簡單。生活。享受

●實作練習：預期畫面 

        

 

●程式說明：

(一)Radion button屬性

=>buttonTint:選鈕顏色

=>textcolor:文字顏色

=>checked:是否被選

●實作練習：xml

(一)activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.student.lab04.MainActivity">

    <TextView
        android:id="@+id/initext"
        android:layout_width="250dp"
        android:layout_height="250dp"
        android:layout_gravity="center"
        android:layout_marginTop="30dp"
        android:gravity="center"
        android:text="顏色未設定"
        android:textSize="25sp"
        android:textColor="@android:color/background_dark"/>

    <Button
        android:id="@+id/gotopick"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="30dp"
        android:textSize="16sp"
        android:text="選擇顏色"
        android:onClick="gotopick"/>

</LinearLayout>

 

(二)activity_color.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingTop="130dp"
    tools:context="com.example.student.lab04.colorPick">

    <RadioGroup
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center">
        <!--預設紅色被選取-->
        <RadioButton
            android:id="@+id/red"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="12dp"
            android:buttonTint="@android:color/holo_red_light"
            android:checked="true"
            android:onClick="picked"
            android:text="holo_red_light"
            android:textColor="@android:color/holo_red_light"
            android:textSize="20sp" />

        <RadioButton
            android:id="@+id/orange"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="12dp"
            android:buttonTint="@android:color/holo_orange_dark"
            android:onClick="picked"
            android:text="holo_orange_dark"
            android:textColor="@android:color/holo_orange_dark"
            android:textSize="20sp" />

        <RadioButton
            android:id="@+id/green"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="12dp"
            android:buttonTint="@android:color/holo_green_light"
            android:onClick="picked"
            android:text="holo_green_light"
            android:textColor="@android:color/holo_green_light"
            android:textSize="20sp" />

        <RadioButton
            android:id="@+id/blue"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="12dp"
            android:buttonTint="@android:color/holo_blue_dark"
            android:onClick="picked"
            android:text="holo_blue_dark"
            android:textColor="@android:color/holo_blue_dark"
            android:textSize="20sp" />

    </RadioGroup>

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:orientation="horizontal">

        <Button
            android:id="@+id/cancel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="cancel"
            android:text="CANCEL" />

        <Button
            android:id="@+id/ok"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="ok"
            android:text="OK" />
    </LinearLayout>

</LinearLayout>

 

●實作練習：Java Code

(一)MainActivity.java

public class MainActivity extends AppCompatActivity {
    Button gotopick;
    //因為有另一個class要取得color和text的值，
    //並且設定initext，所以這三個都要是static
    static TextView initext;
    static int color=0;
    static CharSequence text="";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        gotopick =(Button)findViewById(R.id.gotopick);
        initext =(TextView)findViewById(R.id.initext);
    }

    public void gotopick(View view){
        Intent in=new Intent();
        //可以用this取代MainAcitvity.this
        in.setClass(this,colorPick.class);
        startActivity(in);
    }
}

 

(二)colorPick.java

public class colorPick extends AppCompatActivity {
    Button cancel,ok;
    RadioButton red,orange,green,blue;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_color_pick);
        cancel =(Button)findViewById(R.id.cancel);
        ok =(Button)findViewById(R.id.ok);
        red =(RadioButton)findViewById(R.id.red);
        green =(RadioButton)findViewById(R.id.green);
        orange =(RadioButton)findViewById(R.id.orange);
        blue =(RadioButton)findViewById(R.id.blue);
    }
    public void picked(View view){
        if(red.isChecked()){
            //取得radio button的文字顏色丟給color
            //(因為是屬於MainAcitvity的，所以要用MainActivity.color)
            MainActivity.color=red.getCurrentTextColor();
            //取得radio button的文字丟給text
            MainActivity.text=red.getText();
            //設定initext這個textview的背景顏色
            MainActivity.initext.setBackgroundColor(MainActivity.color);
            //設定initext這個textview的文字
            MainActivity.initext.setText(MainActivity.text);
            //顏色表示方式：0xAARRGGBB(AA代表透明度alpha，不透明為ff)
            MainActivity.initext.setTextColor(0xffffffff);
        }
        if(orange.isChecked()){
            MainActivity.color=orange.getCurrentTextColor();
            MainActivity.text=orange.getText();
            MainActivity.initext.setBackgroundColor(MainActivity.color);
            MainActivity.initext.setText(MainActivity.text);
            MainActivity.initext.setTextColor(0xffffffff);
        }
        if(green.isChecked()){
            MainActivity.color=green.getCurrentTextColor();
            MainActivity.text=green.getText();
            MainActivity.initext.setBackgroundColor(MainActivity.color);
            MainActivity.initext.setText(MainActivity.text);
            MainActivity.initext.setTextColor(0xffffffff);
        }
        if(blue.isChecked()){
            MainActivity.color=blue.getCurrentTextColor();
            MainActivity.text=blue.getText();
            MainActivity.initext.setBackgroundColor(MainActivity.color);
            MainActivity.initext.setText(MainActivity.text);
            MainActivity.initext.setTextColor(0xffffffff);
        }

    }
    public void cancel(View view){
        //setChecked:Changes the checked state of this button
        //所以恢復到紅色被選擇的狀態
        red.setChecked(true);
    }

    public void ok(View view){
        picked(view);
        //Call this when your activity is done and should be closed
        finish();
    }
}

 

 

 

*程式參考(gitHub)：RadioButton與跨activity傳送資料實作練習