實現購物車那種加減效果，實現購物車

實現購物車那種加減效果，實現購物車

public class MainActivity extends AppCompatActivity {private ImageView img1, img2;private TextView tv1;private int mNumber = 0;private int mMaxNumber = 99;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);img1 = (ImageView) findViewById(R.id.iv1);img2 = (ImageView) findViewById(R.id.iv2);tv1 = (TextView) findViewById(R.id.tv);img1.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (mNumber > 0) {mNumber--;}setNumberText(mNumber + "");}});img2.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (mNumber < mMaxNumber) {mNumber++;}setNumberText(mNumber + "");}});}private void setNumberText(String s) {tv1.setText(s);mNumber = Integer.valueOf(s);if (mAddAndSubtractOnClickListener != null) {mAddAndSubtractOnClickListener.numberChange(mNumber);}}private AddAndSubtractOnClickListener mAddAndSubtractOnClickListener;public void setAddAndSubtractOnClickListener(AddAndSubtractOnClickListener addAndSubtractOnClickListener) {mAddAndSubtractOnClickListener = addAndSubtractOnClickListener;}/*** 加減按鈕回調介面*/public interface AddAndSubtractOnClickListener {void numberChange(int num);}}