Android项目实战（五）：TextView自适应大小

对于设置TextView的字体默认大小对于UI界面的好看程度是很重要的，小屏幕设置的文字过大或者大屏幕设置的文字过小都造成UI的不美观

现在就让我们学习自适应大小的TextView控件，即当文字长度变化时，文字的大小会相应的变化，保证显示在一行当中

实现依靠于第三方类库

第三方类来源：

https://github.com/grantland/android-autofittextview

和正常的使用TextView一样，只需要将要自适应的TextView标签设置为<me.grantland.widget.AutofitTextView/>

注意：一定要设置为单行，否定无法显示效果

android:singleLine="true"

<me.grantland.widget.AutofitTextView
            android:id="@+id/output_autofit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/example"
            android:textSize="50sp"
            android:gravity="center"
            android:singleLine="true"
            autofit:minTextSize="8sp"
            />

布局文件：

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:autofit="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        >
        <EditText
            android:id="@+id/input"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:singleLine="true"
            android:hint="@string/input_hint"
            android:text="@string/example"/>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/label_normal"
            />
        <TextView
            android:id="@+id/output"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/example"
            android:textSize="50sp"
            android:gravity="center"
            />
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/label_autofit"
            />
        <me.grantland.widget.AutofitTextView
            android:id="@+id/output_autofit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/example"
            android:textSize="50sp"
            android:gravity="center"
            android:singleLine="true"
            autofit:minTextSize="8sp"
            />
    </LinearLayout>
</ScrollView>

string.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Texttest</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>

    <string name="input_hint">text</string>
    <string name="label_normal">Normal:</string>
    <string name="label_autofit">Autofit:</string>

    <string name="example">This is an example</string>

</resources>

activity

package com.example.texttest;

import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.Menu;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

    private TextView mOutput;
    private TextView mAutofitOutput;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mOutput = (TextView)findViewById(R.id.output);
        mAutofitOutput = (TextView)findViewById(R.id.output_autofit);

        ((EditText)findViewById(R.id.input)).addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
                // do nothing
            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
                mOutput.setText(charSequence);
                mAutofitOutput.setText(charSequence);
            }

            @Override
            public void afterTextChanged(Editable editable) {
                // do nothing
            }
        });
    }
    


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
}

效果：