前段时间公司要求做个SDK的登录界面，没办法用XML布局了，很头疼。等到要纯代码编界面的时候才发现XML是有多么的好用方便。
没办法啊还是要硬着头皮去把已经编好的布局转换成代码的形式。
弄好后才发觉，其实也不难。
先了解一下什么是LinearLayout
我觉得LinearLayout也就是一个视图的根布局主要的也就是layout_width和layout_height，线性布局控件，它包含的子控件将以横向或竖向的方式排列，按照相对位置来排列所有的widgets或者其他的containers,超过边界时，某些控件将缺失或消失。
所以简单实用不用太担心，只要设置宽高边距就好，布局就是来约束控件的，把控件放在布局上面就行。
<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:gravity=”center_horizontal”
android:orientation=”vertical”
android:paddingBottom=”@dimen/fab_labels_margin”
tools:context=”com.example.youhao.xxlogin.tjLoginActivity”>
其中要注意的是
android:layout_width
android:layout_height
android:gravity
….这些属性都可以在LinearLayout中找到
LinearLayout layoutRoot =newLinearLayout(this);
layoutRoot.setLayoutParams(layoutParamsRoot);
layoutRoot.setOrientation(LinearLayout.VERTICAL);
现在已经把我们主体的界面约束已经放上，现在要放东西进去了
界面上是
<ProgressBar
android:id=”@+id/login_progress”
style=”?android:attr/progressBarStyleLarge”
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:layout_marginBottom=”8dp”
android:visibility=”gone” />
把里面的约束提取出来
LinearLayout.LayoutParams layoutParamsRoot =newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParamsRoot.gravity= Gravity.CENTER;
控件创建出来
mProgressView=newProgressBar(this);
mProgressView.setLayoutParams(newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
mProgressView.setBackgroundColor(Color.WHITE);
mProgressView.setBottom(8);
mProgressView.setVisibility(View.GONE);
mLoginFormView=newScrollView(this);
mLoginFormView.setLayoutParams(newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT));
放进根视图去
layoutRoot.addView(mProgressView);
这样就一个控件从创建到布局完成了，布局就像穿衣服一样，每个界面都要穿衣服，不然都不能出门。
复杂一点的界面一件套一件，都能完成对应的效果。
特意从废纸篓捞除了原来的XML布局文件来做个一一对应。
<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:gravity=”center_horizontal”
android:orientation=”vertical”
android:paddingBottom=”@dimen/fab_labels_margin”
tools:context=”com.example.youhao.xxlogin.tjLoginActivity”>
<ProgressBar
android:id=”@+id/login_progress”
style=”?android:attr/progressBarStyleLarge”
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:layout_marginBottom=”8dp”
android:visibility=”gone” />
<ScrollView
android:id=”@+id/login_form”
android:layout_width=”match_parent”
android:layout_height=”match_parent”>
<LinearLayout
android:id=”@+id/email_login_form”
android:layout_width=”match_parent”
android:layout_height=”wrap_content”
android:orientation=”vertical”>
<android.support.v7.widget.AppCompatTextView
android:layout_width=”match_parent”
android:layout_height=”wrap_content”
android:text=”登录”
android:textAlignment=”center”
android:textSize=”30dp”/>
<android.support.design.widget.TextInputLayout
android:layout_width=”match_parent”
android:layout_height=”wrap_content”>
<AutoCompleteTextView
android:id=”@+id/email”
android:layout_width=”match_parent”
android:layout_height=”wrap_content”
android:hint=”@string/prompt_email”
android:inputType=”textEmailAddress”
android:maxLines=”1″/>
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:layout_width=”match_parent”
android:layout_height=”wrap_content”>
<EditText
android:id=”@+id/password”
android:layout_width=”match_parent”
android:layout_height=”wrap_content”
android:hint=”@string/prompt_password”
android:imeActionId=”@+id/login”
android:imeActionLabel=”@string/action_sign_in_short”
android:imeOptions=”actionUnspecified”
android:inputType=”textPassword”
android:maxLines=”1″/>
</android.support.design.widget.TextInputLayout>
<Button
android:id=”@+id/email_sign_in_button”
style=”?android:textAppearanceSmall”
android:layout_width=”match_parent”
android:layout_height=”wrap_content”
android:layout_marginTop=”16dp”
