如何通过xml向android中的按钮添加渐变？

Question

我无法弄清楚为什么这段代码不起作用.有人可以帮忙吗？我试图让按钮使用名为'greenstart'和'greenend'的自定义颜色.颜色已在res/value/string.xml文件中创建.我已经查看了类似的问题,但要么他们没有得到答复,不清楚,要么解决方案不起作用.提前致谢.

XML文件示例:

<Button
   android:id="@+id/mycollection"
   android:layout_width="match_parent"
   android:layout_height="fill_parent"
   android:layout_weight="1" >

   <Gradient
      android:angle="270"
      android:endColor="@color/greenstart"
      android:startColor="@color/greenend" >
   </Gradient>
</Button>

错误日志:

08-28 21:47:20.574: E/AndroidRuntime(761): FATAL EXCEPTION: main
08-28 21:47:20.574: E/AndroidRuntime(761): java.lang.RuntimeException: Unable to start activity ComponentInfo{My.Taste.App/My.Taste.App.MyTasteActivity}: android.view.InflateException: Binary XML file line #50: Error inflating class Gradient
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.ActivityThread.access$600(ActivityThread.java:123)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.os.Looper.loop(Looper.java:137)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.ActivityThread.main(ActivityThread.java:4424)
08-28 21:47:20.574: E/AndroidRuntime(761):  at java.lang.reflect.Method.invokeNative(Native Method)
08-28 21:47:20.574: E/AndroidRuntime(761):  at java.lang.reflect.Method.invoke(Method.java:511)
08-28 21:47:20.574: E/AndroidRuntime(761):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
08-28 21:47:20.574: E/AndroidRuntime(761):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
08-28 21:47:20.574: E/AndroidRuntime(761):  at dalvik.system.NativeStart.main(Native Method)
08-28 21:47:20.574: E/AndroidRuntime(761): Caused by: android.view.InflateException: Binary XML file line #50: Error inflating class Gradient
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:691)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:739)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:742)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:742)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
08-28 21:47:20.574: E/AndroidRuntime(761):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:251)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.Activity.setContentView(Activity.java:1835)
08-28 21:47:20.574: E/AndroidRuntime(761):  at My.Taste.App.MyTasteActivity.onCreate(MyTasteActivity.java:34)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.Activity.performCreate(Activity.java:4465)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
08-28 21:47:20.574: E/AndroidRuntime(761):  ... 11 more
08-28 21:47:20.574: E/AndroidRuntime(761): Caused by: java.lang.ClassNotFoundException: android.view.Gradient
08-28 21:47:20.574: E/AndroidRuntime(761):  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
08-28 21:47:20.574: E/AndroidRuntime(761):  at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
08-28 21:47:20.574: E/AndroidRuntime(761):  at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.createView(LayoutInflater.java:552)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.onCreateView(LayoutInflater.java:636)
08-28 21:47:20.574: E/AndroidRuntime(761):  at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.onCreateView(LayoutInflater.java:653)
08-28 21:47:20.574: E/AndroidRuntime(761):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:678)
08-28 21:47:20.574: E/AndroidRuntime(761):  ... 23 more

Answer 1

创建一个新的xml文件并将其放入drawable中,然后将其添加到按钮作为背景

gradient.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
    <!--  Gradient Bg for listrow -->
   <gradient
      android:startColor="#f1f1f2"
      android:centerColor="#e7e7e8"
      android:endColor="#cfcfcf"
      android:angle="270" />
</shape>

layout.xml

 <Button
    android:id="@+id/Button01"
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:layout_weight="1"
    android:background="@drawable/gradient"
    android:text="Übernehmen" >

Answer 2

试试这个 :

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" >
        <shape>
            <solid
                android:color="#70c656" />
            <stroke
                android:width="1dp"
                android:color="#53933f" />
            <corners
                android:radius="3dp" />
            <padding
                android:left="10dp"
                android:top="10dp"
                android:right="10dp"
                android:bottom="10dp" />
        </shape>
    </item>
    <item>
        <shape>
            <gradient
                android:startColor="#70c656"
                android:endColor="#53933f"
                android:angle="270" />
            <stroke
                android:width="1dp"
                android:color="#53933f" />
            <corners
                android:radius="4dp" />
            <padding
                android:left="10dp"
                android:top="10dp"
                android:right="10dp"
                android:bottom="10dp" />
        </shape>
    </item>
</selector>

Answer 3

因此，这里我们使用渐变。如上所述，@ Dusean Singh说。如果使用角度270，则渐变将从上到下开始：顶部->中心->底部

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <gradient
        android:startColor="#FF0000"
        android:centerColor="#00FF00"
        android:endColor="#0000FF"
        android:angle="270" />
</shape>

如果使用角度360，则渐变将从左到右开始：左->中心->右

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <!--  Gradient Bg for listrow -->
    <gradient
        android:startColor="#FF0000"
        android:centerColor="#00FF00"
        android:endColor="#0000FF"
        android:angle="360" />
</shape>

在这里，我们去影响。以及如何在按钮上应用相同

<LinearLayout
    android:id="@+id/design_bottom_sheet"
    android:layout_alignParentBottom="true"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:weightSum="2">
    <Button
        android:drawableLeft="@drawable/ic_grid"
        android:layout_width="match_parent"
        android:text="Find"
        android:background="@drawable/gradient_button"
        android:textColor="@color/white"
        android:textAllCaps="false"
        android:layout_height="wrap_content"
        android:layout_weight="1" />
    <Button
        android:drawableLeft="@drawable/ic_card"
        android:layout_width="match_parent"
        android:textColor="@color/white"
        android:text="Match"
        android:background="@drawable/gradient_button"
        android:textAllCaps="false"
        android:layout_height="wrap_content"
        android:layout_weight="1" />
</LinearLayout>