public class MainActivity extends AppCompatActivity { private ImageView img1, img2; private TextView tv1; private int mNumber = 0; private int mMaxNumber = 99; @Override protected 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() { @Override public void onClick(View v) { if (mNumber > 0) { mNumber--; } setNumberText(mNumber + ""); } }); img2.setOnClickListener(new View.OnClickListener() { @Override public 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; } /** * 加减按钮回调接口 */ public interface AddAndSubtractOnClickListener { void numberChange(int num); } }