Question

我正在使用一个按钮来切换活动，但是logcat说我还没有在我的AndroidManifest.xml中宣布我的活动至少检查了五次，而且它就在那里。我试图切换到fahrenheittocelsius类。

带有按钮的主要java页面在这里：

package com.jordandebarth.supercalculator;


import com.jordandebarth.supercalculator.distance;
import com.jordandebarth.supercalculator.exponents;
import com.jordandebarth.supercalculator.nuclearfusion;
import com.jordandebarth.supercalculator.pythagorean;
import com.jordandebarth.supercalculator.fahrenheittocelsius;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.support.v4.app.NavUtils;


public class tab_view extends Activity {

    Button calculator, pythagorean, distance, exponent, temperature, nuclearfusion;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_tab_view);
        calculator = (Button)findViewById(R.id.calculatorButton);
        pythagorean = (Button)findViewById(R.id.pythagoreanButton);
        distance = (Button)findViewById(R.id.distanceButton);
        exponent = (Button)findViewById(R.id.exponentsButton);
        temperature = (Button)findViewById(R.id.temperatureButton);
        nuclearfusion = (Button)findViewById(R.id.nuclearfusion);


        pythagorean.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent pythagoreanIntent = new Intent(getBaseContext(), pythagorean.class);
                startActivityForResult(pythagoreanIntent, 0);
                overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);
            }
        });
        distance.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent distanceIntent = new Intent(getBaseContext(), distance.class);
                startActivityForResult(distanceIntent, 0);
                overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);
            }
        });
        exponent.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent exponentIntent = new Intent(getBaseContext(), exponents.class);
                startActivityForResult(exponentIntent, 0);
                overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);
            }
        });
        temperature.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent temperatureIntent = new Intent(getBaseContext(), fahrenheittocelsius.class);
                startActivityForResult(temperatureIntent, 0);
                overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);
            }
        });
        nuclearfusion.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent nuclearfusionIntent = new Intent(getBaseContext(), nuclearfusion.class);
                startActivityForResult(nuclearfusionIntent, 0);
                overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);
            }
        });

    }




}

我的AndroidManifest是：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.jordandebarth.supercalculator"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".tab_view"
            android:label="@string/title_activity_tab_view" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
       <activty
            android:name=".fahrenheittocelsius"
            android:label="Fahrenheit to Celsius"
            ></activty>

        <activity
            android:name=".calculator"
            android:label="Calculator"  >
        </activity>
        <activity
            android:name=".pythagorean"
            android:label="Pythagorean Theorem"
            >

        </activity>
        <activity
            android:name=".distance"
            android:label="Distance Formula"
            ></activity>
        <activity 
            android:name=".exponents"
            android:label="Exponents"
            ></activity>

        <activity
            android:name=".nuclearfusion"
            android:label="Nuclear Fusion"
            ></activity>
    </application>


</manifest>

Answer 1

将getBaseContext()的所有实例替换为tab_view.this。

Answer 2

startActivityForResult允许您启动活动并获取一些数据。想象一下，你有一些文件选择器活动。按照答案链接。而且，如果您使用startActivityForResult()，则需要onActivityResult()

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // Result OK.d.
    if (requestCode == resultCode) {
        // do something good
    }
}

尝试使用以下代码开始您的活动 -

Intent temperature = new Intent(tab_view.this, fahrenheittocelsius.class);
startActivity(temperature);
overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);

强制关闭活动开关

2 个答案: