如何替换seekbar的前景背景图

Question

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<!-- 背景图 -->
<item android:id="@android:id/background"
  android:drawable="@drawable/back" />
<!-- 进和能量图 -->
<item android:id="@android:id/progress" 
      android:drawable="@drawable/fill" />
</layer-list>我在seekbar中定义了前景图和背景图。seekbar现在能按我的要求显示前景和背景。我现在的问题是如何估代码中动态的替换前景图和背景图。假如图片比较多。如果10张前景，10张背景就要做10*10个xml。这个现实中比较麻烦。

Answer 1

O了。我用的是这个代码.
  Resources res = getResources();
        
        LayerDrawable progressDrawable =    (LayerDrawable) res.getDrawable(R.drawable.seekbar_progress);
     progressDrawable.setDrawableByLayerId(android.R.id.background, res.getDrawable(R.drawable.back));
    
     ClipDrawable proDrawable = new ClipDrawable( res.getDrawable(R.drawable.fill1), Gravity.LEFT,ClipDrawable.HORIZONTAL);
     progressDrawable.setDrawableByLayerId(android.R.id.progress,proDrawable);            seekBar1.setProgressDrawable(progressDrawable);
长大见识了。

Answer 2

这样一来，按钮，文本加了xml的看来都可以用这个方法来改变了。

Answer 3

seekbar_progress.xml, 把它放在/res/drawable/ folder:
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@android:id/background">
    <nine-patch
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:src="@drawable/seekbar_background"
        android:dither="true"
     />
</item>
<item android:id="@android:id/secondaryProgress">
    <clip>
        <shape>
            <gradient
                android:startColor="#80028ac8"
                android:centerColor="#80127fb1"
                android:centerY="0.75"
                android:endColor="#a004638f"
                android:angle="270"
            />
        </shape>
    </clip>
</item>
<item
    android:id="@android:id/progress"
    android:drawable="@drawable/seekbar_progress_bg"
/>
</layer-list>
SeekBar
<SeekBar
    android:id="@+id/frequency_slider"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:max="20"
    android:progress="0"
    android:secondaryProgress="0"
    android:progressDrawable="@drawable/seekbar_progress"
    android:thumb="@drawable/seek_thumb"
 />Programmatically
// ------------ custom seekbar
LayerDrawable layer = (LayerDrawable) verticalSeekBar_1.getProgressDrawable();Drawable draw1 = (Drawable)layer.findDrawableByLayerId(android.R.id.progress);
Bitmap bitmap1 = BitmapFactory.decodeResource(getApplicationContext().getResources(), R.drawable.scroll_on);draw1 = new ClipDrawable(new BitmapDrawable(bitmap1), Gravity.AXIS_PULL_BEFORE, ClipDrawable.HORIZONTAL);layer.setDrawableByLayerId(android.R.id.progress, draw1);Drawable draw2 = (Drawable) layer.findDrawableByLayerId(android.R.id.background);Bitmap bitmap2 = BitmapFactory.decodeResource(getApplicationContext().getResources(), R.drawable.scroll_off);draw2 = new BitmapDrawable(bitmap2);
layer.setDrawableByLayerId(android.R.id.background, draw2);你也可以参考：http://www.mokasocial.com/2011/02/create-a-custom-styled-ui-slider-seekbar-in-android/