为什么我不能将此运行时创建位图作为声明到片段中的 ImageView 的内容？
Why I can't put this runtime created Bitmap as content o an ImageView declared into a Fragment?
我绝对是 Android 开发新手，我正在开发我的第一个与 Udacity 初学者课程相关的教育应用程序。
应用程序的想法非常简单：它是一个烹饪食谱应用程序，其中使用从一个 recepy 切换到另一个交换在主 activity.
中向右或向左滑动。
所以这是我的 GitHub 与此应用程序相关的存储库：https://github.com/AndreaNobili/PastaFromRome
为了从一个 recepy 交换到另一个我使用了片段，所以基本上我有一个 activity_man.xml 文件，它只包含 header 和一个 viewpager对于片段：
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
然后我有 fragment_screen_slide_page.xml 表示与单个食谱相关的幻灯片，如下所示：
<!-- Dummy content. -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="0dp">
<ImageView
android:id="@+id/imageView1"
android:layout_width="fill_parent"
android:scaleType="fitXY"
android:layout_height="250dp" />
<!--
android:src="@drawable/carbonara"/>
android:background="@drawable/carbonara" />
-->
<TextView android:id="@android:id/text1"
style="@style/pastaTitleTextStyle" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<LinearLayout
android:layout_width="0px"
android:layout_weight="1"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
style="@style/HeaderTextStyle"
android:text="Difficoltà:" />
<ImageView
android:id="@+id/difficultyContainer"
android:layout_width="fill_parent"
android:scaleType="fitXY"
android:layout_height="55dp" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
此视图是一个片段，显示时包含当前配方。
它包含第一个 ImageView，其 ID imageView1 显示与当前食谱相关的图像，它工作正常。
然后它包含第二个 ImageView，其 ID difficultyContainer 是在运行时从应用程序创建的难度排名图像。这就是我要发疯的地方!!!
这是处理片段逻辑的 ScreenSlidePageFragment class（扩展 Fragment）：
/**
* A fragment representing a single step in a wizard. The fragment shows a dummy title indicating
* the page number, along with some dummy text.
*
*/
public class ScreenSlidePageFragment extends Fragment {
private static final String TAG = "ScreenSlidePageFragment";
/**
* The argument key for the page number this fragment represents.
*/
public static final String ARG_PAGE = "page";
/**
* The fragment's page number, which is set to the argument value for {@link #ARG_PAGE}.
*/
private int mPageNumber;
private static Context context;
/**
* Factory method for this fragment class. Constructs a new fragment for the given page number.
*/
public static ScreenSlidePageFragment create(int pageNumber, Context baseContext) {
ScreenSlidePageFragment fragment = new ScreenSlidePageFragment();
Bundle args = new Bundle();
args.putInt(ARG_PAGE, pageNumber);
fragment.setArguments(args);
context = baseContext;
return fragment;
}
public ScreenSlidePageFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPageNumber = getArguments().getInt(ARG_PAGE);
}
/**
* Method that will be called when the "pasta slider" is slided right or left
* @param inflater
* @param container
* @param savedInstanceState
* @return
*/
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
System.out.println("PAGE NUMBER: "+ mPageNumber);
// Obtain the colosseum_icon.png from the rsources as a Drawable:
//Drawable drawable = getResources().getDrawable(R.drawable.colosseum_icon);
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_screen_slide_page, container, false);
ImageView imgSlideView = (ImageView) rootView.findViewById(R.id.imageView1);
/* Retrieve the ImageView having id="difficultyContainer" (where to put the diifficulty
image created):
*/
//ImageView difficultyContainerImageView = (ImageView) rootView.findViewById(R.id.difficultyContainer);
