小编Nis*_*mad的帖子

我在我的项目中得到多个dex文件定义错误.

我在使用这两种标签的build.gradle以及

dexOptions {
    preDexLibraries = false
}
defaultConfig {
    multiDexEnabled true

}

但仍然得到这个错误.

   Information:Gradle tasks [:app:assembleDebug]
Error:Error converting bytecode to dex:
Cause: com.android.dex.DexException: Multiple dex files define Landroid/support/design/widget/CoordinatorLayout$LayoutParams;
Error:com.android.dex.DexException: Multiple dex files define Landroid/support/design/widget/CoordinatorLayout$LayoutParams;
Error:  at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:661)
Error:  at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:616)
Error:  at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:598)
Error:  at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171)
Error:  at com.android.dx.merge.DexMerger.merge(DexMerger.java:198)
Error:  at com.android.builder.dexing.DexArchiveMergerCallable.call(DexArchiveMergerCallable.java:61)
Error:  at com.android.builder.dexing.DexArchiveMergerCallable.call(DexArchiveMergerCallable.java:36)
Error:  at java.util.concurrent.ForkJoinTask$AdaptedCallable.exec(ForkJoinTask.java:1424)
Error:  at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
Error:  at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
Error:  at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
Error:  at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Error:Execution failed for task ':app:transformDexArchiveWithDexMergerForDebug'.
> com.android.build.api.transform.TransformException: …

我已经更新了所有项目依赖项，并且收到了不同的 R8 错误。

AGPBI: {"kind":"error","text":"java.lang.NullPointerException","sources":[{}],"tool":"D8"}
org.gradle.workers.WorkerExecutionException: There was a failure while executing work items
    at org.gradle.workers.internal.DefaultWorkerExecutor.workerExecutionException(DefaultWorkerExecutor.java:267)
    at org.gradle.workers.internal.DefaultWorkerExecutor.await(DefaultWorkerExecutor.java:249)
    at com.android.build.gradle.internal.tasks.DexArchiveBuilderTaskDelegate.doProcess(DexArchiveBuilderTaskDelegate.kt:227)
    at com.android.build.gradle.internal.tasks.DexArchiveBuilderTask.doTaskAction(DexArchiveBuilderTask.kt:255)
    at com.android.build.gradle.internal.tasks.NewIncrementalTask$taskAction$$inlined$recordTaskAction$1.invoke(BaseTask.kt:69)
    at com.android.build.gradle.internal.tasks.Blocks.recordSpan(Blocks.java:51)
    at com.android.build.gradle.internal.tasks.NewIncrementalTask.taskAction(NewIncrementalTask.kt:46)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:104)
    at org.gradle.api.internal.project.taskfactory.IncrementalInputsTaskAction.doExecute(IncrementalInputsTaskAction.java:32)
    at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:51)
    at org.gradle.api.internal.project.taskfactory.AbstractIncrementalTaskAction.execute(AbstractIncrementalTaskAction.java:25)
    at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:29)
    at org.gradle.api.internal.tasks.execution.TaskExecution$3.run(TaskExecution.java:242)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:29)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:26)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:157)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.run(DefaultBuildOperationRunner.java:47)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:68)
    at org.gradle.api.internal.tasks.execution.TaskExecution.executeAction(TaskExecution.java:227)
    at org.gradle.api.internal.tasks.execution.TaskExecution.executeActions(TaskExecution.java:210)
    at org.gradle.api.internal.tasks.execution.TaskExecution.executeWithPreviousOutputFiles(TaskExecution.java:193)
    at org.gradle.api.internal.tasks.execution.TaskExecution.execute(TaskExecution.java:171)
    at org.gradle.internal.execution.steps.ExecuteStep.executeInternal(ExecuteStep.java:89)
    at org.gradle.internal.execution.steps.ExecuteStep.access$000(ExecuteStep.java:40)
    at org.gradle.internal.execution.steps.ExecuteStep$1.call(ExecuteStep.java:53)
    at …

我正在尝试合并mp3音频文件，但未成功。

这是我的代码。

public static void meargeAudio(List<File> filesToMearge)
{


    while (filesToMearge.size()!=1){

        try {
            FileInputStream fistream1 = new FileInputStream(new File(filesToMearge.get(0).getPath()));  //(/storage/emulated/0/Audio Notes/1455194356500.mp3) first source file
            FileInputStream fistream2 = new FileInputStream(new File(filesToMearge.get(1).getPath()));//second source file

            File file1 = new File(filesToMearge.get(0).getPath());
            boolean deleted = file1.delete();
            File file2 = new File(filesToMearge.get(1).getPath());
            boolean deleted1 = file2.delete();

            SequenceInputStream sistream = new SequenceInputStream(fistream1, fistream2);
            FileOutputStream fostream = new FileOutputStream(new File(filesToMearge.get(0).getPath()),true);//destinationfile

            int temp;

            while ((temp = sistream.read()) != -1) {
                // System.out.print( (char) temp ); // to print at DOS …

我正在开发录音应用程序。在录音期间，我使用像普通录音应用程序一样的可视化工具。但在特定时间，我想在画布可视化工具上绘制可绘制对象（即自定义类扩展 View 类）。

就像这个白色的可绘制点。

这是我的自定义视图类。

public class VisualizerView extends View {
private static final int LINE_WIDTH = 1; // width of visualizer lines
private static final int LINE_SCALE = 75; // scales visualizer lines
private List<VisuallizerItem> visuallizerItems; // amplitudes for line lengths
private int width; // width of this View
private int height; // height of this View
private Paint linePaint; // specifies line drawing characteristics
//Boolean isImage=false;

// constructor
public VisualizerView(Context context, AttributeSet attrs) {
    super(context, attrs); // call …

我需要创建显示像 Highcharts 这样的图表的应用程序。但我没有得到任何图书馆。所以我使用 oxyplot 创建图表。我已经使用这样的 oxyplot 创建了饼图。

var plotView = new PlotView (this);
        plotView.Model = PieViewModel();

        this.AddContentView (plotView,
            new ViewGroup.LayoutParams (ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent));



        public PlotModel PieViewModel()
    {
        var modelP1 = new PlotModel { Title = "Pie Sample1" };
        dynamic seriesP1 = new PieSeries { StrokeThickness = 2.0, InsideLabelPosition = 0.8, AngleSpan = 360, StartAngle = 0 };
        seriesP1.Slices.Add(new PieSlice("Africa", 1030) { IsExploded = false, Fill = OxyColors.PaleVioletRed });
        seriesP1.Slices.Add(new PieSlice("Americas", 929) { IsExploded = true });
        seriesP1.Slices.Add(new PieSlice("Asia", 4157) { IsExploded …