Android 更新UI _android

智者不为愚者谋，勇者不为怯者死。这篇文章主要讲述Android 更新UI相关的知识，希望能为你提供帮助。
本篇简单android里面更新UI的四种方法。
更新UI简介Android 更新UI主要是主线程进行更新,即UI线程更新。如果在主线程外更新则会报错。

android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

只有创建这个视图层次的线程才能修改它的视图

Handler消息传递

package com.example.chenjy.chenjy; import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.widget.TextView; public class MainActivity extends Activity {private TextView tv_token; Handler handler = new Handler() { public void handleMessage(Message msg) { if(msg.what==0x12) { tv_token.setText("update UI"); } }; }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); new MyThread().start(); }public void initView(){tv_token = (TextView)findViewById(R.id.tv_token); }class MyThread extends Thread { @Override public void run() { //延迟两秒更新 try { Thread.sleep(2000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } handler.sendEmptyMessage(0x12); } } }

使用runOnUiThread

package com.example.chenjy.chenjy; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class MainActivity extends Activity {private TextView tv_token; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); new MyThread().start(); }public void initView(){tv_token = (TextView)findViewById(R.id.tv_token); }class MyThread extends Thread { @Override public void run() { runOnUiThread(new Runnable() {@Override public void run() { // TODO Auto-generated method stub try { //延迟两秒更新 Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } tv_token.setText("update UI"); } }); } } }

Handler 的post(Runnable runnable)

package com.example.chenjy.chenjy; import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.widget.TextView; public class MainActivity extends Activity {private TextView tv_token; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tv_token = (TextView) findViewById(R.id.tv_token); Handler handler = new Handler(); handler.post(new Runnable() { @Override public void run() { try { //延迟两秒更新 Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } tv_token.setText("update UI"); }}); }}

AsyncTask异步任务

package com.example.chenjy.chenjy; import android.app.Activity; import android.os.AsyncTask; import android.os.Bundle; import android.widget.TextView; public class MainActivity extends Activity {private TextView tv_token; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tv_token = (TextView) findViewById(R.id.tv_token); new UpdateUI().execute(); }class UpdateUI extends AsyncTask< String, String, String> {@Override protected String doInBackground(String... params) { try { Thread.sleep(2000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } @Override protected void onPostExecute(String result) { // TODO Auto-generated method stub tv_token.setText("update UI"); }} }

【Android 更新UI】