// Load the 2 images for the creation of the "difficulty graphic":
Bitmap chefHatWhite = BitmapFactory.decodeResource(getResources(), R.drawable.chef_hat_white);
Bitmap chefHatOk = BitmapFactory.decodeResource(getResources(), R.drawable.chef_hat_ok);
// Where the previus image will be drawn:
//Canvas canvas = new Canvas();
Canvas difficultyCanvas = creaImgDifficulty();
//switch (mPageNumber + 1) {
switch (mPageNumber) {
case 0:
imgSlideView.setImageResource(R.drawable.carbonara);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.carbonara));
ImageView difficultyContainerImageView1 = (ImageView) rootView.findViewById(R.id.difficultyContainer);
difficultyContainerImageView1.setImageDrawable(new BitmapDrawable(getResources(), ImgUtility.createRankingImg(context, 3)));
break;
case 1:
imgSlideView.setImageResource(R.drawable.amatriciana);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.amatriciana));
break;
case 2:
imgSlideView.setImageResource(R.drawable.gricia_m);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.gricia));
break;
case 3:
imgSlideView.setImageResource(R.drawable.cacio_e_pepe);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.cacio_e_pepe));
break;
case 4:
imgSlideView.setImageResource(R.drawable.ajo_ojo_e_peperoncino);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.ajo_ojo_peperoncino));
break;
}
return rootView;
}
private void createImg(ImageView imgview) {
Canvas canvas;
Bitmap star = BitmapFactory.decodeResource(getResources(), R.drawable.star);
Bitmap output = Bitmap.createBitmap(32, 32, Bitmap.Config.ARGB_8888);
canvas = new Canvas(output);
canvas.drawBitmap(star, star.getWidth() + 2, 0, null);
imgview.setImageDrawable(new BitmapDrawable(getResources(), output));
}
private Canvas creaImgDifficulty() {
Canvas canvas;
Bitmap chefHatOk = BitmapFactory.decodeResource(getResources(), R.drawable.chef_hat_ok);
Bitmap output = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888);
canvas = new Canvas(output);
int space = 10; // the space between images
for(int i = 0; i < 3; i++) {
canvas.drawBitmap(chefHatOk, i * (chefHatOk.getWidth() + space), 0, null);
}
return canvas;
}
/**
* Returns the page number represented by this fragment object.
*/
public int getPageNumber() {
return mPageNumber;
}
}
所以基本上进入 onCreateView() 方法（我认为是在加载当前片段时执行的）我有 mPageNumber指定与特定配方相关的加载片段的变量，并且有一个 switch case 用于将此配方的特定信息加载到此片段中，例如：
案例 0: 这是第一个名为 carbonara 的食谱，所以它把 carbonara.png image (R.drawable.carbonara) into the previous ImageView havving id=imageView1 defined into the fragment_screen_slide_page.xml 文件。
它工作正常。
问题发生在我之前的代码中：
ImageView difficultyContainerImageView1 = (ImageView) rootView.findViewById(R.id.difficultyContainer);
difficultyContainerImageView1.setImageDrawable(new BitmapDrawable(getResources(), ImgUtility.createRankingImg(context, 3)));
如您在代码中所见，difficultyContainerImageView1 标识具有 id=difficultyContainer[=75 的 ImageView =] 在我的片段中。这里我设置了一个由 ImgUtility.createRankingImg() 方法创建的图像。
public class ImgUtility {
/**
* Method that create the images related to the difficulty of a recepy
* @param context
* @param difficulty that represent the number of chef_hat_ok into the final image
* @return a Bitmap representing the difficult of a recepy
*/
public static Bitmap createRankingImg(Context context, int difficulty) {
// Create a Bitmap image starting from the star.png into the "/res/drawable/" directory:
