学步园

1、在drawable目录下新建XML文件progressbar_horizontal_red：

<?xml version="1.0" encoding="utf-8"?>
	<!--
		Copyright (C) 2008 The Android Open Source Project Licensed under the
		Apache License, Version 2.0 (the "License"); you may not use this file
		except in compliance with the License. You may obtain a copy of the
		License at http://www.apache.org/licenses/LICENSE-2.0 Unless required
		by applicable law or agreed to in writing, software distributed under
		the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
		CONDITIONS OF ANY KIND, either express or implied. See the License for
		the specific language governing permissions and limitations under the
		License.
	-->

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

	<item android:id="@android:id/background">
		<shape>
			<corners android:radius="5dip" />
			<gradient android:startColor="#ff333333"
				android:centerColor="#ff4a4a4a" android:centerY="0.75"
				android:endColor="#ff333333" android:angle="270" />
		</shape>
	</item>

	<item android:id="@android:id/secondaryProgress">
		<clip>
			<shape>
				<corners android:radius="5dip" />
				<gradient android:startColor="#8000AADD"
					android:centerColor="#8000AADD" android:centerY="0.75"
					android:endColor="#8000AADD" android:angle="270" />
			</shape>
		</clip>
	</item>

	<item android:id="@android:id/progress">
		<clip>
			<shape>
				<corners android:radius="5dip" />
				<gradient android:startColor="#fffa6b6b"
					android:centerColor="#ffff0000" android:centerY="0.75"
					android:endColor="#ffe80202" android:angle="270" />
			</shape>
		</clip>
	</item>

</layer-list>

2、在values目录下新建XML文件styles：

<?xml version="1.0" encoding="utf-8"?>
<resources> 
   <style name="progressbarStyle_Horizontal_Red" parent="android:Widget.ProgressBar.Horizontal">
    	<item name="android:indeterminateOnly">false</item>
    	<item name="android:progressDrawable">@drawable/progressbar_horizontal_red</item>
    	<item name="android:minHeight">12.0dp</item>
    	<item name="android:maxHeight">12.0dp</item>
    </style>
</resources>

3、布局文件代码：

<ProgressBar
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	style="@style/progressbarStyle_Horizontal_Red" />

运行起来之后可以发现水平进度条已经变成红色的了~