Android绘图的Paint.setBlendMode导致崩溃问题。

huangapple
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英文:

Android Paint.setBlendMode Crash

问题

  1. 我正在使用绘图工具（paint）在画布上绘制一些文本上方的突出显示框（highlight boxes）。我需要将绘图工具的混合模式（blendmode）设置为multiply。
  3. ```java
  4. Paint paint = new Paint();
  5. paint.setColor(Color.YELLOW);
  6. paint.setBlendMode(BlendMode.MULTIPLY);

然而，这会导致崩溃：
java.lang.NoClassDefFoundError: Failed resolution of: Landroid/graphics/BlendMode;

在我的Oneplus 6T上不会发生这种情况，那里它可以正常工作。然而，在我的LG V10上会出现这种崩溃。

有关如何修复这个问题的任何想法吗？

build.gradle:

  1. apply plugin: 'com.android.application';
  3. android {
  4.     compileSdkVersion 29
  5.     buildToolsVersion "29.0.3"
  7.     defaultConfig {
  8.         applicationId "com.example.test"
  9.         minSdkVersion 24
  10.         targetSdkVersion 29
  11.         multiDexEnabled true
  12.         versionCode 1
  13.         versionName "1.0"
  15.         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
  16.     }
  18.     buildTypes {
  19.         release {
  20.             minifyEnabled false
  21.             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
  22.         }
  23.     }
  24. }
  26. dependencies {
  27.     implementation fileTree(dir: 'libs', include: ['*.jar'])
  29.     implementation 'androidx.appcompat:appcompat:1.1.0'
  30.     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
  31.     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
  32.     testImplementation 'junit:junit:4.12'
  33.     androidTestImplementation 'androidx.test.ext:junit:1.1.1'
  34.     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
  36.     implementation 'com.google.android.material:material:1.3.0-alpha01'
  38.     implementation 'com.github.barteksc:android-pdf-viewer:3.2.0-beta.1'
  39.     implementation 'com.tom_roush:pdfbox-android:1.8.10.1'
  40.     implementation files('libs\\YouTubeAndroidPlayerApi.jar')
  41. }
  2. <details>
  3. <summary>英文:</summary>
  5. I&#39;m using paint to draw highlight boxes on top of some text using a canvas. I need to set the paint blendmode to multiply.

Paint paint = new Paint();
paint.setColor(Color.YELLOW);
paint.setBlendMode(BlendMode.MULTIPLY);

  2. This however, causes a crash:
  3. **java.lang.NoClassDefFoundError: Failed resolution of: Landroid/graphics/BlendMode;**
  5. It doesn&#39;t happen on my Oneplus 6T where it works perfectly. On my LG V10 however, this crash happens.
  7. Any ideas on how to fix this?
  9. **build.gradle:**

apply plugin: 'com.android.application'

android {
compileSdkVersion 29
buildToolsVersion "29.0.3"

  1. defaultConfig {
  2.     applicationId &quot;com.example.test&quot;
  3.     minSdkVersion 24
  4.     targetSdkVersion 29
  5.     multiDexEnabled true
  6.     versionCode 1
  7.     versionName &quot;1.0&quot;
  9.     testInstrumentationRunner &quot;androidx.test.runner.AndroidJUnitRunner&quot;
  10. }
  12. buildTypes {
  13.     release {
  14.         minifyEnabled false
  15.         proguardFiles getDefaultProguardFile(&#39;proguard-android-optimize.txt&#39;), &#39;proguard-rules.pro&#39;
  16.     }
  17. }

}

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])

  1. implementation &#39;androidx.appcompat:appcompat:1.1.0&#39;
  2. implementation &#39;androidx.constraintlayout:constraintlayout:1.1.3&#39;
  3. implementation &#39;androidx.legacy:legacy-support-v4:1.0.0&#39;
  4. testImplementation &#39;junit:junit:4.12&#39;
  5. androidTestImplementation &#39;androidx.test.ext:junit:1.1.1&#39;
  6. androidTestImplementation &#39;androidx.test.espresso:espresso-core:3.2.0&#39;
  8. implementation &#39;com.google.android.material:material:1.3.0-alpha01&#39;
  10. implementation &#39;com.github.barteksc:android-pdf-viewer:3.2.0-beta.1&#39;
  11. implementation &#39;com.tom_roush:pdfbox-android:1.8.10.1&#39;
  12. implementation files(&#39;libs\\YouTubeAndroidPlayerApi.jar&#39;)

}

  3. </details>
  6. # 答案1
  7. **得分**: 1
  9. ***已解决***
  11. 显然，setBlendMode 要求在 API 级别 29 中引入，这就是它在我运行 Android 7 的 V10 上不起作用的原因。我发现的解决方案是简单地使用较旧的 Paint.setXfermode，并选择 PorterDuff 乘法模式。
  13. ```java
  14. Paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.MULTIPLY));

参见：https://developer.android.com/reference/android/graphics/PorterDuff.Mode

英文:

*Solved

So apparently setBlendMode requires was introduced in API-level 29 and this is the reason it didn't work on my V10 which is running Android 7. The solution that i discovered was to simply use the older Paint.setXfermode with PorterDuff Multiply mode.

  1. Paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.MULTIPLY));

See: https://developer.android.com/reference/android/graphics/PorterDuff.Mode

huangapple
  • 本文由 发表于 2020年6月29日 16:38:18
  • 转载请务必保留本文链接：https://go.coder-hub.com/62634249.html
  • android
  • androidx
  • java
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