Android 更新UI的方法汇总

1、activity的 runonuithread

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();

总结：

1、其实上面的四种方式都可归结于一种方式：handler 用于android线程之间的通信。

2、为什么android要求只能在ui线程进行ui操作？ 主要还是为了避免多线程造成的并发的问题。在单线程操作ui是安全的。

以上所述是 给大家介绍的android 更新ui的方法汇总的相关知识，希望对大家有所帮助，如果大家有疑问欢迎给我留言，小编会及时回复大家的！