java - 单击按钮时 Android 应用程序崩溃

Question

当我运行应用程序时没有检测到错误，但是当我点击我的按钮时，应用程序崩溃了。我是 Java 和 Android 编程的新手。是不是android:onClick方法错了？

我的 XML 代码:

<?xml version="1.0" encoding="utf-8"?>
<!-- This is BMI page screen -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/numberPickerage"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >
    <!-- text for weight -->
    <TextView
        android:id="@+id/textweight"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textage"
        android:layout_below="@+id/textage"
        android:layout_marginTop="21dp"
        android:labelFor="@+id/weight"
        android:text="@string/bmiweight"
        android:textColor="#000000"
        android:textSize="22sp"
        android:typeface="sans" />
    <!-- text for height -->
    <TextView
        android:id="@+id/textheight"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textweight"
        android:layout_below="@+id/textweight"
        android:layout_marginTop="19dp"
        android:labelFor="@+id/height"
        android:text="@string/bmiheight"
        android:textColor="#000000"
        android:textSize="22sp"
        android:typeface="sans" />
    <!-- text for age -->
    <TextView
        android:id="@+id/textage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/texttitle"
        android:layout_marginLeft="26dp"
        android:layout_marginTop="33dp"
        android:labelFor="@+id/editage"
        android:text="@string/bmiage"
        android:textColor="#000000"
        android:textSize="22sp"
        android:typeface="sans" />

    <EditText
        android:id="@+id/editage"
        android:layout_width="50dp"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textage"
        android:layout_alignBottom="@+id/textage"
        android:layout_alignRight="@+id/textweight"
        android:ems="10"
        android:inputType="numberSigned" >

        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/weight"
        android:layout_width="60dp"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textweight"
        android:layout_alignBottom="@+id/textweight"
        android:layout_marginLeft="14dp"
        android:layout_toRightOf="@+id/textheight"
        android:ems="10"
        android:inputType="numberDecimal" />

    <EditText
        android:id="@+id/height"
        android:layout_width="60dp"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textheight"
        android:layout_alignBottom="@+id/textheight"
        android:layout_alignLeft="@+id/weight"
        android:ems="10"
        android:inputType="numberDecimal" />

    <Button
        android:id="@+id/btnBMIc"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textheight"
        android:layout_below="@+id/height"
        android:layout_marginTop="50dp"
        android:text="@string/bmical"
        android:onClick="calculateBMI" />
    <!-- text for show bmi -->
    <TextView
        android:id="@+id/showBMI"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/weight"
        android:layout_alignRight="@+id/texttitle"
        android:layout_alignTop="@+id/textage"
        android:text="@string/defaultBMI"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:textSize="80sp" />
    <!-- text for title -->
    <TextView
        android:id="@+id/texttitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="23dp"
        android:text="@string/bmihome"
        android:textColor="#000000"
        android:textSize="30sp"
        android:textStyle="bold"
        android:typeface="sans" />

</RelativeLayout>

我的 fragment Java 代码:

package com.our.foodapp;

import com.our.foodapp.R;

import android.annotation.SuppressLint;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

  @SuppressLint("NewApi")
   public class GP_Fragment extends Fragment {

          EditText weights;
          EditText heights;
          Button btnBMI;
          TextView bmiChg;
          public double wei = 0;
          public double hei = 0;

  @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
      {

              View rootView = inflater .inflate(R.layout.gp_fragment, container, false);  


                 //to calculate BMI
                 weights = (EditText)rootView.findViewById(R.id.weight);
                 heights = (EditText)rootView.findViewById(R.id.height);
                 btnBMI = (Button)rootView.findViewById(R.id.btnBMIc);
                 bmiChg = (TextView)rootView.findViewById(R.id.showBMI);
                 return rootView;
              }

            @Override
                public void onViewCreated(View view, Bundle savedInstanceState) {
                    super.onViewCreated(view, savedInstanceState);
                    initializeApp();
            }

                void initializeApp()
                {
                     weights = (EditText)getView().findViewById(R.id.weight);
                     heights = (EditText)getView().findViewById(R.id.height);
                     btnBMI = (Button)getView().findViewById(R.id.btnBMIc);
                     bmiChg = (TextView)getView().findViewById(R.id.showBMI);
                }


               @SuppressLint("DefaultLocale")
            public void calculateBMI(View v)
               {
                    wei = Double.parseDouble(weights.getText().toString() );
                    hei = Double.parseDouble(heights.getText().toString() );
                    double bmi = (wei/(hei * hei))* 703.0;
                    String result = String.format("%.2f",bmi);
                    //Change the default 0
                    bmiChg.setText(result, TextView.BufferType.NORMAL);
               }

      }




07-04 02:26:10.911: W/dalvikvm(26593): No implementation found for native Ldalvik/system/VMRuntime;.pauseGc:(Ljava/lang/String;)I
07-04 02:26:10.911: E/ActivityThread(26593): Pause GC
07-04 02:26:10.911: E/ActivityThread(26593): java.lang.reflect.InvocationTargetException
07-04 02:26:10.911: E/ActivityThread(26593):    at java.lang.reflect.Method.invokeNative(Native Method)
07-04 02:26:10.911: E/ActivityThread(26593):    at java.lang.reflect.Method.invoke(Method.java:515)
07-04 02:26:10.911: E/ActivityThread(26593):    at android.app.ActivityThread.pauseGC(ActivityThread.java:5525)
07-04 02:26:10.911: E/ActivityThread(26593):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2324)
07-04 02:26:10.911: E/ActivityThread(26593):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2471)
07-04 02:26:10.911: E/ActivityThread(26593):    at android.app.ActivityThread.access$900(ActivityThread.java:175)
07-04 02:26:10.911: E/ActivityThread(26593):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1308)
07-04 02:26:10.911: E/ActivityThread(26593):    at android.os.Handler.dispatchMessage(Handler.java:102)
07-04 02:26:10.911: E/ActivityThread(26593):    at android.os.Looper.loop(Looper.java:146)
07-04 02:26:10.911: E/ActivityThread(26593):    at android.app.ActivityThread.main(ActivityThread.java:5602)
07-04 02:26:10.911: E/ActivityThread(26593):    at java.lang.reflect.Method.invokeNative(Native Method)
07-04 02:26:10.911: E/ActivityThread(26593):    at java.lang.reflect.Method.invoke(Method.java:515)
07-04 02:26:10.911: E/ActivityThread(26593):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
07-04 02:26:10.911: E/ActivityThread(26593):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
07-04 02:26:10.911: E/ActivityThread(26593):    at dalvik.system.NativeStart.main(Native Method)
07-04 02:26:10.911: E/ActivityThread(26593): Caused by: java.lang.UnsatisfiedLinkError: Native method not found: dalvik.system.VMRuntime.pauseGc:(Ljava/lang/String;)I
07-04 02:26:10.911: E/ActivityThread(26593):    at dalvik.system.VMRuntime.pauseGc(Native Method)
07-04 02:26:10.911: E/ActivityThread(26593):    ... 15 more
07-04 02:26:11.046: D/dalvikvm(26593): GC_FOR_ALLOC freed 83K, 11% free 8299K/9240K, paused 20ms, total 20ms
07-04 02:26:11.056: I/dalvikvm-heap(26593): Grow heap (frag case) to 15.192MB for 6554896-byte allocation
07-04 02:26:11.076: D/dalvikvm(26593): GC_FOR_ALLOC freed <1K, 7% free 14700K/15644K, paused 20ms, total 20ms
07-04 02:26:11.136: D/libEGL(26593): loaded /system/lib/egl/libEGL_mali.so
07-04 02:26:11.141: D/libEGL(26593): loaded /system/lib/egl/libGLESv1_CM_mali.so
07-04 02:26:11.146: D/libEGL(26593): loaded /system/lib/egl/libGLESv2_mali.so
07-04 02:26:11.151: E/(26593): Device driver API match
07-04 02:26:11.151: E/(26593): Device driver API version: 23
07-04 02:26:11.151: E/(26593): User space API version: 23 
07-04 02:26:11.151: E/(26593): mali: REVISION=Linux-r3p2-01rel3 BUILD_DATE=Fri Mar 21 13:52:50 KST 2014 
07-04 02:26:11.241: D/OpenGLRenderer(26593): Enabling debug mode 0
07-04 02:26:11.346: W/dalvikvm(26593): No implementation found for native Ldalvik/system/VMRuntime;.pauseGc:(Ljava/lang/String;)I
07-04 02:26:11.351: E/ActivityThread(26593): Pause GC
07-04 02:26:11.351: E/ActivityThread(26593): java.lang.reflect.InvocationTargetException
07-04 02:26:11.351: E/ActivityThread(26593):    at java.lang.reflect.Method.invokeNative(Native Method)
07-04 02:26:11.351: E/ActivityThread(26593):    at java.lang.reflect.Method.invoke(Method.java:515)
07-04 02:26:11.351: E/ActivityThread(26593):    at android.app.ActivityThread.pauseGC(ActivityThread.java:5525)
07-04 02:26:11.351: E/ActivityThread(26593):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2324)
07-04 02:26:11.351: E/ActivityThread(26593):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2471)
07-04 02:26:11.351: E/ActivityThread(26593):    at android.app.ActivityThread.access$900(ActivityThread.java:175)
07-04 02:26:11.351: E/ActivityThread(26593):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1308)
07-04 02:26:11.351: E/ActivityThread(26593):    at android.os.Handler.dispatchMessage(Handler.java:102)
07-04 02:26:11.351: E/ActivityThread(26593):    at android.os.Looper.loop(Looper.java:146)
07-04 02:26:11.351: E/ActivityThread(26593):    at android.app.ActivityThread.main(ActivityThread.java:5602)
07-04 02:26:11.351: E/ActivityThread(26593):    at java.lang.reflect.Method.invokeNative(Native Method)
07-04 02:26:11.351: E/ActivityThread(26593):    at java.lang.reflect.Method.invoke(Method.java:515)
07-04 02:26:11.351: E/ActivityThread(26593):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
07-04 02:26:11.351: E/ActivityThread(26593):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
07-04 02:26:11.351: E/ActivityThread(26593):    at dalvik.system.NativeStart.main(Native Method)
07-04 02:26:11.351: E/ActivityThread(26593): Caused by: java.lang.UnsatisfiedLinkError: Native method not found: dalvik.system.VMRuntime.pauseGc:(Ljava/lang/String;)I
