将边距设置为线性布局崩溃

Question

当我尝试通过代码设置边距时，我的应用程序崩溃了。

 <LinearLayout
            android:id="@+id/lay_AC"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="25dp"
            android:gravity="center"
            android:orientation="vertical" >

            <Button
                android:id="@+id/btn_f_ac"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/accesories_icon"
                android:minWidth="48dp"
                android:textColor="#151551" />

            <TextView
                android:id="@+id/TextView06"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Accesories"
                android:textColor="#f82229"
                android:textSize="12sp" />
        </LinearLayout>

代码：

LinearLayout lay_AC;
lay_AC = (LinearLayout) findViewById(R.id.lay_f_vd);

LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
lp.leftMargin = 300;
lay_AC.setLayoutParams(lp);

进口：

import java.io.File;
import java.util.ArrayList;

import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.graphics.Typeface;
import android.graphics.drawable.AnimationDrawable;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout.LayoutParams;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.view.animation.Animation.AnimationListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;

错误：

07-03 14:48:22.592: W/dalvikvm(27674): threadid=1: thread exiting with uncaught exception (group=0x40a431f8)
07-03 14:48:22.602: E/AndroidRuntime(27674): FATAL EXCEPTION: main
07-03 14:48:22.602: E/AndroidRuntime(27674): java.lang.ClassCastException: android.widget.LinearLayout$LayoutParams cannot be cast to android.widget.RelativeLayout$LayoutParams
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.RelativeLayout$DependencyGraph.findRoots(RelativeLayout.java:1317)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.RelativeLayout$DependencyGraph.getSortedViews(RelativeLayout.java:1264)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.RelativeLayout.sortChildren(RelativeLayout.java:292)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:314)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.View.measure(View.java:12728)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:293)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.View.measure(View.java:12728)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1369)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:660)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:553)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.View.measure(View.java:12728)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:293)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2092)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.View.measure(View.java:12728)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1064)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2442)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.os.Handler.dispatchMessage(Handler.java:99)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.os.Looper.loop(Looper.java:137)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at android.app.ActivityThread.main(ActivityThread.java:4424)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at java.lang.reflect.Method.invokeNative(Native Method)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at java.lang.reflect.Method.invoke(Method.java:511)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
07-03 14:48:22.602: E/AndroidRuntime(27674):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

首先，您为LinearLayout 传递了错误的ID。

将lay_AC = (LinearLayout) findViewById(R.id.lay_f_vd);行替换为

lay_AC = (LinearLayout) findViewById(R.id.lay_AC);

您的导入也有问题。 尝试导入

import android.widget.LinearLayout.LayoutParams;

而不是

import android.widget.RelativeLayout.LayoutParams;

Answer 2

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
     LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);

layoutParams.setMargins(30, 20, 30, 0);

使用上述代码设置边距

Answer 3

你不能直接使用这个；

lp.leftMargin = 300;
lay_AC.setLayoutParams(lp);

你需要像这样在你的 LinaerLayout 上提供一些包装器：

<LinearLayout >

  <!-- Put your linear layout which you want to set margin or padding-->


<LinearLayout>

Answer 4

从

更改您的导入语句

 import android.widget.RelativeLayout.LayoutParams;

到

import android.view.ViewGroup.LayoutParams;

并更改线性布局 id

R.id.lay_f_vd

到

R.id.lay_AC