如何在RecycleViewer上更改Canvas？

Question

我有列表項中的Canvas視圖的RecycleViewer。我如何在我的RecycleViewerAdapter中更改Canvas視圖的backgrouncolor？

下面是我onBindViewHolder方法在我RecycleViewerAdapter

@Override 
public void onBindViewHolder(ViewHolder holder, int position) { 
    holder.openprice.setText(mopenPrice.get(position)); 

//How can I change backgrouncolor canvas view ???? 

} 

我ViewHolder

public ViewHolder(View itemView) { 
     super(itemView); 

     openprice = (TextView) itemView.findViewById(R.id.openprice);    
     viewx = (View) itemView.findViewById(R.id.viewx); 



    } 

itemlist.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" 
android:layout_height="80dp" 
android:background="@drawable/border_listfavorite" 
> 

<view class="com.eusecom.exforu.MyView" 
     android:layout_width="fill_parent" 
     android:layout_height="20dp" 
     android:layout_alignParentLeft="true" 
     android:id="@+id/viewx"/> 

<TextView 
    android:id="@+id/opentxt" 
    android:text="@string/opentxt" 
    android:singleLine="true" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_below="@+id/viewx" 
    /> 

<TextView 
    android:id="@+id/openprice" 
    android:singleLine="true" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_toRightOf="@+id/opentxt" 
    android:layout_below="@+id/viewx" 
    /> 


</RelativeLayout> 

MyView.java

public class MyView extends View { 
public MyView(Context cxt, AttributeSet attrs) { 
    super(cxt, attrs); 
    setMinimumHeight(100); 
    setMinimumWidth(100); 
} 

@Override 
protected void onDraw(Canvas cv) { 
    cv.drawColor(Color.WHITE); 
    Paint p = new Paint(); 
    p.setColor(Color.GREEN); 
    p.setStrokeWidth(5); 
    cv.drawLine(20, 0, 20, cv.getHeight(), p); 
} 


} 

Answer 1

使用invalidate（）方法調用onDraw方法。

@Override 
    public void onBindViewHolder(ViewHolder holder, int position) { 
    holder.viewx.setText(mopenPrice.get(position)); 

    if(condition){ 
      holder.viewx.setCustomColor(Color.GREEN); 
      holder.viewx.invalidate(); 
    } 

    } 

公共類MyView的擴展視圖{

private int color = Color.WHITE; 

public MyView(Context cxt, AttributeSet attrs) { 
    super(cxt, attrs); 
    setMinimumHeight(100); 
    setMinimumWidth(100); 
} 

@Override 
protected void onDraw(Canvas cv) { 
    cv.drawColor(color); 
    Paint p = new Paint(); 
    p.setColor(Color.GREEN); 
    p.setStrokeWidth(5); 
    cv.drawLine(20, 0, 20, cv.getHeight(), p); 
} 

public void setCustomColor(int color){ 
    this.color = color; 
} 


public ViewHolder(View itemView) { 
    private MyView viewx; 
    super(itemView); 
    openprice = (TextView) itemView.findViewById(R.id.openprice);    
    viewx = (MyView) itemView.findViewById(R.id.viewx); 

}