Bitmap myBitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.chef_hat_ok);
// Create a new image bitmap having width to hold 5 star.png image:
Bitmap tempBitmap = Bitmap.createBitmap(myBitmap.getWidth() * 5, myBitmap.getHeight(), Bitmap.Config.RGB_565);
Canvas tempCanvas = new Canvas(tempBitmap);
// Draw the image bitmap into the cavas:
tempCanvas.drawBitmap(myBitmap, 0, 0, null);
tempCanvas.drawBitmap(myBitmap, myBitmap.getWidth(), 0, null);
tempCanvas.drawBitmap(myBitmap, myBitmap.getWidth() * 2, 0, null);
tempCanvas.drawBitmap(myBitmap, myBitmap.getWidth() * 3, 0, null);
tempCanvas.drawBitmap(myBitmap, myBitmap.getWidth() * 4, 0, null);
return tempBitmap;
}
}
这种方法应该没问题，因为在我看来 return 一个位图，但是这张图片没有显示在具有 id 的片段 ImageView 中=难度容器
进入logcat我可以看到以下错误日志，但我不知道是否与我的问题有关：
08-21 19:38:12.315 4239-4925/com.example.android.pastafromrome W/OpenGLRenderer: Bitmap too large to be uploaded into a texture (8730x1836, max=4096x4096)
08-21 19:38:12.335 4239-4925/com.example.android.pastafromrome W/OpenGLRenderer: Bitmap too large to be uploaded into a texture (8730x1836, max=4096x4096)
08-21 19:38:12.335 4239-4925/com.example.android.pastafromrome W/OpenGLRenderer: Bitmap too large to be uploaded into a texture (8730x1836, max=4096x4096)
为什么？我错过了什么？我该如何解决这个问题？如果您看到我的 GitHub 存储库并帮助我修复它，我将非常高兴。
问题是 Android 会自动调整 chef_hat_ok 到 1746px 宽度（我想这取决于设备）。看起来不错，但你做了 5 个，5 x 1746px 是 8370，纹理不能容纳它。
解决方案：禁用缩放或放置依赖于密度的资源（未选中该选项）。
禁用缩放。
ImgUtility.java
BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = false;
Bitmap myBitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.chef_hat_ok, options);
编辑：您需要将密度设置为 canvas tempCanvas.setDensity(myBitmap.getDensity());
Edit2：我还建议对难度容器进行一些更改
<ImageView
android:id="@+id/difficultyContainer"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:scaleType="centerInside"
android:adjustViewBounds="true" />
我绝对是 Android 开发新手，我正在开发我的第一个与 Udacity 初学者课程相关的教育应用程序。
应用程序的想法非常简单：它是一个烹饪食谱应用程序，其中使用从一个 recepy 切换到另一个交换在主 activity.
中向右或向左滑动。所以这是我的 GitHub 与此应用程序相关的存储库：https://github.com/AndreaNobili/PastaFromRome
为了从一个 recepy 交换到另一个我使用了片段，所以基本上我有一个 activity_man.xml 文件，它只包含 header 和一个 viewpager对于片段：
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
然后我有 fragment_screen_slide_page.xml 表示与单个食谱相关的幻灯片，如下所示：
<!-- Dummy content. -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="0dp">
<ImageView
android:id="@+id/imageView1"
android:layout_width="fill_parent"
android:scaleType="fitXY"
android:layout_height="250dp" />
<!--
android:src="@drawable/carbonara"/>
android:background="@drawable/carbonara" />
-->
<TextView android:id="@android:id/text1"
style="@style/pastaTitleTextStyle" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<LinearLayout
android:layout_width="0px"
android:layout_weight="1"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
style="@style/HeaderTextStyle"
android:text="Difficoltà:" />
<ImageView
android:id="@+id/difficultyContainer"
android:layout_width="fill_parent"
android:scaleType="fitXY"
android:layout_height="55dp" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
此视图是一个片段，显示时包含当前配方。
它包含第一个 ImageView，其 ID imageView1 显示与当前食谱相关的图像，它工作正常。
然后它包含第二个 ImageView，其 ID difficultyContainer 是在运行时从应用程序创建的难度排名图像。这就是我要发疯的地方!!!
这是处理片段逻辑的 ScreenSlidePageFragment class（扩展 Fragment）：
/**
* A fragment representing a single step in a wizard. The fragment shows a dummy title indicating
* the page number, along with some dummy text.
