Snackbar不適用於API 17

Question

我想從支持庫中使用Snackbar，但是當我在API低於21的模擬器上進行應用程序午餐時，應用程序會粉碎。 我認爲支持庫會使小吃店在舊版本上工作，這是否正確？

搖籃：

apply plugin: 'com.android.application' 

android { 
    compileSdkVersion 25 
    buildToolsVersion "25.0.2" 
    defaultConfig { 
     applicationId "com.example.user.test" 
     minSdkVersion 15 
     targetSdkVersion 25 
     versionCode 1 
     versionName "1.0" 
     testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" 
    } 
    buildTypes { 
     release { 
      minifyEnabled false 
      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
     } 
    } 
} 

dependencies { 
    compile fileTree(include: ['*.jar'], dir: 'libs') 
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', { 
     exclude group: 'com.android.support', module: 'support-annotations' 
    }) 
    compile 'com.android.support:appcompat-v7:25.2.0' 
    testCompile 'junit:junit:4.12' 
    compile 'com.android.support:design:25.2.0' 
    compile 'com.automationrockstars:design:1.0.3' 
} 

MainActivity.java

package com.example.user.test; 

import android.support.design.widget.Snackbar; 
import android.os.Bundle; 
import android.support.v7.app.AppCompatActivity; 
import android.widget.LinearLayout; 

public class MainActivity extends AppCompatActivity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

    } 

    @Override 
    protected void onStart() { 
     super.onStart(); 
     LinearLayout l = (LinearLayout) findViewById(R.id.linear1); 
     Snackbar snackbar = Snackbar.make(l,"Hello",Snackbar.LENGTH_LONG); 
     snackbar.show(); 
    } 
} 

