package me.yoqi.deleteallcontacts; import java.util.ArrayList; import java.util.HashMap; import android.content.Context; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.TextView; import android.widget.Toast; import me.yoqi.deleteallcontacts.utils.ContactManager; public class MainActivity extends AppCompatActivity { Button btnDelUser; TextView tvContact; Context mContext; static String TAG = "me.yoqi.deleteallcontacts.MainActivity"; ContactManager contactManager; private static class MyHandler extends Handler { public MyHandler(Context mContext) { } @Override public void handleMessage(Message msg) { super.handleMessage(msg); switch (msg.what) { case 0: // 更新UI break; } super.handleMessage(msg); } } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mContext = this; contactManager = new ContactManager(mContext); initView(); initData(); } void initView() { btnDelUser = (Button) findViewById(R.id.btn_del_contact); tvContact = (TextView) findViewById(R.id.tv_contact); btnDelUser.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { HashMap contactNum = contactManager.delAllContacts(); Toast.makeText(mContext, "已经删除 " + contactNum.size() + " 个联系人", Toast.LENGTH_SHORT).show(); initData(); } }); } void initData() { MyHandler mHandler = new MyHandler(this); ArrayList allContact = contactManager.getAllContact(); tvContact.setText(allContact.toString()); } }