textView = (TextView) findViewById( R.id.tv );
new Thread(new Runnable() {
@Override
public void run() {
runOnUiThread(new Runnable() {
@Override
public void run() {
textView.setText( "更新UI了");
}
});
}
}).start();

android Activity runOnUiThread() 方法使用

2、Handler sendEmptyMessage()

package lib.com.myapplication;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
private TextView textView ;
Handler handler = new Handler( ) {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
textView.setText( "Ui更新了");
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById( R.id.tv );
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep( 2000 );
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.sendEmptyMessage( 2 ) ;
}
}).start();
}
}

3、Handler post()

package lib.com.myapplication;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
private TextView textView ;
Handler handler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById( R.id.tv );
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep( 2000 );
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.post(new Runnable() {
@Override
public void run() {
textView.setText( "Ui更新了");
}
}) ;
}
}).start();
}
}

4、view Post()　

textView = (TextView) findViewById( R.id.tv );
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep( 2000 );
} catch (InterruptedException e) {
e.printStackTrace();
}
textView.post(new Runnable() {
@Override
public void run() {
textView.setText( "Ui更新了");
}
}) ;
}
}).start();

總結(jié)：

1、其實(shí)上面的四種方式都可歸結(jié)于一種方式：handler 用于Android線程之間的通信。

2、為什么android要求只能在UI線程進(jìn)行UI操作？主要還是為了避免多線程造成的并發(fā)的問題。在單線程操作UI是安全的。

以上所述是給大家介紹的Android 更新UI的方法匯總的相關(guān)知識(shí)，希望對(duì)大家有所幫助，如果大家有疑問歡迎給我留言，小編會(huì)及時(shí)回復(fù)大家的！

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