如何从Java代码向Android App添加图像

Question

My friend and I are making an android app for our class project. We are making and app with tabs. We want to know if there is a way to use one xml file for the tabs and if we can add pictures straight from the java code or do we need to make an xml file for each individual tab. If we do how would we go about keeping the same formatting for all the tabs.

The code i provide is the main.xml in which we have attached some pictures to. the tab.xml is the xml layout which we formatted the tabs. the SalesExecutiveDashboard.java is the main activity that calls the other tab activities. Lastly HomeTab.java is and example of on our tab codes.

Thanks for all the help provided

main.xml

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout
 android:layout_height="fill_parent"
 android:layout_width="fill_parent"
 android:orientation="vertical"
 xmlns:android="http://schemas.android.com/apk/res/android">
<TextView 
 android:layout_height="wrap_content"
 android:layout_width="wrap_content"
 android:layout_margin="1dp" 
 android:text="@string/overall_sales"
 android:id="@+id/pieChartView"/>
<ImageView 
 android:layout_height="fill_parent"
 android:layout_width="fill_parent" 
 android:id="@+id/pie_chart" 
 android:src="@drawable/piechartsmall"/>
</LinearLayout>

tab.xml

<?xml version="1.0" encoding="UTF-8"?>
<TabHost
 android:id="@android:id/tabhost" 
 xmlns:android="http://schemas.android.com/apk/res/android" 
 android:layout_height="fill_parent" 
 android:layout_width="fill_parent"> 

<ScrollView 
 xmlns:android="http://schemas.android.com/apk/res/android"    
 android:layout_height="fill_parent"
 android:layout_width="fill_parent">

<LinearLayout android:id="@+id/LinearLayout01"
 android:layout_height="wrap_content" 
 android:layout_width="fill_parent" 
 android:orientation="vertical">

<HorizontalScrollView 
 android:layout_height="wrap_content"
 android:layout_width="wrap_content" 
 android:scrollbars="none"
 android:fillViewport="true">

<TabWidget android:id="@android:id/tabs"
 android:layout_height="40dp" 
 android:layout_width="wrap_content"
 android:layout_gravity="bottom"
 android:gravity="bottom">

</TabWidget>
</HorizontalScrollView>

<FrameLayout
 android:id="@android:id/tabcontent"
 android:layout_height="fill_parent"
 android:layout_width="fill_parent">
</FrameLayout>
</LinearLayout>
</ScrollView>
</TabHost>

SaleExecutiveDashboard.java

package com.androidpeople.tab;

import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TabHost;
import android.widget.TabHost.TabSpec;

public class SalesExecutiveDashboard extends TabActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tab);

        /* TabHost will have Tabs */
        //TabHost tabHost = (TabHost)findViewById(android.R.id.tabhost);

        TabHost tabHost=getTabHost();

        /* TabSpec used to create a new tab. 
         * By using TabSpec only we can able to setContent to the tab.
         * By using TabSpec setIndicator() we can set name to tab. */

        /* tid1 is firstTabSpec Id. Its used to access outside. */
        TabSpec HomeTabSpec = tabHost.newTabSpec("Tab1");
        TabSpec RevExpTabSpec = tabHost.newTabSpec("Tab2");
        TabSpec AccountTabSpec = tabHost.newTabSpec("Tab3");
        TabSpec DistroTabSpec = tabHost.newTabSpec("Tab4");
        TabSpec SBPTabSpec = tabHost.newTabSpec("Tab5");
        TabSpec AlertTabSpec = tabHost.newTabSpec("Tab6");

        /* TabSpec setIndicator() is used to set name for the tab. */
        /* TabSpec setContent() is used to set content for a particular tab. */
        HomeTabSpec.setIndicator("  Home  ").setContent(new Intent(this,HomeTab.class));

        RevExpTabSpec.setIndicator("  Rev/Exp  ").setContent(new Intent(this,RevExpTab.class));
        AccountTabSpec.setIndicator("  Accounts  ").setContent(new Intent(this,AccountsTab.class));
        DistroTabSpec.setIndicator("  Distribution  ").setContent(new Intent(this,DistroTab.class));
        SBPTabSpec.setIndicator("  Sales by Product  ").setContent(new Intent(this,SBPTab.class));
        AlertTabSpec.setIndicator("  Alerts  ").setContent(new Intent(this,AlertTab.class));

        /* Add tabSpec to the TabHost to display. */
        tabHost.addTab(HomeTabSpec);
        tabHost.addTab(RevExpTabSpec);
        tabHost.addTab(AccountTabSpec);
        tabHost.addTab(DistroTabSpec);
        tabHost.addTab(SBPTabSpec);
        tabHost.addTab(AlertTabSpec);

    }
}

HomeTab.java

package com.androidpeople.tab;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.widget.ImageView;

public class HomeTab extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        /* First Tab Content */
        ImageView image = (ImageView) findViewById(R.id.pie_chart);

        //TextView textView = new TextView(this);
        //textView.setText("This is the Home Tab");
        //setContentView(textView);
        setContentView(R.layout.main);

    }
}

Answer 1

Yes, you can use one layout resource multiple times. It only specifies the appearance. As for the images, so long as they are in your drawable resources, you would just assign them to your ImageView as you wished.

//hold the integer resource id of your image
Integer img = R.drawable.<<imageid>>;

//get your ImageView
ImageView iView = (ImageView) findViewById(R.id.<<viewname>>);

//assign your image
iView.setImageResource(img);

Another option is in the drawable directory, you can create xml 'selectors' to tell your app which image to use dependent on some condition. For example, let's say you have an ImageButton and want a different image to show if it's disabled. You can have a selector like the following in the drawable directory to use the images in your drawable-h/l/mdpi directories:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/aps/res/android">
    <item android:state_enabled="false" android:drawable="@drawable/<<disabledImage>>"/>
    <item android:drawable="@drawable/<<defaultImage>>"?>
</selector>

You could then use this selector in your layout.

<Button android:layout_width="fill_parent" android:id="@+id/btn1" android:text="btn1" android:textSize="20dp" android:textColor="@android:color/transparent" android:background="@drawable/<<selectorName>>" android:layout_height="fill_parent" android:onClick="<<clickevent>>" />

I know this is an old question, but hope this helps somebody.

Answer 2

First of all you need to edit your HomeTab Activity onCreate method like :

  @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); /* First Tab Content */ ImageView image = (ImageView) findViewById(R.id.pie_chart); //TextView textView = new TextView(this); //textView.setText("This is the Home Tab"); //setContentView(textView); } 

We can casting any controll after set it layout file you cant casting first :)

Then after your MainActivity content TabHost so you can set it inBuild Listner like :

 tabHost.setOnTabChangedListener(new OnTabChangeListener() { @Override public void onTabChanged(String arg0) { int pos=tabHost.getCurrentTab(); Toast.makeText(this,""+pos,Toast.LENGTH_SHORT).show(); SharedPreferences pref=getSharedPreferences(YOUR_PREFERENC,0); SharedPreferences.Editor et = pref.edit(); et.putInt(YOUR_POS_KEY,pos); et.commit(); } }); 

you can use this SharedPreferences value in your sub Activity and check position condition to set dynamic image in your one layout or only in one Java file

i hope it work

Happy Coding ...