我有MainActivity.class我已经创建了弹出菜单＆amp;有几个按钮我需要的是我需要将用户发送到我创建的新活动。我的代码是在MainActivity.xml上创建的工作按钮但是当我给弹出菜单按钮id它没有启动我的应用程序。 期待着支持。
package com.example.sampathmunaweera.mobilecw;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.view.View.OnClickListener;
import android.view.View;
import android.app.Activity;
import android.content.Context;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.widget.PopupWindow;
import android.widget.RelativeLayout;
import android.view.ViewGroup.LayoutParams;
import android.widget.PopupMenu;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnexit = (Button) findViewById(R.id.exit);
btnexit.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// exit from app
finish();
System.exit(0);
}
});
// end exit function
final Button btnOpenPopup = (Button)findViewById(R.id.about);
btnOpenPopup.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
LayoutInflater layoutInflater
= (LayoutInflater)getBaseContext()
.getSystemService(LAYOUT_INFLATER_SERVICE);
View popupView = layoutInflater.inflate(R.layout.popup_about, null);
final PopupWindow popupWindow = new PopupWindow(
popupView,
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
Button btnDismiss = (Button)popupView.findViewById(R.id.dismiss);
btnDismiss.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
popupWindow.dismiss();
}});
//popupWindow.showAsDropDown(btnOpenPopup, 50, 50);
popupWindow.showAtLocation(btnOpenPopup, Gravity.CENTER, 0, 0);
}});
//pop up new game
final Button btnNewPopup = (Button)findViewById(R.id.newgame);
btnNewPopup.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
LayoutInflater layoutInflater
= (LayoutInflater)getBaseContext()
.getSystemService(LAYOUT_INFLATER_SERVICE);
View popupView = layoutInflater.inflate(R.layout.popup_newgame, null);
final PopupWindow popupWindow = new PopupWindow(
popupView,
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
Button btnDismiss = (Button)popupView.findViewById(R.id.dismiss);
btnDismiss.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
popupWindow.dismiss();
}});
//popupWindow.showAsDropDown(btnOpenPopup, 50, 50);
popupWindow.showAtLocation(btnOpenPopup, Gravity.CENTER, 0, 0);
}});
//open new activity
final Button btnNewNovise = (Button)findViewById(R.id.Novice);
btnNewNovise.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
Intent myIntent = new Intent(MainActivity.this,
GameController.class);
startActivity(myIntent);
}});
}
public void openNewActivity (View view) {
}
}
弹出菜单xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="@android:color/background_light">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_margin="1dp"
android:background="@android:color/darker_gray">
>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_margin="20dp">
<TextView
android:id="@+id/texttitle1"
android:textStyle="bold"
android:textSize="25dp"
android:textColor="#891800"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Select Game Level" />
<Button
android:id="@+id/Novice"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="openNewActivity"
android:text="Novice" />
<Button
android:id="@+id/Easy"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Easy" />
<Button
android:id="@+id/Hard"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Hard" />
<Button
android:id="@+id/Guru"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Guru" />
<Button
android:id="@+id/dismiss"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Back to Menu" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
AndroidManifest Code
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.sampathmunaweera.mobilecw">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:installLocation="preferExternal"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:label="@string/app_name"
android:name=".GameController"
android:windowSoftInputMode="stateHidden"></activity>
</application>
</manifest>
logcat Erorr
03-06 14:19:20.982 4792-4792/com.example.sampathmunaweera.mobilecw E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.sampathmunaweera.mobilecw, PID: 4792
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sampathmunaweera.mobilecw/com.example.sampathmunaweera.mobilecw.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at com.example.sampathmunaweera.mobilecw.MainActivity.onCreate(MainActivity.java:117)
at android.app.Activity.performCreate(Activity.java:5990)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
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:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
答案 0 :(得分：2)
May get the question wrong but was able to call GameController activity from button in you popmenu xml:
`<Button
android:id="@+id/Novice"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="openNewActivity"
android:text="Novice" />`
just added these lines : `public void openNewActivity (View view) {
if(view.getId()==R.id.Novice){
startActivity(new Intent(this,GameController.class));
}
}`
in main activity
答案 1 :(得分：1)
final Button btnNewPopup = (Button) findViewById(R.id.newgame);
btnNewPopup.setOnClickListener(new OnClickListener() {
@Override public void onClick (View arg0){
...
View popupView = layoutInflater.inflate(R.layout.popup_newgame, null);
...
final Button btnNewNovise = (Button) popupView.findViewById(R.id.Novice);
btnNewNovise.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent myIntent = new Intent(MainActivity.this, GameController.class);
startActivity(myIntent);
}
});
}
});
答案 2 :(得分：1)
您必须在意图
后关闭弹出窗口 V1 V2 V3 V4
rs200140498 chr1 861315 GG
rs371217242 chr1 861329 --
rs200686669 chr1 861349 CC
rs370046315 chr1 861357 CC
rs374110379 chr1 861521 --
rs74045401 chr1 861530 GG
rs377418023 chr1 865394 CC
rs79027658 chr1 865438 --
rs202189913 chr1 865488 AA
rs370992396 chr1 865543 GG
答案 3 :(得分：0)
openNewActivity（）是emty。改变这个
<Button
android:id="@+id/Novice"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:onClick="openNewActivity"
android:text="Novice" />
用这个
<Button
android:id="@+id/Novice"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Novice" />