*
*/
public class ScreenSlidePageFragment extends Fragment {
private static final String TAG = "ScreenSlidePageFragment";
/**
* The argument key for the page number this fragment represents.
*/
public static final String ARG_PAGE = "page";
/**
* The fragment's page number, which is set to the argument value for {@link #ARG_PAGE}.
*/
private int mPageNumber;
private static Context context;
/**
* Factory method for this fragment class. Constructs a new fragment for the given page number.
*/
public static ScreenSlidePageFragment create(int pageNumber, Context baseContext) {
ScreenSlidePageFragment fragment = new ScreenSlidePageFragment();
Bundle args = new Bundle();
args.putInt(ARG_PAGE, pageNumber);
fragment.setArguments(args);
context = baseContext;
return fragment;
}
public ScreenSlidePageFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPageNumber = getArguments().getInt(ARG_PAGE);
}
/**
* Method that will be called when the "pasta slider" is slided right or left
* @param inflater
* @param container
* @param savedInstanceState
* @return
*/
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
System.out.println("PAGE NUMBER: "+ mPageNumber);
// Obtain the colosseum_icon.png from the rsources as a Drawable:
//Drawable drawable = getResources().getDrawable(R.drawable.colosseum_icon);
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_screen_slide_page, container, false);
ImageView imgSlideView = (ImageView) rootView.findViewById(R.id.imageView1);
/* Retrieve the ImageView having id="difficultyContainer" (where to put the diifficulty
image created):
*/
//ImageView difficultyContainerImageView = (ImageView) rootView.findViewById(R.id.difficultyContainer);
// Load the 2 images for the creation of the "difficulty graphic":
Bitmap chefHatWhite = BitmapFactory.decodeResource(getResources(), R.drawable.chef_hat_white);
Bitmap chefHatOk = BitmapFactory.decodeResource(getResources(), R.drawable.chef_hat_ok);
// Where the previus image will be drawn:
//Canvas canvas = new Canvas();
Canvas difficultyCanvas = creaImgDifficulty();
//switch (mPageNumber + 1) {
switch (mPageNumber) {
case 0:
imgSlideView.setImageResource(R.drawable.carbonara);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.carbonara));
ImageView difficultyContainerImageView1 = (ImageView) rootView.findViewById(R.id.difficultyContainer);
difficultyContainerImageView1.setImageDrawable(new BitmapDrawable(getResources(), ImgUtility.createRankingImg(context, 3)));
break;
case 1:
imgSlideView.setImageResource(R.drawable.amatriciana);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.amatriciana));
break;
case 2:
imgSlideView.setImageResource(R.drawable.gricia_m);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.gricia));
break;
case 3:
imgSlideView.setImageResource(R.drawable.cacio_e_pepe);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.cacio_e_pepe));
break;
case 4:
imgSlideView.setImageResource(R.drawable.ajo_ojo_e_peperoncino);
((TextView) rootView.findViewById(android.R.id.text1)).setText(getString(R.string.ajo_ojo_peperoncino));
break;
}
return rootView;
}
private void createImg(ImageView imgview) {
Canvas canvas;
Bitmap star = BitmapFactory.decodeResource(getResources(), R.drawable.star);
Bitmap output = Bitmap.createBitmap(32, 32, Bitmap.Config.ARGB_8888);
canvas = new Canvas(output);
canvas.drawBitmap(star, star.getWidth() + 2, 0, null);
imgview.setImageDrawable(new BitmapDrawable(getResources(), output));
}
private Canvas creaImgDifficulty() {
Canvas canvas;
Bitmap chefHatOk = BitmapFactory.decodeResource(getResources(), R.drawable.chef_hat_ok);
Bitmap output = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888);
canvas = new Canvas(output);
int space = 10; // the space between images
for(int i = 0; i < 3; i++) {
canvas.drawBitmap(chefHatOk, i * (chefHatOk.getWidth() + space), 0, null);
}
return canvas;
}
/**
* Returns the page number represented by this fragment object.
