java - 按钮 OnClick 侦听器不会调用警报对话框

Question

我试图在AlertDialog按下按钮时提示一个按钮，但是我只能在AlertDialog三个按钮中的第一个上成功实现（使用教程）成功。

一旦我添加：

button = (Button) findViewById(R.id.button2);
button = (Button) findViewById(R.id.button3);

所有按钮都不再起作用并且应用程序关闭我知道我忽略了一些简单的东西或者根本没有正确编码。

（任何帮助是极大的赞赏！）

爪哇：

package com.example.linkingmanager;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class AppActivity extends Activity {

public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main, menu);
    return true;
}

 public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.newdevicebtn:
        startActivity(new Intent(this, App2Activity.class));
        return true;
        default:
        return super.onOptionsItemSelected(item);
        }   
     }

final Context context = this;
private Button button;
@Override
public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.main);

button = (Button) findViewById(R.id.button1);
button = (Button) findViewById(R.id.button2);
button = (Button) findViewById(R.id.button3);

// add button listener
button.setOnClickListener(new OnClickListener(){

@Override
public void onClick(View arg0) {

    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
        context);

    // set title
    alertDialogBuilder.setTitle("Settings Menu");

    // set dialog message
    alertDialogBuilder
        .setMessage("Delete Edit or Link?")
        .setCancelable(false)
         .setNeutralButton("Edit", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
        //start new activity
     Intent intentApp2Activity = new Intent(AppActivity.this, User1Settings.class);
     startActivity(intentApp2Activity);

}
  })
        .setPositiveButton("Link",new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog,int id) {
        //start new activity

        Intent intentApp2Activity = new Intent(AppActivity.this, User1.class);
        startActivity(intentApp2Activity);

        // if this button is clicked, close
        // current activity
        AppActivity.this.finish();
    }
  })    
        .setNegativeButton("Delete",new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int id) {
                // if this button is clicked, just close
                // the dialog box and do nothing
                dialog.cancel();
            }
        });

        // create alert dialog
        AlertDialog alertDialog = alertDialogBuilder.create();

        // show it
        alertDialog.show();
    }
});
}}

XML:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/link_devices"
android:orientation="vertical" >

 <TextView android:textAppearance="?android:textAppearanceLarge" android:id="@+id/textView1"    android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="" />
<Button android:id="@+id/button1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Core Device 1" android:onClick="onPopupBtClick" />
 <Button android:id="@+id/button2" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Core Device 2" android:onClick="onPopupBtClick" />
<Button android:id="@+id/button3" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Core Device 3" android:onClick="onPopupBtClick" />
</LinearLayout>

日志猫：

03-12 21:22:28.194: E/Trace(1648): error opening trace file: No such file or directory (2)
03-12 21:22:28.714: D/dalvikvm(1648): GC_FOR_ALLOC freed 64K, 8% free 2467K/2676K, paused 83ms, total 86ms
03-12 21:22:28.794: I/dalvikvm-heap(1648): Grow heap (frag case) to 6.062MB for 3686416-byte allocation
03-12 21:22:28.854: D/dalvikvm(1648): GC_FOR_ALLOC freed 2K, 4% free 6065K/6280K, paused 53ms, total 53ms
03-12 21:22:28.971: D/dalvikvm(1648): GC_CONCURRENT freed <1K, 4% free 6065K/6280K, paused 8ms+7ms, total 118ms
03-12 21:22:30.784: D/libEGL(1648): loaded /system/lib/egl/libEGL_emulation.so
03-12 21:22:30.793: D/(1648): HostConnection::get() New Host Connection established 0x2a1a5180, tid 1648
03-12 21:22:30.885: D/libEGL(1648): loaded /system/lib/egl/libGLESv1_CM_emulation.so
03-12 21:22:30.904: D/libEGL(1648): loaded /system/lib/egl/libGLESv2_emulation.so
03-12 21:22:31.024: W/EGL_emulation(1648): eglSurfaceAttrib not implemented
03-12 21:22:31.055: D/OpenGLRenderer(1648): Enabling debug mode 0
03-12 21:22:32.973: D/dalvikvm(1648): GC_FOR_ALLOC freed 12K, 3% free 6125K/6280K, paused 84ms, total 99ms
03-12 21:22:33.063: I/dalvikvm-heap(1648): Grow heap (frag case) to 9.634MB for 3686416-byte allocation
03-12 21:22:33.333: D/dalvikvm(1648): GC_CONCURRENT freed 2K, 2% free 9722K/9884K, paused 110ms+8ms, total    261ms
03-12 21:22:35.783: W/EGL_emulation(1648): eglSurfaceAttrib not implemented
03-12 21:25:49.243: D/AndroidRuntime(1648): Shutting down VM
03-12 21:25:49.243: W/dalvikvm(1648): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
03-12 21:25:49.393: E/AndroidRuntime(1648): FATAL EXCEPTION: main
03-12 21:25:49.393: E/AndroidRuntime(1648): java.lang.IllegalStateException: Could not find a method    onPopupBtClick(View) in the activity class com.example.linkingmanager.AppActivity for onClick handler on view class   android.widget.Button with id 'button1'
03-12 21:25:49.393: E/AndroidRuntime(1648):     at android.view.View$1.onClick(View.java:3586)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at android.view.View.performClick(View.java:4204)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at android.view.View$PerformClick.run(View.java:17355)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at android.os.Handler.handleCallback(Handler.java:725)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at android.os.Handler.dispatchMessage(Handler.java:92)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at android.os.Looper.loop(Looper.java:137)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at  android.app.ActivityThread.main(ActivityThread.java:5041)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at java.lang.reflect.Method.invokeNative(Native Method)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at java.lang.reflect.Method.invoke(Method.java:511)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at dalvik.system.NativeStart.main(Native Method)
03-12 21:25:49.393: E/AndroidRuntime(1648): Caused by: java.lang.NoSuchMethodException: onPopupBtClick [class android.view.View]
03-12 21:25:49.393: E/AndroidRuntime(1648):     at java.lang.Class.getConstructorOrMethod(Class.java:460)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at java.lang.Class.getMethod(Class.java:915)
03-12 21:25:49.393: E/AndroidRuntime(1648):     at android.view.View$1.onClick(View.java:3579)
03-12 21:25:49.393: E/AndroidRuntime(1648):     ... 11 more

score 3 · Accepted Answer

通过一个接一个地调用它们：

button = (Button) findViewById(R.id.button1);
button = (Button) findViewById(R.id.button2); // This obliterates the previous value of button
button = (Button) findViewById(R.id.button3); // This obliterates the previous value of button

您正在覆盖先前的变量。要么使用不同的变量，要么在覆盖它的值之前做你想做的工作：

button = (Button) findViewById(R.id.button1);
button.setOnClickListener(mOnClickListener);
//etc.

button = (Button) findViewById(R.id.button2);
button.setOnClickListener(mOnClickListener);
//etc.

就您看到的错误而言，您已经在 XML 中定义了一个 OnClickListener：

android:onClick="onPopupBtClick"

但未能在您的活动中编写此方法...

public void onPopupBtClick(View view) {
    // Do something
}

score 2 · Accepted Answer

从 xml 视图中移除 onPopupBtClick。它在您的活动中找不到名为 onPopupBtClick 的方法，因此崩溃

此外，您不能将 3 个不同的视图分配给同一个 Button 变量。

score 0 · Accepted Answer

public class MainActivity extends Activity {
private Button button1,button2,button3;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    button1 = (Button) findViewById(R.id.button1);
    button2 = (Button) findViewById(R.id.button2);
    button3 = (Button) findViewById(R.id.button3);

    /*
     * Implementation for dynamic OnClicklisteners
     */
//      button1.setOnClickListener(new OnClickListener(){
//          @Override
//          public void onClick(View v) {
//              openDialog(v);
//          }
//      });
//      button2.setOnClickListener(new OnClickListener(){
//          @Override
//          public void onClick(View v) {
//              openDialog(v);
//          }
//      });
//      button3.setOnClickListener(new OnClickListener(){
//          @Override
//          public void onClick(View v) {
//              openDialog(v);
//          }
//      });

}
public void openDialog(View v){
    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this)
    .setTitle("Settings Menu")
    .setMessage("Delete Edit or Link?")
    .setCancelable(false)
    .setNeutralButton("Edit", new DialogInterface.OnClickListener() {
         public void onClick(DialogInterface dialog,int id) {
             Toast.makeText(MainActivity.this, "Clicked Edit",Toast.LENGTH_LONG).show();
         }
    })
    .setPositiveButton("Link",new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,int id) {
            Toast.makeText(MainActivity.this, "Clicked Link",Toast.LENGTH_LONG).show();
        }
    })    
    .setNegativeButton("Delete",new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,int id) {

            dialog.cancel();
        }
     });

    AlertDialog alertDialog = alertDialogBuilder.create();

    alertDialog.show();
}        





<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFF"
android:orientation="vertical" >

<TextView 
    android:textAppearance="?android:textAppearanceLarge" 
    android:id="@+id/textView1"    
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="" />
<Button android:id="@+id/button1" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Core Device 1" 
    android:onClick="openDialog" />
<Button android:id="@+id/button2" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Core Device 2" 
    android:onClick="openDialog" />
<Button android:id="@+id/button3" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Core Device 3" 
    android:onClick="openDialog" />
</LinearLayout>

您可以在https://github.com/darussian/SimpleAndroidDialogExample查看源代码

java - 按钮 OnClick 侦听器不会调用警报对话框

爪哇：

XML:

日志猫：

3 回答 3

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