如何通过在android中触摸来拖动图像？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/3669239/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
提示：将鼠标放在中文语句上可以显示对应的英文。显示中英文
时间：2020-08-20 11:16:49 来源:igfitidea点击:
how to drag an image by touching in android?
提问by James
how to drag an image by touching in android? Please Help me with a sample code.
如何通过在android中触摸来拖动图像？请帮助我提供示例代码。
回答by Prateek Raj
package com.examples.Touchmoveimage;
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout.LayoutParams;
public class Touchmoveimage extends Activity {
int windowwidth;
int windowheight;
private LayoutParams layoutParams;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
windowwidth = getWindowManager().getDefaultDisplay().getWidth();
windowheight = getWindowManager().getDefaultDisplay().getHeight();
final ImageView balls = (ImageView) findViewById(R.id.ball);
balls.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
LayoutParams layoutParams = (LayoutParams) balls.getLayoutParams();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
break;
case MotionEvent.ACTION_MOVE:
int x_cord = (int) event.getRawX();
int y_cord = (int) event.getRawY();
if (x_cord > windowwidth) {
x_cord = windowwidth;
}
if (y_cord > windowheight) {
y_cord = windowheight;
}
layoutParams.leftMargin = x_cord - 25;
layoutParams.topMargin = y_cord - 75;
balls.setLayoutParams(layoutParams);
break;
default:
break;
}
return true;
}
});
}
}
works good!!
效果很好！！
回答by M.ES
回答by Vinay
There is no direct way to do drag and drop in Android. You have to write some classes. Look into DragController.java, DragLayer.java in Launcher project.
在 Android 中没有直接的方法可以进行拖放操作。你必须写一些类。查看 Launcher 项目中的 DragController.java、DragLayer.java。
