Android意图应用程序崩溃

Question

我正在尝试为一个项目创建一个非常小的应用程序。我有两个按钮以隐含的意图调用应用程序，但无论何时按下，应用程序（我创建的那个）都会一直崩溃。这是怎么回事？下面的代码：

package com.messengerassist; 

import android.content.Intent; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 

public class MainActivity extends AppCompatActivity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
    } 
    public void startPostmates() { 
     Intent launchIntent = getPackageManager().getLaunchIntentForPackage("com.postmates.android.courier"); 
     startActivity(launchIntent); 
    } 
    public void startCaviar() { 
     Intent launchIntent = getPackageManager().getLaunchIntentForPackage("com.trycaviar.courier"); 
     startActivity(launchIntent); 
    } 
} 

然后

activity_main.xml中：

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    tools:context="com.messengerassist.MainActivity"> 

    <Button 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Start Postmates" 
     android:id="@+id/startPostmates" 
     android:onClick="startPostmates" 
     android:layout_alignParentTop="true" 
     android:layout_centerHorizontal="true" /> 

    <Button 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Start Caviar" 
     android:id="@+id/startCaviar" 
     android:onClick="Start Caviar" 
     android:layout_below="@+id/startPostmates" 
     android:layout_centerHorizontal="true" /> 
</RelativeLayout> 

这里是logcat的是给我：

12-21 20:10:28.919 4108-4108/com.messengerassist E/AndroidRuntime: FATAL EXCEPTION: main 
                    Process: com.messengerassist, PID: 4108 
                    java.lang.IllegalStateException: Could not find method startPostmates(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton with id 'startPostmates' 
                     at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.resolveMethod(AppCompatViewInflater.java:307) 
                     at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:266) 
                     at android.view.View.performClick(View.java:4789) 
                     at android.view.View$PerformClick.run(View.java:19881) 
                     at android.os.Handler.handleCallback(Handler.java:739) 
                     at android.os.Handler.dispatchMessage(Handler.java:95) 
                     at android.os.Looper.loop(Looper.java:135) 
                     at android.app.ActivityThread.main(ActivityThread.java:5292) 
                     at java.lang.reflect.Method.invoke(Native Method) 
                     at java.lang.reflect.Method.invoke(Method.java:372) 
                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904) 
                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699) 

Answer 1

当您注册一个点击监听方法在你的XML中，该方法应该将View作为参数。从logcat改变像这样的方法签名可以解决问题

public void startPostmates(View view) { ...} 
public void startCaviar(View view) {...}