[当我尝试为每个活动在AndroidManifest.xml中给不同的标题时，应用会显示所有子活动的第一个标题，而不是给定标题。我是编码方面的新手，很抱歉为我的问题提供了错误的解释。代码如下：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android.miwok">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
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:name=".NumbersActivity"
android:label="@string/category_numbers" />
<activity
android:name=".FamilyActivity"
android:label="@string/category_family" />
<activity
android:name=".ColorsActivity"
android:label="@string/category_colors" />
<activity
android:name=".PhrasesActivity"
android:label="@string/category_phrases" />
</application>
</manifest>
我该如何解决？
更新：为了更加清楚，我正在添加我的MainActivity代码：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set the content of the activity to use the activity_main.xml layout file
setContentView(R.layout.activity_main);
TextView numbers = (TextView) findViewById(R.id.numbers);
TextView colors = (TextView) findViewById(R.id.colors);
TextView family = (TextView) findViewById(R.id.family);
TextView phrases = (TextView) findViewById(R.id.phrases);
assert numbers != null;
numbers.setOnClickListener(this);
assert colors != null;
colors.setOnClickListener(this);
assert family != null;
family.setOnClickListener(this);
assert phrases != null;
phrases.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.numbers:
Intent numberIntent = new Intent(MainActivity.this,NumbersActivity.class);
startActivity(numberIntent);
break;
case R.id.colors:
Intent colorsIntent = new Intent(MainActivity.this,NumbersActivity.class);
startActivity(colorsIntent);
break;
case R.id.family:
Intent familyIntent = new Intent(MainActivity.this,NumbersActivity.class);
startActivity(familyIntent);
break;
case R.id.phrases:
Intent phrasesIntent = new Intent(MainActivity.this,NumbersActivity.class);
startActivity(phrasesIntent);
break;
}
}
}
第二次更新：当我将MainActivity.java更改为此时，一切都可以正常运行]
/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.miwok;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set the content of the activity to use the activity_main.xml layout file
setContentView(R.layout.activity_main);
// Find the View that shows the numbers category
TextView numbers = (TextView) findViewById(R.id.numbers);
// Set a click listener on that View
numbers.setOnClickListener(new OnClickListener() {
// The code in this method will be executed when the numbers category is clicked on.
@Override
public void onClick(View view) {
// Create a new intent to open the {@link NumbersActivity}
Intent numbersIntent = new Intent(MainActivity.this, NumbersActivity.class);
// Start the new activity
startActivity(numbersIntent);
}
});
// Find the View that shows the family category
TextView family = (TextView) findViewById(R.id.family);
// Set a click listener on that View
family.setOnClickListener(new OnClickListener() {
// The code in this method will be executed when the family category is clicked on.
@Override
public void onClick(View view) {
// Create a new intent to open the {@link FamilyActivity}
Intent familyIntent = new Intent(MainActivity.this, FamilyActivity.class);
// Start the new activity
startActivity(familyIntent);
}
});
// Find the View that shows the colors category
TextView colors = (TextView) findViewById(R.id.colors);
// Set a click listener on that View
colors.setOnClickListener(new OnClickListener() {
// The code in this method will be executed when the colors category is clicked on.
@Override
public void onClick(View view) {
// Create a new intent to open the {@link ColorsActivity}
Intent colorsIntent = new Intent(MainActivity.this, ColorsActivity.class);
// Start the new activity
startActivity(colorsIntent);
}
});
// Find the View that shows the phrases category
TextView phrases = (TextView) findViewById(R.id.phrases);
// Set a click listener on that View
phrases.setOnClickListener(new OnClickListener() {
// The code in this method will be executed when the phrases category is clicked on.
@Override
public void onClick(View view) {
// Create a new intent to open the {@link PhrasesActivity}
Intent phrasesIntent = new Intent(MainActivity.this, PhrasesActivity.class);
// Start the new activity
startActivity(phrasesIntent);
}
});
}
}
whats the point?
您可以使用代码命名：通过
actionbar.setTitle（“标题在这里”）;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (!MyApplication.getInstance().isTablet())
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
setContentView(R.layout.activity_settings);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle(getString(R.string.settings));
....
}
因此，当我从课程示例中复制MainActivity.java时，所有标题都开始正常工作。区别在于，我使用了“ switch（view.getId（））”，而不是为每个活动创建新的onClick。我仍然不明白为什么它不起作用，但是希望我会从更多的经验中学到它。摘要：使用“ switch”语句进行活动可能会导致儿童活动标题出现问题（对于像我这样不了解的人）。