嘿伙计们我正在创建一个Android应用程序(我是非常新的),我在点击登录按钮后尝试访问一个新的活动窗口,但是一旦我点击它,一个窗口弹出,说“不幸”appname“已经停止”并退出程序。这是我的代码,你能看出它有什么问题吗?谢谢你们
这是Login Class.java文件
package com.example.smartsignoutv3;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class LoginScreen extends Activity implements OnClickListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_screen);
((Button)findViewById(R.id.sign_in_button)).setOnClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_login_screen, menu);
return true;
}
@Override
public void onClick(View arg0) {
switch (arg0.getId()) {
case (R.id.sign_in_button): {
System.out.println("yo dawg");
Intent i = new Intent(this, MainScreen.class);
startActivity(i);
return;
}
}
}
}
以下是我点击登录按钮后要打开的主要活动屏幕
package com.example.smartsignoutv3;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
public class MainScreen extends Activity {
private static final int SWIPE_MIN_DISTANCE = 120;
private static final int SWIPE_MAX_OFF_PATH = 250;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;
private GestureDetector gestureDetector;
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_screen);
gestureDetector = new GestureDetector(new MyGestureDetector());
View mainview = (View) findViewById(R.id.welcome_screen);
// Set the touch listener for the main view to be our custom gesture listener
mainview.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
if (gestureDetector.onTouchEvent(event)) {
return true;
}
return false;
}
});
}
class MyGestureDetector extends SimpleOnGestureListener {
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
Intent intent = new Intent(MainScreen.this.getBaseContext(), MainScreen.class);
if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH) {
return false;
}
// right to left swipe
if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
startActivity(intent);
MainScreen.this.overridePendingTransition(
R.anim.slide_in_right,
R.anim.slide_out_left
);
// right to left swipe
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
startActivity(intent);
MainScreen.this.overridePendingTransition(
R.anim.slide_in_left,
R.anim.slide_out_right
);
}
return false;
}
// It is necessary to return true from onDown for the onFling event to register
@Override
public boolean onDown(MotionEvent e) {
return true;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_login_screen, menu);
return true;
}
}
如果需要,这里是android清单文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.smartsignoutv3"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.smartsignoutv3.LoginScreen"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.smartsignoutv3.MainScreen"
android:label="@string/app_name">
</activity>
</application>
答案 0 :(得分:1)
从此
更改LoginScreen活动的onCreate@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_screen);
((Button)findViewById(R.id.sign_in_button)).setOnClickListener(this);
}
到此
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_screen);
button = (Button)findViewById(R.id.sign_in_button).setOnClickListener(this);
}
在你的onClick中直接执行此操作
@Override
public void onClick(View arg0) {
switch (arg0.getId()) {
case R.id.sign_in_button:
System.out.println("yo dawg");
Intent i = new Intent(this, MainScreen.class);
startActivity(i);
break;
}
return true;
}
答案 1 :(得分:1)
在LoginScreen
活动中,您有
setContentView(R.layout.activity_login_screen);
在您的MainScreen
活动中,您有
setContentView(R.layout.activity_login_screen);
MainScreen
应该有不同的布局。