android - 使用 Android LinearLayout 的问题

Question

我有一个 LinearLayout，包含一个 EditText 和一个 TextView。我的 ConsoleWindow 在循环中运行，我想在每次迭代中更新 TextView。

问题是我可能只初始化一次 EditText(否则它是不可访问的)而且 LinearLayout 可能只初始化一次(否则它会删除 编辑文本).

我不能将 LinearLayout 和 EditText 放在 if 语句中:

if (firstRun) {
     // initialize LinearLayout and EditText
     firstRun = false;
}
// TEXTVIEW
TextView tv = new TextView(getApplicationContext())
tv.setText(dataStringTot);
layout.addView(tv); // "Qualifier must be an Expression."

因为 IDE 在 layout.addView(tv); 返回:“Qualifier must be an expression.”

我的代码:

public class MainActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

getInetContent();
}

getInetContent() { // would be a thread
// getting data...

Bundle b = new Bundle();
b.putString("StringNMEA", NMEA);
Message m = mhandler.obtainMessage();
m.setData(b);
mhandler.sendMessage(m);
}


Handler handler = new Handler() {
    public void handleMessage(Message msg) {
        String dataString = "";
        Bundle bundle = msg.getData();

        if (bundle.containsKey("display")) {
        ConsoleWindow(dataString);
        }
    }
}

private void ConsoleWindow(String dataString) {

            // LINEAR LAYOUT
            LinearLayout layout = new LinearLayout(this);
            setContentView(layout);
            layout.setOrientation(LinearLayout.VERTICAL);
            layout.setBackgroundColor(Color.parseColor("#000000")); // black


            // EDITTEXT
            EditText et = new EditText(getApplicationContext());
            et.setHint("Enter Command");
            layout.addView(et);


            // TEXTVIEW
            TextView tv = new TextView(getApplicationContext());
            tv.setText(dataStringTot);
            layout.addView(tv);
            }
}

我的带有 if 语句的代码:

public boolean firstRun = true;

public class MainActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

getInetContent();
}

getInetContent() { // would be a thread
// getting data...

Bundle b = new Bundle();
b.putString("StringNMEA", NMEA);
Message m = mhandler.obtainMessage();
m.setData(b);
mhandler.sendMessage(m);
}


Handler handler = new Handler() {
    public void handleMessage(Message msg) {
        String dataString = "";
        Bundle bundle = msg.getData();

        if (bundle.containsKey("display")) {
        ConsoleWindow(dataString);
        }
    }
}

private void ConsoleWindow(String dataString) {
       if (firstRun) {
            // initialize LinearLayout and EditText:
            // LINEAR LAYOUT
            LinearLayout layout = new LinearLayout(this);
            setContentView(layout);
            layout.setOrientation(LinearLayout.VERTICAL);
            layout.setBackgroundColor(Color.parseColor("#000000")); // black


            // EDITTEXT
            EditText et = new EditText(getApplicationContext());
            et.setHint("Enter Command");
            layout.addView(et);
            firstRun = false;
        }


            // TEXTVIEW
            TextView tv = new TextView(getApplicationContext());
            tv.setText(dataStringTot);
            layout.addView(tv);
            }
}

我该如何解决这个问题？

Answer 1

我想你想在每次迭代时更新它们的颜色/文本。

您无需在每次要修改 View 时都创建一个新 View 。设置您的布局，获取 View ，然后将这些 View 传递到您的循环中。

LinearLayout layout = new LinearLayout(this);
EditText et = new EditText(this);
TextView tv = new TextView(this);
layout.addView(et);
layout.addView(tv);
setContentView(layout);

et.setHint("Enter Command");
tv.setText(dataStringTot);

startLoop(et, tv);

public void startLoop(final EditText et, final TextView tv) {
    ...
}

如果您的循环是某种不在主线程上运行的线程，您可能需要将其包装在 ui 线程上运行。

runOnUiThread(new Runnable() 
{
    public void run() 
    {
        Log.v("mainActivity", "test");
    }
});