我正在尝试使用horizontalscrollview做一个简单的图像库示例并动态添加图像。我搜索了一些例子,但大多数都太复杂了。有一个简单的例子说明如何做到这一点?
答案 0 :(得分:12)
Here是一个简单的例子,它实现了水平滚动视图,看起来像图像库
这会对你有所帮助
在布局中添加HorizontalScrollView:
<LinearLayout 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"
android:orientation="vertical">
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="@+id/mygallery"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
/>
</HorizontalScrollView>
</LinearLayout>
主要Java代码:
package com.example.androidhorizontalscrollviewgallery;
import java.io.File;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Toast;
public class MainActivity extends Activity {
LinearLayout myGallery;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myGallery = (LinearLayout)findViewById(R.id.mygallery);
String ExternalStorageDirectoryPath = Environment
.getExternalStorageDirectory()
.getAbsolutePath();
String targetPath = ExternalStorageDirectoryPath + "/test/";
Toast.makeText(getApplicationContext(), targetPath, Toast.LENGTH_LONG).show();
File targetDirector = new File(targetPath);
File[] files = targetDirector.listFiles();
for (File file : files){
myGallery.addView(insertPhoto(file.getAbsolutePath()));
}
}
View insertPhoto(String path){
Bitmap bm = decodeSampledBitmapFromUri(path, 220, 220);
LinearLayout layout = new LinearLayout(getApplicationContext());
layout.setLayoutParams(new LayoutParams(250, 250));
layout.setGravity(Gravity.CENTER);
ImageView imageView = new ImageView(getApplicationContext());
imageView.setLayoutParams(new LayoutParams(220, 220));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setImageBitmap(bm);
layout.addView(imageView);
return layout;
}
public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth, int reqHeight) {
Bitmap bm = null;
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
bm = BitmapFactory.decodeFile(path, options);
return bm;
}
public int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
if (width > height) {
inSampleSize = Math.round((float)height / (float)reqHeight);
} else {
inSampleSize = Math.round((float)width / (float)reqWidth);
}
}
return inSampleSize;
}
}
注意:在此示例中,即使不在屏幕中,也不会删除HorizontalScrollView中的位图。所以如果加载的位图太多,将抛出java.lang.OutOfMemoryError的错误!
答案 1 :(得分:-7)
您可以创建一个div并将溢出设置为隐藏然后将另一个嵌套在其中,其中所有图像的高度或宽度取决于您想要水平的动画,因此请按宽度乘以图像数量并记住包括此中的边距。然后你编写一个jQuery动画来运行在更大的div上,这将根据你的偏好再次向左或向右移动
eg $('pic').animate({left:'_____ <- enter width of single image together with margin here ' +'px','slow' <-- whatever speed you prefer);
然后从那里玩它。您的处理程序可以再次单击另一个按钮或图像...首选项。它没有太多编码就非常灵活,它不是最好的选择。如果这不适合您,则创建一个图像数组并循环遍历它们,而不是使用这些特定尺寸进行滚动。祝你好运。希望我帮助过你。