編輯（在logcat的）

03-04 18:54:49.827 1468-1468/? D/dalvikvm: Late-enabling CheckJNI 
03-04 18:54:49.911 1468-1474/? E/jdwp: Failed sending reply to debugger: Broken pipe 
03-04 18:54:49.911 1468-1474/? D/dalvikvm: Debugger has detached; object registry had 1 entries 
03-04 18:54:49.939 1468-1468/? I/dalvikvm: Could not find method android.view.Window$Callback.onProvideKeyboardShortcuts, referenced from method android.support.v7.view.WindowCallbackWrapper.onProvideKeyboardShortcuts 
03-04 18:54:49.951 1468-1468/? W/dalvikvm: VFY: unable to resolve interface method 20911: Landroid/view/Window$Callback;.onProvideKeyboardShortcuts (Ljava/util/List;Landroid/view/Menu;I)V 
03-04 18:54:49.951 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002 
03-04 18:54:49.955 1468-1468/? W/dalvikvm: VFY: unable to find class referenced in signature (Landroid/view/SearchEvent;) 
03-04 18:54:49.959 1468-1468/? I/dalvikvm: Could not find method android.view.Window$Callback.onSearchRequested, referenced from method android.support.v7.view.WindowCallbackWrapper.onSearchRequested 
03-04 18:54:49.963 1468-1468/? W/dalvikvm: VFY: unable to resolve interface method 20913: Landroid/view/Window$Callback;.onSearchRequested (Landroid/view/SearchEvent;)Z 
03-04 18:54:49.963 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002 
03-04 18:54:49.963 1468-1468/? I/dalvikvm: Could not find method android.view.Window$Callback.onWindowStartingActionMode, referenced from method android.support.v7.view.WindowCallbackWrapper.onWindowStartingActionMode 
03-04 18:54:49.963 1468-1468/? W/dalvikvm: VFY: unable to resolve interface method 20917: Landroid/view/Window$Callback;.onWindowStartingActionMode (Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode; 
03-04 18:54:49.963 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x72 at 0x0002 
03-04 18:54:49.963 1468-1468/? I/dalvikvm: Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.widget.TintTypedArray.getChangingConfigurations 
03-04 18:54:49.963 1468-1468/? W/dalvikvm: VFY: unable to resolve virtual method 487: Landroid/content/res/TypedArray;.getChangingConfigurations()I 
03-04 18:54:49.963 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002 
03-04 18:54:49.963 1468-1468/? I/dalvikvm: Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.widget.TintTypedArray.getType 
03-04 18:54:49.967 1468-1468/? W/dalvikvm: VFY: unable to resolve virtual method 509: Landroid/content/res/TypedArray;.getType (I)I 
03-04 18:54:49.967 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0008 
03-04 18:54:50.059 1468-1468/? I/dalvikvm: Could not find method android.widget.FrameLayout.startActionModeForChild, referenced from method android.support.v7.widget.ActionBarContainer.startActionModeForChild 
03-04 18:54:50.059 1468-1468/? W/dalvikvm: VFY: unable to resolve virtual method 21394: Landroid/widget/FrameLayout;.startActionModeForChild (Landroid/view/View;Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode; 
03-04 18:54:50.063 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x6f at 0x0002 
03-04 18:54:50.071 1468-1468/? I/dalvikvm: Could not find method android.content.Context.getColorStateList, referenced from method android.support.v7.content.res.AppCompatResources.getColorStateList 
03-04 18:54:50.087 1468-1468/? W/dalvikvm: VFY: unable to resolve virtual method 301: Landroid/content/Context;.getColorStateList (I)Landroid/content/res/ColorStateList; 
03-04 18:54:50.087 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0006 
03-04 18:54:50.095 1468-1468/? I/dalvikvm: Could not find method android.content.res.Resources.getDrawable, referenced from method android.support.v7.widget.ResourcesWrapper.getDrawable 
03-04 18:54:50.095 1468-1468/? W/dalvikvm: VFY: unable to resolve virtual method 450: Landroid/content/res/Resources;.getDrawable (ILandroid/content/res/Resources$Theme;)Landroid/graphics/drawable/Drawable; 
03-04 18:54:50.095 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002 
03-04 18:54:50.095 1468-1468/? I/dalvikvm: Could not find method android.content.res.Resources.getDrawableForDensity, referenced from method android.support.v7.widget.ResourcesWrapper.getDrawableForDensity 
03-04 18:54:50.095 1468-1468/? W/dalvikvm: VFY: unable to resolve virtual method 452: Landroid/content/res/Resources;.getDrawableForDensity (IILandroid/content/res/Resources$Theme;)Landroid/graphics/drawable/Drawable; 
03-04 18:54:50.095 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002 
03-04 18:54:50.107 1468-1468/? E/dalvikvm: Could not find class 'android.graphics.drawable.RippleDrawable', referenced from method android.support.v7.widget.AppCompatImageHelper.hasOverlappingRendering 
03-04 18:54:50.107 1468-1468/? W/dalvikvm: VFY: unable to resolve instanceof 146 (Landroid/graphics/drawable/RippleDrawable;) in Landroid/support/v7/widget/AppCompatImageHelper; 
03-04 18:54:50.107 1468-1468/? D/dalvikvm: VFY: replacing opcode 0x20 at 0x000c 
03-04 18:54:50.187 1468-1471/? D/dalvikvm: GC_CONCURRENT freed 188K, 10% free 2682K/2980K, paused 2ms+1ms, total 62ms 
03-04 18:54:50.187 1468-1468/? D/dalvikvm: WAIT_FOR_CONCURRENT_GC blocked 57ms 
03-04 18:54:50.187 1468-1468/? D/AndroidRuntime: Shutting down VM 
03-04 18:54:50.187 1468-1468/? W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0xa61fe908) 
03-04 18:54:50.191 1468-1468/? E/AndroidRuntime: FATAL EXCEPTION: main 
               java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.user.test/com.example.user.test.MainActivity}: java.lang.NullPointerException 
                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180) 
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230) 
                at android.app.ActivityThread.access$600(ActivityThread.java:141) 
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234) 
                at android.os.Handler.dispatchMessage(Handler.java:99) 
                at android.os.Looper.loop(Looper.java:137) 
                at android.app.ActivityThread.main(ActivityThread.java:5041) 
                at java.lang.reflect.Method.invokeNative(Native Method) 
                at java.lang.reflect.Method.invoke(Method.java:511) 
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
                at dalvik.system.NativeStart.main(Native Method) 
                Caused by: java.lang.NullPointerException 
                at android.support.design.widget.Snackbar.make(Snackbar.java:136) 
                at com.example.user.test.MainActivity.onStart(MainActivity.java:21) 
                at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1164) 
                at android.app.Activity.performStart(Activity.java:5114) 
                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2153) 
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)  
                at android.app.ActivityThread.access$600(ActivityThread.java:141)  
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)  
                at android.os.Handler.dispatchMessage(Handler.java:99)  
                at android.os.Looper.loop(Looper.java:137)  
                at android.app.ActivityThread.main(ActivityThread.java:5041)  
                at java.lang.reflect.Method.invokeNative(Native Method)  
                at java.lang.reflect.Method.invoke(Method.java:511)  
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)  
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)  
                at dalvik.system.NativeStart.main(Native Method)  

Answer 1

試試這個代碼：android.R.id.content

Snackbar.make(findViewById(android.R.id.content), "Hello", Snackbar.LENGTH_LONG).show();