如何制作具有纹理而不是文本颜色或渐变的文本（例如png文件）？像这样的东西。我理解其中的逻辑，即我应该使文本颜色透明并放在文本位图下面。我想我不能用Textview来实现这一点。我不知道如何使用画布或OpenGL来实现它。有什么想法吗？
这里有一种使用PorterDuffXfermode的方法。
public class MainActivity extends Activity {
private EditText mEditText;
private ImageView mImageView;
private Bitmap mTexture;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mEditText = (EditText) findViewById(R.id.activity_main_edittext);
mImageView = (ImageView) findViewById(R.id.activity_main_image);
mTexture = BitmapFactory.decodeResource(getResources(),
R.drawable.texture);
}
public void onTextCreate(View v) {
final String text = mEditText.getEditableText().toString();
Bitmap result = Bitmap.createBitmap(mTexture.getWidth(),
mTexture.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(result);
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setTextSize(200);
paint.setARGB(255, 0, 0, 0);
canvas.drawText(text, 200, 200, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(mTexture, 0, 0, paint);
paint.setXfermode(null);
mImageView.setImageBitmap(result);
}
}
布局非常简单：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<EditText
android:id="@+id/activity_main_edittext"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:hint="Write a sample text" />
<ImageView
android:id="@+id/activity_main_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true" />
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:onClick="onTextCreate"
android:text="Do it!" />
</RelativeLayout>
此代码使用canvas.drawText()编写文本。如果您想使用常规TextView，您可以：
- 创建
TextView - 设置文本
- 使用
textView.draw(canvas);将TextView绘制到画布中 - 使用
canvas.drawBitmap()代替canvas.drawText()
这是http://teamyoda.wordpress.com/2012/07/23/drawing-text-in-opengl-for-android/-JVitela 的回答
// Create an empty, mutable bitmap
Bitmap bitmap = Bitmap.createBitmap(256, 256, Bitmap.Config.ARGB_4444);
// get a canvas to paint over the bitmap
Canvas canvas = new Canvas(bitmap);
bitmap.eraseColor(0);
// get a background image from resources
// note the image format must match the bitmap format
Drawable background = context.getResources().getDrawable(R.drawable.background);
background.setBounds(0, 0, 256, 256);
background.draw(canvas); // draw the background to our bitmap
// Draw the text
Paint textPaint = new Paint();
textPaint.setTextSize(32);
textPaint.setAntiAlias(true);
textPaint.setARGB(0xff, 0×00, 0×00, 0×00);
// draw the text centered
canvas.drawText(“Hello World”, 16,112, textPaint);
//Generate one texture pointer…
gl.glGenTextures(1, textures, 0);
//…and bind it to our array
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
//Create Nearest Filtered Texture
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
//Different possible texture parameters, e.g. GL10.GL_CLAMP_TO_EDGE
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_REPEAT);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_REPEAT);
//Use the Android GLUtils to specify a two-dimensional texture image from our bitmap
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
//Clean up
bitmap.recycle();
很抱歉这么晚才发布，但我想我会有所帮助。因此，要制作有纹理的文本，例如，在layout/文件夹中有一个名为my_layout.xml的文件，其定义如下：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/some_text_id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="@string/some_text"/>
</RelativeLayout>
在drawable/文件夹中，您有一个名为texture.png的图片，您只需在java代码中引用（例如在类MainActivity中）：
public class MainActivity extends Activity
{
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.my_layout);
TextView welcome = (TextView) findViewById(R.id.some_text_id);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.texture);
Shader shader = new BitmapShader(bitmap,Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
welcome.getPaint().setShader(shader);
}
}