置换文字颜色的机关

Button与TextView的交互

package com.wzc.ex03_12;

import android.content.DialogInterface;
import android.graphics.Color;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private Button buOpen;
    private TextView mText;
    private int[] mColors;
    private int colornum;


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

        buOpen= (Button) findViewById(R.id.bt_open);
        mText = (TextView) findViewById(R.id.tv_1);

        mColors = new int[]{
                Color.BLACK,Color.RED,Color.BLUE,
                Color.GREEN,Color.MAGENTA,Color.YELLOW,
                ContextCompat.getColor(this,R.color.opaque_red),
                ContextCompat.getColor(this,R.color.translucent_red) };
        colornum = 0;
        buOpen.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(colornum<mColors.length){
                    mText.setTextColor(mColors[colornum]);
                    colornum++;
                }
                else
                    colornum=0;
            }
        });
    }
}