Question

我使用的是第三方库，有一种使用DrawableCompat.setTintMode(drawable, PorterDuff.Mode.SRC_IN);的方法。当我在Android 5.0 +中测试我的应用程序时，没有问题并且运行良好。但是当它涉及到android 4.4.4时，它引发了一个异常：

    05-09 13:15:15.030 26447-26447/com.wizchen.athit E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.wizchen.athit, PID: 26447
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.wizchen.athit/com.wizchen.athit.view.activity.MainActivity}: java.lang.NullPointerException
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2271)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2320)
   at android.app.ActivityThread.access$800(ActivityThread.java:138)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1269)
   at android.os.Handler.dispatchMessage(Handler.java:102)
   at android.os.Looper.loop(Looper.java:136)
   at android.app.ActivityThread.main(ActivityThread.java:5117)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:515)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
   at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
   at android.support.v4.graphics.drawable.DrawableWrapperDonut.setCompatTintMode(DrawableWrapperDonut.java:278)
   at android.support.v4.graphics.drawable.DrawableCompatBase.setTintMode(DrawableCompatBase.java:48)
   at android.support.v4.graphics.drawable.DrawableCompat$BaseDrawableImpl.setTintMode(DrawableCompat.java:99)
   at android.support.v4.graphics.drawable.DrawableCompat.setTintMode(DrawableCompat.java:400)
   at com.wizchen.athit.lib.AppThemeEngine.util.TintHelper.createTintedDrawable(TintHelper.java:359)
   at com.wizchen.athit.lib.AppThemeEngine.viewprocessors.ToolbarProcessor.process(ToolbarProcessor.java:117)
   at com.wizchen.athit.lib.AppThemeEngine.viewprocessors.ToolbarProcessor.process(ToolbarProcessor.java:44)
   at com.wizchen.athit.lib.AppThemeEngine.ATE.postApply(ATE.java:209)
   at com.wizchen.athit.lib.AppThemeEngine.ATEActivity.onStart(ATEActivity.java:60)
   at com.wizchen.athit.view.activity.MainActivity.onStart(MainActivity.java:68)
   at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1183)
   at android.app.Activity.performStart(Activity.java:5359)
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2244)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2320) 
   at android.app.ActivityThread.access$800(ActivityThread.java:138) 
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1269) 
   at android.os.Handler.dispatchMessage(Handler.java:102) 
   at android.os.Looper.loop(Looper.java:136) 
   at android.app.ActivityThread.main(ActivityThread.java:5117) 
   at java.lang.reflect.Method.invokeNative(Native Method) 
   at java.lang.reflect.Method.invoke(Method.java:515) 
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) 
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) 
   at dalvik.system.NativeStart.main(Native Method)

除了上面的堆栈跟踪，我在控制台中看到了一些错误信息：

05-09 13:15:15.030 26447-26447/com.wizchen.athit E/dalvikvm: Could not find class 'android.graphics.drawable.RippleDrawable', referenced from method com.wizchen.athit.lib.AppThemeEngine.util.TintHelper.setTintAuto

这一个：

05-09 13:15:15.030 26447-26447/com.wizchen.athit E/dalvikvm: Could not find class 'android.graphics.drawable.RippleDrawable', referenced from method com.wizchen.athit.lib.AppThemeEngine.util.TintHelper.setTintSelector

当然我已经在我的项目中编译了v4支持库：）

谁遇到过这个问题？谢谢你的帮助！

-------------------------------------------- ----------------------------------------------
更新1： 这是导致NullPointerException的原因：

    @CheckResult
    @Nullable
    public static Drawable createTintedDrawable(@Nullable Drawable drawable, @ColorInt int color) {
        if (drawable == null) return null;
        drawable = DrawableCompat.wrap(drawable.mutate());
        DrawableCompat.setTintMode(drawable, PorterDuff.Mode.SRC_IN);
        DrawableCompat.setTint(drawable, color);
        return drawable;
    }

Answer 1

阅读本文：

如果您查看DrawableCompat的源代码，您会看到任何版本的＆lt; support library 21 the method does nothing。

DrawableCompat的想法似乎不是在旧版本上崩溃，而是实际提供该功能。

UseFul Tips：

使用support library 22.1，您可以使用DrawableCompat来设置drawables。

DrawableCompat.wrap（Drawable）和setTint（），setTintList（）和 setTintMode（）将起作用：无需创建和维护单独的 drawables只支持多种颜色！

Answer 2

我使用？colorPrimary在我的项目中创建按钮背景及其故障错误，我将？colorPrimary更改为@ color / colorPrimary并为我工作：）

找不到类＆＃39; android.graphics.drawable.RippleDrawable＆＃39;

2 个答案:

阅读本文：

UseFul Tips：