapter.base.BaseViewHolder;
import com.njsoft.ace.R;

import java.util.List;
import java.util.Random;

public class PaymentSelectAdapter extends BaseQuickAdapter<String, BaseViewHolder> {
private int selectPosition = -1;

public PaymentSelectAdapter(int layoutResId, List<String> list) {
    super(layoutResId, list);
}

/**
 * 选择
 *
 * @param selectPosition 当前位置
 */
public void setSelectPosition(int selectPosition) {
    this.selectPosition = selectPosition;
    notifyDataSetChanged();
}

/**
 * 删除某位置的数据
 */
public void deletePosition(int deletePosition) {
    getData().remove(deletePosition);
    notifyItemRemoved(deletePosition);
}

@Override
protected void convert(BaseViewHolder helper, String item) {
    ImageView imageView = helper.getView(R.id.Card_Img);
    RelativeLayout cardLayout = helper.getView(R.id.Card_Layout);
    if (selectPosition == helper.getAdapterPosition()) {
        imageView.setImageResource(R.mipmap.radiobutton);
    } else {
        imageView.setImageResource(R.mipmap.radiobutton_default);
    }
    //获取随机颜色
    int colors[] = { getColor(), getColor()};
    /**
    *渐变的方向，颜色
    **/
    GradientDrawable gd = new GradientDrawable(GradientDrawable.Orientation.LEFT_RIGHT, colors);
   //设置圆角
    gd.setCornerRadius(20);
  //设置背景
    cardLayout.setBackground(gd);
}

//获取随机颜色
private int getColor() {
Random random = new Random();
return 0xff000000 | random.nextInt(0x00ffffff);
}

}