[移动开发]Handler通信（五）

使用Handler实现打地鼠（下）。

该说不说，上代码！

首先给地鼠一个位置：

int position= msg.arg1;
                    activity.mDiglettImageView.setX(activity.mPosition[position][0]);
                    activity.mDiglettImageView.setY(activity.mPosition[position][1]);
                    activity.mDiglettImageView.setVisibility(View.VISIBLE);

                    int randomTime=new Random().nextInt(500)+500;//随机从0-500之间取一个数

                    activity.next(randomTime);
                    break;

然后在next里面写方法，延时、自加：

int position=new Random().nextInt(mPosition.length);

        Message message=Message.obtain();
        message.what=123;
        message.arg1=position;

        mHandler.sendMessageDelayed(message,delayTime);
        mTotalCount++;

start方法：

 //发送消息 handlers sendmessagedelayer
        mResultTextView.setText("开始啦");
        mStarButton.setText("游戏中...");
        mStarButton.setEnabled(false);
        next(0);

如果打到，接停止：

@Override
    public boolean onTouch(View v, MotionEvent event) {
        v.setVisibility(View.GONE);
        mSuccessCount++;
        mResultTextView.setText("打到了"+mSuccessCount+"只，共"+Max_count+"只.");
        return false;
    }

最后数据清零：

 private void clear() {
        mTotalCount=0;
        mSuccessCount=0;
        mDiglettImageView.setVisibility(View.GONE);
        mStarButton.setText("点击开始");
        mStarButton.setEnabled(true);
    }

完整的代码如下：

package com.example.handlerproject;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import java.lang.ref.WeakReference;
import java.util.Random;

public class DiglettActivity extends AppCompatActivity implements View.OnClickListener ,View.OnTouchListener{

    private TextView mResultTextView;
    private ImageView mDiglettImageView;
    private Button mStarButton;

    //坐标用二维数组表示
    public int[][] mPosition=new int[][]{
            {342,180},{432,880},
            {354,215},{456,741},
            {258,180},{147,880},
            {126,456},{159,426}
    };

    private int mTotalCount;
    private int mSuccessCount;

    public static final int Max_count=10;

    private DiglettHandler mHandler=new DiglettHandler(this);


    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.diglettactivity);
        //初始化控件
        initView();
    }

    private void initView() {
        mResultTextView = findViewById(R.id.text_View);
        mDiglettImageView = findViewById(R.id.image_View);
        mStarButton = findViewById(R.id.button);

        mStarButton.setOnClickListener(this);
        mDiglettImageView.setOnTouchListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.button:
                start();
                break;
        }
    }

    private void start() {
        //发送消息 handlers sendmessagedelayer
        mResultTextView.setText("开始啦");
        mStarButton.setText("游戏中...");
        mStarButton.setEnabled(false);
        next(0);

    }
    public void next(int delayTime){
        int position=new Random().nextInt(mPosition.length);

        Message message=Message.obtain();
        message.what=123;
        message.arg1=position;

        mHandler.sendMessageDelayed(message,delayTime);
        mTotalCount++;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        v.setVisibility(View.GONE);
        mSuccessCount++;
        mResultTextView.setText("打到了"+mSuccessCount+"只，共"+Max_count+"只.");
        return false;
    }

    //做一个handler，实现handlers，不然会引起内存泄露
    public static class DiglettHandler extends Handler{
        public final WeakReference<DiglettActivity> mWeakReference;

        public DiglettHandler(DiglettActivity activity) {
            this.mWeakReference = new WeakReference<>(activity);
        }

        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            DiglettActivity activity=mWeakReference.get();

            switch (msg.what){
                case 123:
                    if (activity.mTotalCount>Max_count){
                        activity.clear();
                        Toast.makeText(activity, "地鼠打完了", Toast.LENGTH_SHORT).show();
                        return;
                    }
                    int position= msg.arg1;
                    activity.mDiglettImageView.setX(activity.mPosition[position][0]);
                    activity.mDiglettImageView.setY(activity.mPosition[position][1]);
                    activity.mDiglettImageView.setVisibility(View.VISIBLE);

                    int randomTime=new Random().nextInt(500)+500;//随机从0-500之间取一个数

                    activity.next(randomTime);
                    break;
            }
        }
    }

    private void clear() {
        mTotalCount=0;
        mSuccessCount=0;
        mDiglettImageView.setVisibility(View.GONE);
        mStarButton.setText("点击开始");
        mStarButton.setEnabled(true);
    }
}