Question

我有一个活动，其布局只有一个图像视图，我想在用户点击图像时创建它，一个对话框显示按钮以保存图像，但对话框没有出现，是什么错？

    public class ShowImage extends Activity {

    ImageView iv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_show_image);
        iv = (ImageView) findViewById(R.id.ivShowImage);
        String imgUrlPortrait = "some URL";
        ImageLoader.getInstance().displayImage(imgUrlPortrait, iv);
    }

    public void saveImg(View v) {
        final AlertDialog.Builder db = new AlertDialog.Builder(this);
        db.setNeutralButton("Save Image", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                BitmapDrawable drawable = (BitmapDrawable) iv.getDrawable();
                Bitmap bitmap = drawable.getBitmap();
                File sdCardDirectory = Environment.getExternalStorageDirectory();
                File image = new File(sdCardDirectory, "img" + System.currentTimeMillis() + ".png");
                boolean success = false;
                try {
                    FileOutputStream outStream = new FileOutputStream(image);
                    bitmap.compress(Bitmap.CompressFormat.PNG, 100, outStream);
                    outStream.flush();
                    outStream.close();
                    success = true;
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                if (success) {
                    Toast.makeText(getApplicationContext(), "Image saved to SD Card", Toast.LENGTH_LONG).show();
                } else {
                    Toast.makeText(getApplicationContext(), "Error during image saving", Toast.LENGTH_LONG).show();
                }
                AlertDialog dlg = db.create();
                dlg.requestWindowFeature(Window.FEATURE_NO_TITLE);
                dlg.show();
            }
        });
    }

}

这是布局

<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/ivShowImage"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:contentDescription="@string/app_name"
    android:onClick="saveImg"
    tools:context=".ShowImage" >

</ImageView>

这是清单中的活动

<activity
            android:name="com.package.ShowImage"
            android:configChanges="orientation|keyboardHidden|screenSize"
            android:screenOrientation="sensorLandscape"
            android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >
        </activity>

Answer 1

您似乎忘了在ImageView上设置监听器。尝试在onCreate的末尾添加：

iv.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        saveImg(iv);    
    }
});

Answer 2

尝试使用android:clickable="true"这样的ImageView

 <ImageView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/ivShowImage"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:contentDescription="@string/app_name"
    android:onClick="saveImg"
    android:clickable="true"
    tools:context=".ShowImage" >

</ImageView>

Answer 3

结果显示警告对话框未正确放置的代码，现在它的工作原理如下

public class ShowImage extends Activity {

    ImageView iv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_show_image);
        iv = (ImageView) findViewById(R.id.ivShowImage);
        String imgUrlPortrait = "some URL";
        ImageLoader.getInstance().displayImage(imgUrlPortrait, iv);
    }

    public void saveImg(View v) {
        final AlertDialog.Builder db = new AlertDialog.Builder(this);
        db.setNeutralButton("Save Image", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                BitmapDrawable drawable = (BitmapDrawable) iv.getDrawable();
                Bitmap bitmap = drawable.getBitmap();
                File sdCardDirectory = Environment.getExternalStorageDirectory();
                File image = new File(sdCardDirectory, "img" + System.currentTimeMillis() + ".png");
                boolean success = false;
                try {
                    FileOutputStream outStream = new FileOutputStream(image);
                    bitmap.compress(Bitmap.CompressFormat.PNG, 100, outStream);
                    outStream.flush();
                    outStream.close();
                    success = true;
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                if (success) {
                    Toast.makeText(getApplicationContext(), "Image saved to SD Card", Toast.LENGTH_LONG).show();
                } else {
                    Toast.makeText(getApplicationContext(), "Error during image saving", Toast.LENGTH_LONG).show();
                }

            }
        });
                AlertDialog dlg = db.create();
                dlg.requestWindowFeature(Window.FEATURE_NO_TITLE);
                dlg.show();
    }

}

使用“图像视图”将图像从全屏活动保存到SD卡

3 个答案: