仪表板不显示图标android

我正试图为我的android应用程序设计一个仪表板，并从以下链接获得指导：

http://www.androidhive.info/2011/12/android-dashboard-design-tutorial/

但我面临的问题是图标没有显示出来。我得到一个设置为蓝色活动背景色的空白显示。但仪表板图标不显示。我的代码如下：

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="ActionBarCompat">
        <item name="android:layout_width">fill_parent</item>
        <item name="android:layout_height">50dp</item>
        <item name="android:orientation">horizontal</item>
        <item name="android:background">#2E5EA3</item>
    </style>

    <style name="DashboardButton">
        <item name="android:layout_gravity">center_vertical</item>
        <item name="android:layout_width">wrap_content</item>
        <item name="android:layout_height">wrap_content</item>
        <item name="android:gravity">center_horizontal</item>
        <item name="android:drawablePadding">2dp</item>
        <item name="android:textSize">16dp</item>
        <item name="android:textStyle">bold</item>
        <item name="android:textColor">#fff</item>
        <item name="android:background">@null</item>
    </style>

    <style name="FooterBar">
        <item name="android:layout_width">fill_parent</item>
        <item name="android:layout_height">40dp</item>
        <item name="android:orientation">horizontal</item>
        <item name="android:background">#dedede</item>
    </style>

</resources>

类文件：

package kanix.highrise.com.db;

import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;


public class AndroidDashboardDesignActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.dashboard_layout);

        /**
         * Creating all buttons instances
         * */
        // Dashboard News feed button
        Button btn_newsfeed = (Button) findViewById(R.id.btn_news_feed);

        // Dashboard Friends button
        Button btn_friends = (Button) findViewById(R.id.btn_friends);

        // Dashboard Messages button
        Button btn_messages = (Button) findViewById(R.id.btn_messages);

        // Dashboard Places button
        Button btn_places = (Button) findViewById(R.id.btn_places);

        // Dashboard Events button
        Button btn_events = (Button) findViewById(R.id.btn_events);

        // Dashboard Photos button
        Button btn_photos = (Button) findViewById(R.id.btn_photos);

        /**
         * Handling all button click events
         * */

        // Listening to News Feed button click
        btn_newsfeed.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                // Launching News Feed Screen
              //  Intent i = new Intent(getApplicationContext(), NewsFeedActivity.class);
               // startActivity(i);
            }
        });

        // Listening Friends button click
        btn_friends.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                // Launching News Feed Screen
             //   Intent i = new Intent(getApplicationContext(), FriendsActivity.class);
             //   startActivity(i);
            }
        });

        // Listening Messages button click
        btn_messages.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                // Launching News Feed Screen
             //   Intent i = new Intent(getApplicationContext(), MessagesActivity.class);
             //   startActivity(i);
            }
        });

        // Listening to Places button click
        btn_places.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                // Launching News Feed Screen
               // Intent i = new Intent(getApplicationContext(), PlacesActivity.class);
               // startActivity(i);
            }
        });

        // Listening to Events button click
        btn_events.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                // Launching News Feed Screen
              //  Intent i = new Intent(getApplicationContext(), EventsActivity.class);
              //  startActivity(i);
            }
        });

        // Listening to Photos button click
        btn_photos.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                // Launching News Feed Screen
             //   Intent i = new Intent(getApplicationContext(), PhotosActivity.class);
              //  startActivity(i);
            }
        });
    }
    @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_android_dashboard_design, 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);
    }
}

另一类

package kanix.highrise.com.db;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

/**
 * Created by Mubashir.gul on 30/04/2015.
 */
public class DashboardLayout extends ViewGroup {

    private static final int UNEVEN_GRID_PENALTY_MULTIPLIER = 10;

    private int mMaxChildWidth = 0;
    private int mMaxChildHeight = 0;

    public DashboardLayout(Context context) {
        super(context, null);
    }

    public DashboardLayout(Context context, AttributeSet attrs) {
        super(context, attrs, 0);
    }

    public DashboardLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        mMaxChildWidth = 0;
        mMaxChildHeight = 0;

        // Measure once to find the maximum child size.

        int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
                MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.AT_MOST);
        int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
                MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.AT_MOST);

        final int count = getChildCount();
        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == GONE) {
                continue;
            }

            child.measure(childWidthMeasureSpec, childHeightMeasureSpec);

            mMaxChildWidth = Math.max(mMaxChildWidth, child.getMeasuredWidth());
            mMaxChildHeight = Math.max(mMaxChildHeight, child.getMeasuredHeight());
        }

        // Measure again for each child to be exactly the same size.

        childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
                mMaxChildWidth, MeasureSpec.EXACTLY);
        childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
                mMaxChildHeight, MeasureSpec.EXACTLY);

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == GONE) {
                continue;
            }

            child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
        }

        setMeasuredDimension(
                resolveSize(mMaxChildWidth, widthMeasureSpec),
                resolveSize(mMaxChildHeight, heightMeasureSpec));
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int width = r - l;
        int height = b - t;

        final int count = getChildCount();

        // Calculate the number of visible children.
        int visibleCount = 0;
        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == GONE) {
                continue;
            }
            ++visibleCount;
        }

        if (visibleCount == 0) {
            return;
        }

        // Calculate what number of rows and columns will optimize for even horizontal and
        // vertical whitespace between items. Start with a 1 x N grid, then try 2 x N, and so on.
        int bestSpaceDifference = Integer.MAX_VALUE;
        int spaceDifference;

        // Horizontal and vertical space between items
        int hSpace = 0;
        int vSpace = 0;

        int cols = 1;
        int rows;

        while (true) {
            rows = (visibleCount - 1) / cols + 1;

            hSpace = ((width - mMaxChildWidth * cols) / (cols + 1));
            vSpace = ((height - mMaxChildHeight * rows) / (rows + 1));

            spaceDifference = Math.abs(vSpace - hSpace);
            if (rows * cols != visibleCount) {
                spaceDifference *= UNEVEN_GRID_PENALTY_MULTIPLIER;
            }

            if (spaceDifference < bestSpaceDifference) {
                // Found a better whitespace squareness/ratio
                bestSpaceDifference = spaceDifference;

                // If we found a better whitespace squareness and there's only 1 row, this is
                // the best we can do.
                if (rows == 1) {
                    break;
                }
            } else {
                // This is a worse whitespace ratio, use the previous value of cols and exit.
                --cols;
                rows = (visibleCount - 1) / cols + 1;
                hSpace = ((width - mMaxChildWidth * cols) / (cols + 1));
                vSpace = ((height - mMaxChildHeight * rows) / (rows + 1));
                break;
            }

            ++cols;
        }

        // Lay out children based on calculated best-fit number of rows and cols.

        // If we chose a layout that has negative horizontal or vertical space, force it to zero.
        hSpace = Math.max(0, hSpace);
        vSpace = Math.max(0, vSpace);

        // Re-use width/height variables to be child width/height.
        width = (width - hSpace * (cols + 1)) / cols;
        height = (height - vSpace * (rows + 1)) / rows;

        int left, top;
        int col, row;
        int visibleIndex = 0;
        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == GONE) {
                continue;
            }

            row = visibleIndex / cols;
            col = visibleIndex % cols;

            left = hSpace * (col + 1) + width * col;
            top = vSpace * (row + 1) + height * row;

            child.layout(left, top,
                    (hSpace == 0 && col == cols - 1) ? r : (left + width),
                    (vSpace == 0 && row == rows - 1) ? b : (top + height));
            ++visibleIndex;
        }
    }
}