android:text=”登录”
android:textStyle=”bold” />
<Button
android:id=”@+id/email_regist_in_button”
style=”?android:textAppearanceSmall”
android:layout_width=”match_parent”
android:layout_height=”wrap_content”
android:layout_marginTop=”16dp”
android:text=”注册”
android:textStyle=”bold” />
</LinearLayout>
</ScrollView>
</LinearLayout>
对应的布局代码如下
mProgressView=newProgressBar(this);
mProgressView.setLayoutParams(newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
mProgressView.setBackgroundColor(Color.WHITE);
mProgressView.setBottom(8);
mProgressView.setVisibility(View.GONE);
mLoginFormView=newScrollView(this);
mLoginFormView.setLayoutParams(newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT));
//根布局参数
LinearLayout.LayoutParams layoutParamsRoot =newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParamsRoot.gravity= Gravity.CENTER;
//根布局
LinearLayout layoutRoot =newLinearLayout(this);
layoutRoot.setLayoutParams(layoutParamsRoot);
layoutRoot.setOrientation(LinearLayout.VERTICAL);
layoutRoot.addView(mProgressView);
//title布局
LinearLayout.LayoutParams layoutParamsTitle =newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParamsTitle.gravity=Gravity.CENTER_HORIZONTAL;
//title
AppCompatTextView title =newAppCompatTextView(this);
title.setText(“登录”);
title.setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
title.setTextSize(30);
layoutRoot.addView(title,layoutParamsTitle);
//用户名text布局
LinearLayout.LayoutParams layoutParamsEmil =newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParamsEmil.gravity=Gravity.CENTER_HORIZONTAL;
//用户名text
mEmailView=newAutoCompleteTextView(this);
mEmailView.setHint(“Email”);
mEmailView.setInputType(0);
mEmailView.setMaxLines(1);
//用户名布局
TextInputLayout inputLayoutEmil =newTextInputLayout(this);
inputLayoutEmil.addView(mEmailView,layoutParamsEmil);
layoutRoot.addView(inputLayoutEmil,newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
//密码Text布局
LinearLayout.LayoutParams layourParamsPassword =newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layourParamsPassword.gravity=Gravity.CENTER_HORIZONTAL;
//密码Text
mPasswordView=newEditText(this);
mPasswordView.setHint(“Password”);
mPasswordView.setImeActionLabel(“Sign in”,0);
mPasswordView.setImeOptions(0);
mPasswordView.setInputType(InputType.TYPE_CLASS_TEXT| InputType.TYPE_TEXT_VARIATION_PASSWORD);
mPasswordView.setMaxLines(1);
//密码布局
TextInputLayout inputLayoutPassword =newTextInputLayout(this);
inputLayoutPassword.addView(mPasswordView,layourParamsPassword);
layoutRoot.addView(inputLayoutPassword,newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
//登录Button布局
LinearLayout.LayoutParams layoutParamsLoginButton =newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParamsLoginButton.topMargin=16;
layoutParamsLoginButton.gravity=Gravity.CENTER_HORIZONTAL;
//登录Button
Button buttonLogin =newButton(this);
buttonLogin.setText(“登录”);
buttonLogin.setOnClickListener(newOnClickListener() {
@Override
public voidonClick(View view) {
attemptLogin();
}
});
layoutRoot.addView(buttonLogin,layoutParamsLoginButton);
//注册Button布局
LinearLayout.LayoutParams layoutParamsRegistButton =newLinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParamsLoginButton.topMargin=16;
layoutParamsRegistButton.gravity=Gravity.CENTER_HORIZONTAL;
//注册Button
Button buttonRegist =newButton(this);
buttonRegist.setText(“注册”);
buttonRegist.setOnClickListener(newOnClickListener() {
@Override
public voidonClick(View view) {
jumpRegist();
}
});
layoutRoot.addView(buttonRegist,layoutParamsRegistButton);
mLoginFormView.addView(layoutRoot);
setContentView(mLoginFormView);
