Button組實現文字顏色變化

要求

建立一個Button數組，實現一個顏色選擇器。

MainActivity

package com.example.hades.demo2;

import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import static android.R.attr.button;

public class MainActivity extends AppCompatActivity {
    EditText et;
    TextView tv;
    Integer []bts = {R.id.button_0,R.id.button_1,R.id.button_2,R.id.button_3,R.id.button_4,R.id.button_5};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.textView);
        et = (EditText) findViewById(R.id.editText);
        et.addTextChangedListener(new changeText());
        for(int i=0;i<6;i++){
            new button_click(bts[i]);
        }

    }
    private class button_click{
        button_click(Integer id){
            Button bt;
            bt =(Button)findViewById(id);
            Drawable background = bt.getBackground();
            ColorDrawable colorDrawable = (ColorDrawable) background;
            int color = colorDrawable.getColor();
            bt.setOnClickListener(new click(color));
        }
    }
    private class changeText implements TextWatcher {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            tv.setText(s);
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            tv.setText(s);
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    }

    private class click implements View.OnClickListener {
        int bt_color;
        click(int color){
            bt_color = color;
        }
        public void onClick(View v) {
            tv.setTextColor(bt_color);
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context="com.example.hades.demo2.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:weightSum="1"
        tools:layout_editor_absoluteX="8dp"
        tools:layout_editor_absoluteY="7dp">

        <TextView
            android:id="@+id/textView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="0.04"
            android:fontFamily="sans-serif"
            android:text="Hello World"
            android:textAppearance="@style/TextAppearance.AppCompat"
            android:textSize="30sp"
            android:typeface="normal" />

        <EditText
            android:id="@+id/editText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ems="10"
            android:inputType="textPersonName"
            android:text="Hello World" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="0.04"
            android:orientation="horizontal"
            tools:layout_editor_absoluteX="8dp"
            tools:layout_editor_absoluteY="116dp">

            <Button
                android:id="@+id/button_0"
                android:layout_width="35dp"
                android:layout_height="40dp"
                android:background="@android:color/black"
                android:layout_weight="1" />

            <Button
                android:id="@+id/button_1"
                android:layout_width="35dp"
                android:layout_height="40dp"
                android:layout_weight="1"
                android:background="@android:color/holo_red_dark" />

            <Button
                android:id="@+id/button_2"
                android:layout_width="35dp"
                android:layout_height="40dp"
                android:layout_weight="1"
                android:background="@android:color/holo_green_dark" />

            <Button
                android:id="@+id/button_3"
                android:layout_width="35dp"
                android:layout_height="40dp"
                android:layout_weight="1"
                android:background="@android:color/holo_blue_bright" />

            <Button
                android:id="@+id/button_4"
                android:layout_width="35dp"
                android:layout_height="40dp"
                android:layout_weight="1"
                android:background="@android:color/holo_orange_dark" />
            <Button
                android:id="@+id/button_5"
                android:layout_width="35dp"
                android:layout_height="40dp"
                android:layout_weight="1"
                android:background="@android:color/holo_blue_light" />
        </LinearLayout>

    </LinearLayout>

</android.support.constraint.ConstraintLayout>