包kanix.highrise.com.db；
导入android.content.Context；
导入android.util.AttributeSet；
导入android.view.view；
导入android.view.ViewGroup；
/**
*由Mubashir.gul于2015年4月30日创建。
*/
公共类仪表板布局扩展了视图组{
私有静态最终整数不均匀网格惩罚乘数=10；
private int mMaxChildWidth=0；
私有整数mMaxChildHeight=0；
公共仪表板布局（上下文）{
super（上下文，null）；
}
公共仪表板布局（上下文、属性集属性）{
超级（上下文，属性，0）；
}
公共仪表板布局（上下文、属性集属性、int-defStyle）{
超级（上下文、属性、定义样式）；
}
@凌驾
测量时的保护空隙（内部宽度测量等级、内部高度测量等级）{
mMaxChildWidth=0；
mMaxChildHeight=0；
//测量一次以找到最大子大小。
int childwidthmasurespec=MeasureSpec.makeMeasureSpec(
测量等级getSize（宽度测量等级），最大测量等级；
int childHeightMeasureSpec=MeasureSpec.MakeMasureSpec(
测量等级getSize（宽度测量等级），最大测量等级；
最终整数计数=getChildCount（）；
for（int i=0；i<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/home_root"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <!-- Include Action Bar -->
    <include layout="@layout/actionbar_layout"/>

    <!--  Include Fragmented dashboard -->
    <include layout="@layout/fragment_layout"/>

    <!--  Include Footer -->
    <include layout="@layout/footer_layout"/>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<kanix.highrise.com.db.DashboardLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">
    <Button
        android:id="@+id/btn_news_feed"
        style="@style/DashboardButton"
        android:drawableTop="@mipmap/works"
        android:text="News Feed" />

    <!--  Friends Button -->
    <Button
        android:id="@+id/btn_friends"
        style="@style/DashboardButton"
        android:drawableTop="@mipmap/works"
        android:text="Friends"
        android:textColor="#fff"/>

    <!--  Messages Button -->
    <Button
        android:id="@+id/btn_messages"
        style="@style/DashboardButton"
        android:drawableTop="@mipmap/works"
        android:text="Messages" />

    <!--  Places Button -->
    <Button
        android:id="@+id/btn_places"
        style="@style/DashboardButton"
        android:drawableTop="@mipmap/works"
        android:text="Places" />

    <!--  Events Button -->
    <Button
        android:id="@+id/btn_events"
        style="@style/DashboardButton"
        android:drawableTop="@mipmap/works"
        android:text="Events" />

    <!--  Photos Button -->
    <Button
        android:id="@+id/btn_photos"
        style="@style/DashboardButton"
        android:drawableTop="@mipmap/works"
        android:text="Photos" />
</kanix.highrise.com.db.DashboardLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent"  style="@style/FooterBar" >
    <TextView android:text="www.facebook.com"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:textColor="#606060"
        android:gravity="center"
        android:paddingTop="10dip"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="ActionBarCompat">
        <item name="android:layout_width">fill_parent</item>
        <item name="android:layout_height">50dp</item>
        <item name="android:orientation">horizontal</item>
        <item name="android:background">#2E5EA3</item>
    </style>

    <style name="DashboardButton">
        <item name="android:layout_gravity">center_vertical</item>
        <item name="android:layout_width">wrap_content</item>
        <item name="android:layout_height">wrap_content</item>
        <item name="android:gravity">center_horizontal</item>
        <item name="android:drawablePadding">2dp</item>
        <item name="android:textSize">16dp</item>
        <item name="android:textStyle">bold</item>
        <item name="android:textColor">#fff</item>
        <item name="android:background">@null</item>
    </style>

    <style name="FooterBar">
        <item name="android:layout_width">fill_parent</item>
        <item name="android:layout_height">40dp</item>
        <item name="android:orientation">horizontal</item>
        <item name="android:background">#dedede</item>
    </style>

</resources>

<Button
        android:id="@+id/btn_news_feed"
        style="@style/DashboardButton"
        android:drawableTop="@drawable/btn_newsfeed"
        android:text="News Feed" />