大家都知道直接在子线程里更新UI是不被允许的,所以下面提供两种方法解决问题:
直接上代码:
- package com.wr.updateui;
- import android.annotation.SuppressLint;
- import android.app.Activity;
- import android.os.Bundle;
- import android.os.Handler;
- import android.os.Message;
- import android.view.Menu;
- import android.view.MenuItem;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.widget.Button;
- import android.widget.TextView;
- public class MainActivity extends Activity {
- private static final int UPDATE_TEXT = 1;
- private TextView tv;
- private Button btn;
- @SuppressLint("HandlerLeak")
- private Handler handler = new Handler() {
- public void handleMessage(Message msg) {
- switch (msg.what) {
- case UPDATE_TEXT:
- tv.setText("nihao");
- default:
- break;
- }
- }
- };
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- tv = (TextView) findViewById(R.id.textView);
- btn = (Button) findViewById(R.id.button);
- btn.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View arg0) {
- // TODO Auto-generated method stub
- /**
- * 第一种使用Android的异步处理机制。
- */
- /*
- new Thread(new Runnable() {
- @Override
- public void run() {
- // TODO Auto-generated method stub
- Message message = new Message();
- message.what = UPDATE_TEXT;
- handler.sendMessage(message);
- }
- }).start();
- */
- /**
- * 第二种,直接使用runOnUiThread.
- */
- runOnUiThread(new Runnable() {
- @Override
- public void run() {
- // TODO Auto-generated method stub
- tv.setText("nihao");
- }
- });
- }
- });
- }
- @Override
- public boolean onCreateOptionsMenu(Menu menu) {
- // Inflate the menu; this adds items to the action bar if it is present.
- getMenuInflater().inflate(R.menu.main, menu);
- return true;
- }
- @Override
- public boolean onOptionsItemSelected(MenuItem item) {
- // Handle action bar item clicks here. The action bar will
- // automatically handle clicks on the Home/Up button, so long
- // as you specify a parent activity in AndroidManifest.xml.
- int id = item.getItemId();
- if (id == R.id.action_settings) {
- return true;
- }
- return super.onOptionsItemSelected(item);
- }
- }
来源: http://www.phpxs.com/code/1002623/