接口

implements后，就会直接调用里面的方法，或重写再使用。
例子：

public interface IView {
    /**
     * Gets input string.
     *得到数据
     * @return the input string
     */
    String getInputString();

    /**
     * Sets result string.
     *输出数据
     * @param string the string
     */
    void setResultString(String string);
}

package com.example.administrator.chart1212;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import com.example.common.Common;
import com.example.common.app.Activity;

import butterknife.BindView;
import butterknife.OnClick;

public class MainActivity extends Activity implements IView{
    @BindView( R.id.txt_result )
    TextView mResultText;
    @BindView( R.id.edit_query )
    EditText mInputText;
    private IPresenter mPresenter;
    @Override
    protected int getContentLayouId() {
        return R.layout.activity_main2;
    }

    @Override
    protected void initData() {
        super.initData();
        mPresenter =new Presenter( this );
    }

    @OnClick(R.id.btn_submit)
    void onSubmit(){
        mPresenter.search();
    }

    @Override
    public String getInputString() {
        return mInputText.getText().toString();
    }

    @Override
    public void setResultString(String string) {
        mResultText.setText( string );
    }
}