可以看出图中的单元格有一个半封闭的边框，这里我们可以重写gridview的dispatchDraw来实现：
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
int column = getNumColumns(); //获取列数
int row = (int) Math.ceil(getChildCount() / (float)column); //获取行数
int childCount = getChildCount();
Paint linePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
linePaint.setStyle(Paint.Style.STROKE);
linePaint.setColor(Color.WHITE);
for (int i = 0; i<childCount ; i++){
View child = getChildAt(i);
if((i+1) > column * (row - 1)){
if((i + 1) == column * row){
continue;
}else{
canvas.drawLine(child.getRight(),child.getTop(),child.getRight()
,child.getBottom(),linePaint);
}
}else if ((i+1) % column ==0){
canvas.drawLine(child.getLeft(),child.getBottom(),child.getRight()
,child.getBottom(),linePaint);
}else{
canvas.drawLine(child.getLeft(),child.getBottom(),child.getRight()
,child.getBottom(),linePaint);
canvas.drawLine(child.getRight(),child.getTop(),child.getRight()
,child.getBottom(),linePaint);
}
}
}
