自定义的ImageView与阴影 [英] Custom ImageView with drop shadow

问题描述

好吧，我一直在阅读和摸索，而我现在敲我的头撞在墙上试图找出了这一点。这是我到目前为止有：

 包com.pockdroid.sandbox;

进口android.content.Context;
进口android.graphics.Canvas;
进口android.graphics.Color;
进口android.graphics.Paint;
进口android.graphics.Rect;
进口android.widget.ImageView;

公共类ShadowImageView扩展ImageView的{

私人矩形mRect;
私人油漆mPaint;

公共ShadowImageView（上下文的背景下）
{
    超（上下文）;
    mRect =新的矩形（）;
    mPaint =新的油漆（）;
    mPaint.setAntiAlias​​（真正的）;
    mPaint.setShadowLayer（2F，1F，1F，Color.BLACK）;
}

@覆盖
保护无效的OnDraw（帆布油画）
{
    矩形R = mRect;
    涂料粉刷= mPaint;

    canvas.drawRect（R，漆）;
    super.onDraw（画布）;
}

@覆盖
保护无效onMeasure（INT W，INT高）
{
    super.onMeasure（W，H）;
    INT mH为毫瓦;
    毫瓦= getSuggestedMinimumWidth（）＆其中; getMeasuredWidth（）？ getMeasuredWidth（）：getSuggestedMinimumWidth（）;
    毫亨= getSuggestedMinimumHeight（）＆其中; getMeasuredHeight（）？ getMeasuredHeight（）：getSuggestedMinimumHeight（）;
    setMeasuredDimension（MW + 5，MH + 5）;
}
 

}

在测量的+5是有作为临时的;据我了解，我需要做一些数学来确定的阴影添加到画布的大小，对不对？

但是当我使用这样的：

 公开查看getView（INT位置，查看convertView，ViewGroup中父）{
    ShadowImageView sImageView;
    如果（convertView == NULL）{
        sImageView =新ShadowImageView（mContext）;
        GridView.LayoutParams LP =新GridView.LayoutParams（85，85）;
        sImageView.setLayoutParams（LP）;

        sImageView.setScaleType（ImageView.ScaleType.CENTER）;
        sImageView.setPadding（5,5,5,5）;
    } 其他 {
        sImageView =（ShadowImageView）convertView;
    }

    sImageView.setImageBitmap（bitmapList.get（位置））;
    返回sImageView;
}
 

在我的ImageView，我仍然得到的只是一个普通的ImageView当我运行该程序。

有什么想法？谢谢你。

编辑：所以我在IRC频道采访了RomainGuy一些，我有它的工作现在普通的矩形图像下面code。它仍然不会直接绘制阴影，以我的位图的透明的，所以我还在上。

  @覆盖
保护无效的OnDraw（帆布油画）
{
    BMP位= BitmapFactory.de codeResource（getResources（），R.drawable.omen）;
    涂料粉刷=新的油漆（）;
    paint.setAntiAlias​​（真正的）;
    paint.setShadowLayer（5.5F，6.0f，6.0f，Color.BLACK）;
    canvas.drawColor（Color.GRAY）;
    canvas.drawRect（50，50，50 + bmp.getWidth（），50 + bmp.getHeight（），漆）;
    canvas.drawBitmap（BMP，50，50，NULL）;
}
 

解决方案

好吧，我不预见这一个更多的答案，所以我结束了去了，现在只需矩形图像的解决方案。我用下面的NinePatch：



随着XML适当的填充：

 ＆LT; ImageView的
        机器人：ID =@ + ID / image_test
        机器人：背景=@可绘制/ drop_shadow
        机器人：layout_width =WRAP_CONTENT
        机器人：layout_height =WRAP_CONTENT
        机器人：以下属性来=6px
        机器人：paddingTop =递四方
        机器人：paddingRight =8像素
        机器人：paddingBottom会=9px
        机器人：SRC =@可绘制/ PIC1
        /＆GT;
 

获得了相当不错的成绩：



不理想，但它会做。

Okay, I've been reading and searching around, and am now banging my head against the wall trying to figure this out. Here's what I have so far:

package com.pockdroid.sandbox;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.widget.ImageView;

public class ShadowImageView extends ImageView {

private Rect mRect;
private Paint mPaint;

public ShadowImageView(Context context)
{
    super(context);
    mRect = new Rect();
    mPaint = new Paint();
    mPaint.setAntiAlias(true);
    mPaint.setShadowLayer(2f, 1f, 1f, Color.BLACK);
}

@Override
protected void onDraw(Canvas canvas) 
{
    Rect r = mRect;
    Paint paint = mPaint;

    canvas.drawRect(r, paint);
    super.onDraw(canvas);
}

@Override
protected void onMeasure(int w, int h)
{
    super.onMeasure(w,h);
    int mH, mW;
    mW = getSuggestedMinimumWidth() < getMeasuredWidth()? getMeasuredWidth() : getSuggestedMinimumWidth();
    mH = getSuggestedMinimumHeight() < getMeasuredHeight()? getMeasuredHeight() : getSuggestedMinimumHeight();
    setMeasuredDimension(mW + 5, mH + 5);
}

}

The "+5" in the measurements are there as temporary; From what I understand I'll need to do some math to determine the size that the drop shadow adds to the canvas, right?

But when I use this:

public View getView(int position, View convertView, ViewGroup parent) {
    ShadowImageView sImageView;
    if (convertView == null) {
        sImageView = new ShadowImageView(mContext);
        GridView.LayoutParams lp = new GridView.LayoutParams(85, 85);
        sImageView.setLayoutParams(lp);

        sImageView.setScaleType(ImageView.ScaleType.CENTER);
        sImageView.setPadding(5,5,5,5);
    } else {
        sImageView = (ShadowImageView) convertView;
    }

    sImageView.setImageBitmap(bitmapList.get(position));
    return sImageView;
}

in my ImageView, I still get just a normal ImageView when I run the program.

Any thoughts? Thanks.

EDIT: So I spoke with RomainGuy some in the IRC channel, and I have it working now for plain rectangular images with the below code. It still won't draw the shadow directly to my bitmap's transparency though, so I'm still working on that.

@Override
protected void onDraw(Canvas canvas) 
{
    Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.omen);
    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShadowLayer(5.5f, 6.0f, 6.0f, Color.BLACK);
    canvas.drawColor(Color.GRAY);
    canvas.drawRect(50, 50, 50 + bmp.getWidth(), 50 + bmp.getHeight(), paint);
    canvas.drawBitmap(bmp, 50, 50, null);       
}

解决方案

Okay, I don't foresee any more answers on this one, so what I ended up going with for now is just a solution for rectangular images. I've used the following NinePatch:



along with the appropriate padding in XML:

<ImageView
        android:id="@+id/image_test"
        android:background="@drawable/drop_shadow"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingLeft="6px"
        android:paddingTop="4px"
        android:paddingRight="8px"
        android:paddingBottom="9px"
        android:src="@drawable/pic1"
        />

to get a fairly good result:



Not ideal, but it'll do.

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