*/
public int getPageNumber() {
return mPageNumber;
}
}
所以基本上进入 onCreateView() 方法（我认为是在加载当前片段时执行的）我有 mPageNumber指定与特定配方相关的加载片段的变量，并且有一个 switch case 用于将此配方的特定信息加载到此片段中，例如：
案例 0: 这是第一个名为 carbonara 的食谱，所以它把 carbonara.png image (R.drawable.carbonara) into the previous ImageView havving id=imageView1 defined into the fragment_screen_slide_page.xml 文件。
它工作正常。
问题发生在我之前的代码中：
ImageView difficultyContainerImageView1 = (ImageView) rootView.findViewById(R.id.difficultyContainer);
difficultyContainerImageView1.setImageDrawable(new BitmapDrawable(getResources(), ImgUtility.createRankingImg(context, 3)));
如您在代码中所见，difficultyContainerImageView1 标识具有 id=difficultyContainer[=75 的 ImageView =] 在我的片段中。这里我设置了一个由 ImgUtility.createRankingImg() 方法创建的图像。
public class ImgUtility {
/**
* Method that create the images related to the difficulty of a recepy
* @param context
* @param difficulty that represent the number of chef_hat_ok into the final image
* @return a Bitmap representing the difficult of a recepy
*/
public static Bitmap createRankingImg(Context context, int difficulty) {
// Create a Bitmap image starting from the star.png into the "/res/drawable/" directory:
Bitmap myBitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.chef_hat_ok);
// Create a new image bitmap having width to hold 5 star.png image:
Bitmap tempBitmap = Bitmap.createBitmap(myBitmap.getWidth() * 5, myBitmap.getHeight(), Bitmap.Config.RGB_565);
Canvas tempCanvas = new Canvas(tempBitmap);
// Draw the image bitmap into the cavas:
tempCanvas.drawBitmap(myBitmap, 0, 0, null);
tempCanvas.drawBitmap(myBitmap, myBitmap.getWidth(), 0, null);
tempCanvas.drawBitmap(myBitmap, myBitmap.getWidth() * 2, 0, null);
tempCanvas.drawBitmap(myBitmap, myBitmap.getWidth() * 3, 0, null);
tempCanvas.drawBitmap(myBitmap, myBitmap.getWidth() * 4, 0, null);
return tempBitmap;
}
}
这种方法应该没问题，因为在我看来 return 一个位图，但是这张图片没有显示在具有 id 的片段 ImageView 中=难度容器
进入logcat我可以看到以下错误日志，但我不知道是否与我的问题有关：
08-21 19:38:12.315 4239-4925/com.example.android.pastafromrome W/OpenGLRenderer: Bitmap too large to be uploaded into a texture (8730x1836, max=4096x4096)
08-21 19:38:12.335 4239-4925/com.example.android.pastafromrome W/OpenGLRenderer: Bitmap too large to be uploaded into a texture (8730x1836, max=4096x4096)
08-21 19:38:12.335 4239-4925/com.example.android.pastafromrome W/OpenGLRenderer: Bitmap too large to be uploaded into a texture (8730x1836, max=4096x4096)
为什么？我错过了什么？我该如何解决这个问题？如果您看到我的 GitHub 存储库并帮助我修复它，我将非常高兴。
问题是 Android 会自动调整 chef_hat_ok 到 1746px 宽度（我想这取决于设备）。看起来不错，但你做了 5 个，5 x 1746px 是 8370，纹理不能容纳它。
解决方案：禁用缩放或放置依赖于密度的资源（未选中该选项）。
禁用缩放。
ImgUtility.java
BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = false;
Bitmap myBitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.chef_hat_ok, options);
编辑：您需要将密度设置为 canvas tempCanvas.setDensity(myBitmap.getDensity());
Edit2：我还建议对难度容器进行一些更改
<ImageView
android:id="@+id/difficultyContainer"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:scaleType="centerInside"
android:adjustViewBounds="true" />