Android 开发笔记___textview_聊天室效果

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/tv_control"
        android:layout_marginTop="20dp"
        android:gravity="center"
        android:text="聊天室效果，点击添加聊天记录，长按删除聊天记录"
        />

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="200dp">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/tv_bbs"
            android:layout_marginTop="20dp"
            android:scrollbars="vertical"
            android:textColor="@color/text_color"
            android:textSize="17sp"/>

    </LinearLayout>

</LinearLayout>

java

package com.example.alimjan.hello_world;

import android.app.Activity;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.text.format.DateUtils;
import android.text.method.ScrollingMovementMethod;
import android.view.Gravity;
import android.view.View;
import android.widget.TextView;

/**
 * Created by alimjan on 6/30/2017.
 */

public class class__2_3_1_2 extends AppCompatActivity implements DialogInterface.OnClickListener,View.OnLongClickListener, View.OnClickListener {

    private TextView tv_bbs,tv_control;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.code_2_3_1_2);

        tv_control = (TextView) findViewById(R.id.tv_control);
        tv_control.setOnClickListener(this);
        tv_control.setOnLongClickListener(this);
        tv_bbs = (TextView) findViewById(R.id.tv_bbs);
        tv_bbs.setOnClickListener(this);
        tv_bbs.setOnLongClickListener(this);
        tv_bbs.setGravity(Gravity.LEFT|Gravity.BOTTOM);
        tv_bbs.setLines(8);
        tv_bbs.setMaxLines(8);
        tv_bbs.setMovementMethod(new ScrollingMovementMethod());
    }

    private String[] mChatStr={"你吃饭了吗honey？","今天天气超级热！你们那儿呢？","我中奖啦！","走不走看电影~","你在干什么？"};

    public static void startHome(Context mContext) {
        Intent intent = new Intent(mContext, class__2_3_1_2.class);
        mContext.startActivity(intent);
    }

    @Override
    public void onClick(DialogInterface dialog, int which) {

    }

    @Override
    public boolean onLongClick(View v) {
        if(v.getId() == R.id.tv_control || v.getId() == R.id.tv_bbs){
            tv_bbs.setText("");
        }
        return true;
    }

    @Override
    public void onClick(View v) {
        if(v.getId() == R.id.tv_control || v.getId() == R.id.tv_bbs){
            int random = (int) ((Math.random()*10)%5);
            String newstr = String.format("%s
%s%s",tv_bbs.getText().toString(), DateUtil.getCurDateStr(),mChatStr[random]);
            tv_bbs.setText(newstr);
        }
    }
}