我試圖從MainActivity.java創建佈局,但我的模擬器沒有顯示佈局和從MainActivity.java創建的按鈕。我必須改變activity_main.xml中的內容嗎? 下面是代碼,無法從MainActivity.java創建佈局
package com.example.pratt.myapplication;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.util.Log;
import android.widget.RelativeLayout;
import android.widget.Button;
import android.graphics.Color;
public class MainActivity extends ActionBarActivity {
private static final String TAG="My Message";
@Override
protected void onCreate(Bundle savedInstanceState) {
/*
*/
super.onCreate(savedInstanceState);
RelativeLayout myLayout=new RelativeLayout(this);
Button blue_button=new Button(this);
myLayout.setBackgroundColor(Color.RED);
myLayout.addView(blue_button);
blue_button.setText("Blue Button");
Log.i(TAG,"onCreate");
setContentView(myLayout);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
它沒有工作 –