android - Nexus 5 和 Android L 上的 Material 设计

Question

我的应用程序在 Android L 上崩溃，但它可以在 android kitkat 上运行。布局上也没有 RippleDrawable。这是异常和布局；

XML 布局:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/page_background">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="30dp"
        android:layout_marginRight="30dp"
        android:inputType="textEmailAddress"
        android:ems="10"
        android:id="@+id/usernameET"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="100dp"
        android:hint="@string/username_hint" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="30dp"
        android:layout_marginRight="30dp"
        android:inputType="textPassword"
        android:ems="10"
        android:id="@+id/passwordET"
        android:layout_below="@+id/usernameET"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:hint="@string/password_hint" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="60dp"
        android:layout_marginRight="60dp"
        android:text="@string/login_text"
        android:id="@+id/loginBtn"
        android:background="@drawable/positive_button_selector"
        android:textColor="#fff"
        android:layout_below="@+id/passwordET"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="40dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/register_text"
        android:id="@+id/registerText"
        android:layout_below="@+id/loginBtn"
        android:layout_marginLeft="50dp"
        android:layout_marginTop="40dp"
        android:textColor="@color/accent_color"
        android:textSize="16sp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/forget_password"
        android:id="@+id/forgetText"
        android:layout_below="@+id/registerText"
        android:layout_marginLeft="50dp"
        android:layout_marginTop="20dp"
        android:textColor="@color/accent_color"
        android:textSize="16sp" />
</RelativeLayout>

可绘制的 xml 'positive_button_selector' :

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="false">
        <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
            <solid android:color="@color/accent_color" />
            <corners android:radius="4dp" />
        </shape>
    </item>
    <item android:state_pressed="true">
        <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
            <solid android:color="@color/teal_light" />
            <corners android:radius="4dp" />
        </shape>
    </item>
</selector>

异常:

> java.lang.NullPointerException: Attempt to invoke virtual method 'int android.content.res.ColorStateList.getColorForState(int[], int)' on a null object reference
            at android.graphics.drawable.RippleDrawable.activateHotspot(RippleDrawable.java:413)
            at android.graphics.drawable.RippleDrawable.setActive(RippleDrawable.java:229)
            at android.graphics.drawable.RippleDrawable.onStateChange(RippleDrawable.java:207)
            at android.graphics.drawable.Drawable.setState(Drawable.java:566)
            at android.view.View.drawableStateChanged(View.java:15576)
            at android.widget.TextView.drawableStateChanged(TextView.java:3477)
            at android.view.View.refreshDrawableState(View.java:15594)
            at android.view.View.handleFocusGainInternal(View.java:4779)
            at android.view.View.requestFocusNoSearch(View.java:7335)
            at android.view.View.requestFocus(View.java:7314)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2448)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2448)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2448)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2448)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2448)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2448)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2448)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2448)
            at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2492)
            at android.view.ViewGroup.requestFocus(ViewGroup.java:2451)
            at android.view.View.requestFocus(View.java:7281)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1898)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1044)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5749)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
            at android.view.Choreographer.doCallbacks(Choreographer.java:580)
            at android.view.Choreographer.doFrame(Choreographer.java:550)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
            at android.os.Handler.handleCallback(Handler.java:738)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5070)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)

Answer 1

此问题是由 Lollipop 的旧预览版引起的。如果您将设备更新到最新的预览版，您将不会再看到此崩溃。

评论提到崩溃发生在 2014 年 7 月发布的版本 LPV81C。截至 2014 年 10 月 27 日的最新预览版本是 LPX13D，没有此问题。