Java 在应用程序运行时每秒更新一次TextView
我是Android编程新手,但我对Java非常熟悉,所以 在这个应用程序中,我需要创建一个死亡/出生计数器和总人口计数器,因此我需要每秒更新活动中的字符串,但我无法找到任何解决方案 这是我的主要活动:Java 在应用程序运行时每秒更新一次TextView,java,android,Java,Android,我是Android编程新手,但我对Java非常熟悉,所以 在这个应用程序中,我需要创建一个死亡/出生计数器和总人口计数器,因此我需要每秒更新活动中的字符串,但我无法找到任何解决方案 这是我的主要活动: public class MainActivity extends ActionBarActivity { static int nasc; static int mortes; static int popTotal; @Override protec
public class MainActivity extends ActionBarActivity {
static int nasc;
static int mortes;
static int popTotal;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
nasc = 0;
mortes = 0;
popTotal = 0;
setContentView(R.layout.activity_main);
final TextView view = new TextView(this);
Boolean menu = false;
Handler handler = new Handler();
while (menu == false) {
handler.postDelayed(new Runnable() {
public void run() {
view.setText("Births : " + getNasc() + ".");
view.append("\n");
view.append("Deaths : " + getMortes() + ".");
view.append("\n");
view.append("Total Population : " + getPopTotal() + ".");
setContentView(view);
}
}, 1000);
}
}
private int getPopTotal() {
popTotal = nasc - mortes;
return popTotal;
}
private int getMortes() {
mortes = (int) (mortes + 1.7);
return mortes;
}
private int getNasc() {
nasc = nasc + 3;
return nasc;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.textView) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
我做错了什么?试试这个:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
nasc = 0;
mortes = 0;
popTotal = 0;
setContentView(R.layout.activity_main);
final TextView view = (TextView)findViewById(R.id.textView_id);
String allText="";
Boolean menu = false;
Handler handler = new Handler();
while (menu == false) {
handler.postDelayed(new Runnable() {
public void run() {
allText+="Births : " + getNasc() + ".";
allText+="\n";
allText+="Deaths : " + getMortes() + ".";
allText+="\n";
allTExt+="Total Population : " + getPopTotal() + ".";
view.setText(allText);
allText="";//reset the string
}
}, 1000);
}
}`
在您的activity_main.xml中,在您的文本视图声明中添加
<TextView ...
... <!--other params that you have set-->
android:id="@+id/textview_id"
... />
您需要做的是删除while循环,并在用新总数更新UI后,每秒重新运行Runnable if菜单==false
我只是让Runnable成为一个成员变量,而不是一个匿名类,使用StringBuilder为TextView构建文本,然后在每次运行完成时,如果菜单
仍然为false,则重新运行Runnable,从而使这个实现正常工作
public class MainActivity extends ActionBarActivity {
static int nasc;
static int mortes;
static int popTotal;
TextView view;
Handler handler;
Boolean menu;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
nasc = 0;
mortes = 0;
popTotal = 0;
view = (TextView) findViewById(R.id.text);
menu = false;
handler = new Handler();
handler.postDelayed(updateText, 1000);
}
public Runnable updateText = new Runnable() {
@Override
public void run() {
StringBuilder sb = new StringBuilder();
sb.append("Births : " + getNasc() + ".");
sb.append("\n");
sb.append("Deaths : " + getMortes() + ".");
sb.append("\n");
sb.append("Total Population : " + getPopTotal() + ".");
view.setText(sb.toString());
if (menu == false){
handler.postDelayed(this, 1000);
}
}
};
//.................
activity_main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
<TextView android:id="@+id/text" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
导入此:
//
导入java.util.concurrent.Executors;
导入java.util.concurrent.ScheduledExecutorService;
//
每一分钟使用一次:
ScheduledExecutorService scheduleTaskExecut = Executors.newScheduledThreadPool(5);
// This run every one minute
scheduleTaskExecut.scheduleAtFixedRate(new Runnable() {
public void run() {
//in this Methos Update Your Text as You Need
UpdateYourText();
}
}, 0, 1, TimeUnit.MINUTES);
试着用这种方法让我帮你
public class test extends Activity {
private TextView textView;
private int i = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.test);
textView = (TextView)findViewById(R.id.text);
set();
}
private void set(){
final String text ="A n d r o i d P r o g r a m m i n g";
final String[] words = text.toString().split(" ");
final Handler handler = new Handler();
handler.post(new Runnable(){
@Override
public void run() {
textView.setText(""+words[i]);
i++;
if(i < words.length) {
handler.postDelayed(this, 1000);
}
}
});
}}
公共类测试扩展活动{
私有文本视图文本视图;
私有整数i=0;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.test);
textView=(textView)findViewById(R.id.text);
set();
}
私有空集(){
最终字符串text=“A n d r o i d P r o g r A m i n g”;
最后一个字符串[]单词=text.toString().split(“”);
最终处理程序=新处理程序();
handler.post(新的Runnable(){
@凌驾
公开募捐{
textView.setText(“+words[i]);
i++;
如果(i
在活动主视图中添加文本视图,并在中更新,而不是每次更新setContentView。第二点:使用一个本地字符串并用您的数据更新该字符串,然后按该字符串设置文本,这样对我来说更好。让我们试试看,嗯,我认为在onCreate()
中加入while循环会阻止活动生命周期回调的正确执行,因为在菜单
等于true之前,它永远不会进入onResume()
中。谢谢,我们可以为您安排下面给出的ExecutorService答案并更新其中的textview,我的主要错误是使用While循环?