07-04 02:26:11.351: E/ActivityThread(26593):    at dalvik.system.VMRuntime.pauseGc(Native Method)
07-04 02:26:11.351: E/ActivityThread(26593):    ... 15 more
07-04 02:26:11.466: D/dalvikvm(26593): GC_FOR_ALLOC freed 88K, 6% free 14829K/15776K, paused 13ms, total 13ms
07-04 02:26:11.476: I/dalvikvm-heap(26593): Grow heap (frag case) to 21.569MB for 6554896-byte allocation
07-04 02:26:11.491: D/dalvikvm(26593): GC_FOR_ALLOC freed <1K, 5% free 21230K/22180K, paused 14ms, total 14ms
07-04 02:26:11.516: D/AbsListView(26593): Get MotionRecognitionManager
07-04 02:26:11.556: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.561: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.561: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.561: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.661: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.671: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.676: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.746: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.746: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.746: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:11.751: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.041: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.046: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.046: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.431: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.436: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.656: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.661: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.716: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.716: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.716: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.716: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.721: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.721: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.731: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.731: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.731: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.736: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.736: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:14.736: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:16.891: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:17.096: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:18.131: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:18.336: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:18.611: D/TextLayoutCache(26593): Enable myanmar Zawgyi converter
07-04 02:26:19.436: D/AndroidRuntime(26593): Shutting down VM
07-04 02:26:19.436: W/dalvikvm(26593): threadid=1: thread exiting with uncaught exception (group=0x41c5bc08)
07-04 02:26:19.436: E/AndroidRuntime(26593): FATAL EXCEPTION: main
07-04 02:26:19.436: E/AndroidRuntime(26593): Process: com.our.foodapp, PID: 26593
07-04 02:26:19.436: E/AndroidRuntime(26593): java.lang.IllegalStateException: Could not find a method calculateBMI(View) in the activity class com.our.foodapp.Ourfood for onClick handler on view class android.widget.Button with id 'btnBMIc'
07-04 02:26:19.436: E/AndroidRuntime(26593):    at android.view.View$1.onClick(View.java:3970)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at android.view.View.performClick(View.java:4654)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at android.view.View$PerformClick.run(View.java:19438)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at android.os.Handler.handleCallback(Handler.java:733)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at android.os.Handler.dispatchMessage(Handler.java:95)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at android.os.Looper.loop(Looper.java:146)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at android.app.ActivityThread.main(ActivityThread.java:5602)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at java.lang.reflect.Method.invokeNative(Native Method)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at java.lang.reflect.Method.invoke(Method.java:515)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at dalvik.system.NativeStart.main(Native Method)
07-04 02:26:19.436: E/AndroidRuntime(26593): Caused by: java.lang.NoSuchMethodException: calculateBMI [class android.view.View]
07-04 02:26:19.436: E/AndroidRuntime(26593):    at java.lang.Class.getConstructorOrMethod(Class.java:472)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at java.lang.Class.getMethod(Class.java:857)
07-04 02:26:19.436: E/AndroidRuntime(26593):    at android.view.View$1.onClick(View.java:3963)
07-04 02:26:19.436: E/AndroidRuntime(26593):    ... 11 more
07-04 02:26:21.981: I/Process(26593): Sending signal. PID: 26593 SIG: 9

抱歉没有发布 logcat。将它与 java 代码一起附加。

Answer 1

当你在 XML 上放置一个 android:onClick 时，你需要在你的 Activity 上有一个同名的方法来处理它......不是在你的 View 或 Fragment 上，而是在 Acitivy 上。

我还建议你阅读堆栈跟踪，这个解释也在那里。