我想在Android中制作一个chronometer计时器，使用了timer和sheduleAtFixedRate 方法。看起来像是在timer的run方法中调用textview后，程序就会出错停止运行。我用的是以下的代码，哪里出错了呢？
Button boton_iniciar;
TextView texto_cronometro;
Timer count;
int a = 0;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cronometro);
/**********************/
boton_iniciar = (Button) findViewById(R.id.button1);
texto_cronometro = (TextView) findViewById(R.id.textView1);
count= new Timer("Contador");
boton_iniciar.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
count.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
// TODO Auto-generated method stub
a++;
texto_cronometro.setText(String.valueOf(a));
}
}, 100, 100);
}
});
}
所有要改变UI对象的的action都应该在主UI中运行。
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cronometro);
/**********************/
boton_iniciar = (Button) findViewById(R.id.button1);
texto_cronometro = (TextView) findViewById(R.id.textView1);
count= new Timer("Contador");
boton_iniciar.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
count.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
// TODO Auto-generated method stub
a++;
ActivityCronometro.this.runOnUiThread(new Runnable() {
@Override
public void run() {
texto_cronometro.setText(String.valueOf(a));
}
});
}
}, 100, 100);
}
});
}
要操作界面控件，必须在runnable中，你可以查一下
参考代码：
private Handler handler = new Handler( );
private Runnable runnable = new Runnable( ) {
public void run ( )
{
atextview.setText(String.valueOf(a));
handler.postDelayed(this,1000); //继续Timer,如果不继续，这句就不要
}
};
handler.postDelayed(runnable,1000); // 开始Timer
handler.removeCallbacks(runnable); //停止Timer
更新UI线程之外的用户界面。
用这些代码：
<youractivityname>.this.runOnUiThread(new Runnable() {
public void run() {
texto_cronometro.setText(String.valueOf(a));
}
});
代替
texto_cronometro.setText(String.valueOf(a));