java - 我使用 Onclick 按钮事件来更改颜色，但当应用程序进入横向模式时，它会丢失颜色。该怎么办？

Question

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
     android:background="@android:color/background_light"
           >


<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="45dp"
    android:layout_alignParentTop="true"
    android:layout_marginTop="31dp"
    android:text="What do u Think about the Android?"
    android:textSize="20dp" />

<Button
    android:id="@+id/btn01"
    android:layout_width="156dp"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/textView1"
    android:layout_alignRight="@+id/textView1"
    android:layout_below="@+id/textView1"
    android:layout_marginTop="31dp"
    android:text="Site" />

<Button
    android:id="@+id/btn02"
    android:layout_width="156dp"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/btn01"
    android:layout_alignRight="@+id/btn01"
    android:layout_below="@+id/btn01"
    android:layout_marginTop="25dp"
    android:text="Mobile" />

<Button
    android:id="@+id/btn03"
    android:layout_width="156dp"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/btn02"
    android:layout_alignRight="@+id/btn02"
    android:layout_below="@+id/btn02"
    android:layout_marginTop="25dp"
    android:text="Os" />

<Button
    android:id="@+id/btn04"
    android:layout_width="156dp"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/btn03"
    android:layout_alignRight="@+id/btn03"
    android:layout_below="@+id/btn03"
    android:layout_marginTop="25dp"
    android:text="Environment" />

</RelativeLayout>

我的 Xml 文件有四个按钮和一个 TextView

private Button btn1 ,btn2,btn3,btn4;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.mains);


 btn1 = (Button) findViewById(R.id.btn01);
  btn2 = (Button)findViewById(R.id.btn02);        
 btn3 = (Button)findViewById(R.id.btn03);
 btn4 = (Button) findViewById(R.id.btn04);


 btn1.setOnClickListener(this);
  btn2.setOnClickListener(this);
  btn3.setOnClickListener(this);
  btn4.setOnClickListener(this);

}
  @Override
    public void onClick(View v) {       
        if(v.getId() == R.id.btn01) {
                btn1.setBackgroundColor(Color.RED);
                btn1.setTextColor(Color.WHITE);

            }
        if(v.getId() == R.id.btn02) {

                btn2.setBackgroundColor(Color.RED);
                btn2.setTextColor(Color.WHITE);

        }
        if(v.getId() == R.id.btn03) {
                btn3.setBackgroundColor(Color.GREEN);
                btn3.setTextColor(Color.WHITE);

        }

        if(v.getId() == R.id.btn04) {

                btn4.setBackgroundColor(Color.RED);
                btn4.setTextColor(Color.WHITE);
            }

  }

  }

包含按钮颜色所有代码的java文件。

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

<uses-sdk
    android:minSdkVersion="14"
    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.mynew.MainActivity"
        android:configChanges="orientation"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>

    </activity>

</application>

list 包含想要的一切。请帮我解决这个问题。该应用程序在纵向模式下工作正常，但所选按钮在横向模式下失去颜色

Answer 1

您可以将 android:freezesText="true" 设置为您的按钮。或者，您可以在 onSaveInstanceState() 中手动保存每个按钮的状态，然后当您在 onCreate() 或 onRestoreInstanceState() 回调中获取该值时。

例如(假设您只有两个按钮):

private boolean btn1Pressed = false;
private boolean btn2Pressed = false;

static final String STATE_BUTTON1 = "button_1";
static final String STATE_BUTTON2 = "button_2";

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    // Save the buttons current state
    savedInstanceState.putBoolean(STATE_BUTTON1, btn1Pressed);
    savedInstanceState.putBoolean(STATE_BUTTON2, btn2Pressed);

    super.onSaveInstanceState(savedInstanceState);
}

以及来自 onCreate() 或 onRestoreInstanceState() :

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.mains);

    if (savedInstanceState != null) {
        // Restore states of buttons from saved state
        btn1Pressed = savedInstanceState.getBoolean(STATE_BUTTON1, false);
        btn2Pressed = savedInstanceState.getBoolean(STATE_BUTTON2, false);            
    }

    btn1 = (Button)findViewById(R.id.btn01);
    btn1.setOnClickListener(this);
    btn2 = (Button)findViewById(R.id.btn02);
    btn2.setOnClickListener(this);

    if(btn1Pressed){
        changeColor(btn1);
    }

   if(btn2Pressed){
        changeColor(btn2);
    }    
}

private void changeColor(Button b){
    b.setBackgroundColor(Color.RED);
    b.setTextColor(Color.WHITE);
}

此外，在您的 onClick() 方法中，如果按下按钮，您需要设置新状态。例如:

if(v.getId() == R.id.btn01) {
    btn1Pressed = true;
    changeColor((Button)v);
}
// do the same with other buttons...