每当按下按钮时，我都会尝试提示 AlertDialog，但是我只能在三个按钮中的第一个。
添加后:
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强制关闭我知道我忽略了一些简单的事情或者根本没有正确编码。
(非常感谢任何帮助!)
<小时/>JAVA:
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:
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
最佳答案
通过依次调用这些:
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要的工作:
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，您已在 XML 中定义了一个 OnClickListener:
android:onClick="onPopupBtClick"
但未能在您的 Activity 中编写此方法...
public void onPopupBtClick(View view) {
// Do something
}
关于java - 按钮 OnClick 监听器不会调用警报对话框，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15372732/