Question

我试图从画廊中添加一张照片，用画布将图像弄圆，然后放入ImageView中，但是我总是遇到此错误：

致命异常：主要流程：app.innova.cristobal.neton，PID：8016 java.lang.RuntimeException：无法交付结果 ResultInfo {who = null，request = 1，result = -1，data = Intent { dat = content：//com.android.providers.media.documents/document/image：38 flg = 0x1}}活动 {app.innova.cristobal.neton / app.innova.cristobal.neton.Principal3Activity}： java.lang.NullPointerException：尝试调用虚拟方法'int 空对象引用上的android.graphics.Bitmap.getWidth（）' 在android.app.ActivityThread.deliverResults（ActivityThread.java:3699）在 android.app.ActivityThread.handleSendResult（ActivityThread.java:3742）在android.app.ActivityThread.-wrap16（ActivityThread.java）在 android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1393）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:148）在android.app.ActivityThread.main（ActivityThread.java:5417）在java.lang.reflect.Method.invoke（本机方法）在 com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:726）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:616）原因：java.lang.NullPointerException：尝试调用虚拟空对象上的方法'int android.graphics.Bitmap.getWidth（）' 参考在android.graphics.Bitmap.createScaledBitmap（Bitmap.java:610）在 app.innova.cristobal.neton.Principal3Activity.onActivityResult（Principal3Activity.java:271）在android.app.Activity.dispatchActivityResult（Activity.java:6428）在android.app.ActivityThread.deliverResults（ActivityThread.java:3695）在 android.app.ActivityThread.handleSendResult（ActivityThread.java:3742）在android.app.ActivityThread.-wrap16（ActivityThread.java）在 android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1393）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:148）在android.app.ActivityThread.main（ActivityThread.java:5417）在java.lang.reflect.Method.invoke（本机方法）

这是我的主要代码：

        myimageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent, "Select image"), 1);

            }
        });



@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        if (requestCode == 1 && resultCode == RESULT_OK) {

            Uri selectedImageUri = data.getData();
            imagepath = getPath(selectedImageUri);
            Bitmap bitmap=BitmapFactory.decodeFile(imagepath);

            ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream();

            //Resized image
            Bitmap resizedBitmap = Bitmap.createScaledBitmap(bitmap, 150, 150, true);
            resizedBitmap.compress(Bitmap.CompressFormat.JPEG,50,bytearrayoutputstream);

            //Round image
            int min = Math.min(resizedBitmap.getWidth(), resizedBitmap.getHeight());

            Bitmap bitmapRounded = Bitmap.createBitmap(min, min, resizedBitmap.getConfig());

            Canvas canvas = new Canvas(bitmapRounded);
            Paint paint = new Paint();
            paint.setAntiAlias(true);
            paint.setShader(new BitmapShader(resizedBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
            canvas.drawRoundRect((new RectF(0.0f, 0.0f, min, min)), min / 2, min / 2, paint);


            myimageView.setImageBitmap(bitmapRounded);

}
}

在清单文件中，我分配了以下权限：

<uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

但是它总是返回一个空位图。

关于我的代码有什么问题的一些建议？

谢谢！

Answer 1

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == 1 && resultCode == RESULT_OK) {


            final Uri imageUri = data.getData();
            final InputStream imageStream = getContentResolver().openInputStream(imageUri);
            final Bitmap selectedImage = BitmapFactory.decodeStream(imageStream);

        ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream();

        //Resized image
        Bitmap resizedBitmap = Bitmap.createScaledBitmap(bitmap, 150, 150, true);
        resizedBitmap.compress(Bitmap.CompressFormat.JPEG,50,bytearrayoutputstream);

        //Round image
        int min = Math.min(resizedBitmap.getWidth(), resizedBitmap.getHeight());

        Bitmap bitmapRounded = Bitmap.createBitmap(min, min, resizedBitmap.getConfig());

        Canvas canvas = new Canvas(bitmapRounded);
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setShader(new BitmapShader(resizedBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
        canvas.drawRoundRect((new RectF(0.0f, 0.0f, min, min)), min / 2, min / 2, paint);


        myimageView.setImageBitmap(bitmapRounded);

}

您需要一个内容解析器来打开输入流到所选图像URI。 Uri.getpath（）返回抽象路径。

Answer 2

添加权限“ checkPermissionREAD_EXTERNAL_STORAGE”

first_object.attr1 = other_columns.attr1
...

} }

Android，将图库中的图像导入imageView

2 个答案: