Android WebView 上传图片注意事项和完整代码参考

重点说明

机型4.4.0 可能不支持

Webview上传文件的那些坑

混淆说明：正式版不混淆openFileChooser()就好了。

参考资料

-keepclassmembers class * extends android.webkit.WebChromeClient{
public void openFileChooser(...);
}

在Web页面上点击选择文件的控件()时，会回调WebChromeClient下的openFileChooser()（5.0及以上系统回调onShowFileChooser()）。这个时候我们在openFileChooser方法中通过Intent打开系统相册或者支持该Intent的第三方应用来选择图片

最求完美的Google攻城狮们对openFileChooser做了多次修改，在5.0上更是将回调方法该为了onShowFileChooser。所以为了解决这一问题，兼容各个版本，我们需要对openFileChooser()进行重载，同时针对5.0及以上系统提供onShowFileChooser()方法：

完整代码

import android.annotation.TargetApi;
import android.app.Activity;
import android.content.ClipData;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;

public class MainActivity extends AppCompatActivity {

private ValueCallback<Uri> uploadMessage;
private ValueCallback<Uri[]> uploadMessageAboveL;
private final static int FILE_CHOOSER_RESULT_CODE = 10000;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

WebView webview = (WebView) findViewById(R.id.web_view);
assert webview != null;
WebSettings settings = webview.getSettings();
settings.setUseWideViewPort(true);
settings.setLoadWithOverviewMode(true);
settings.setJavaScriptEnabled(true);
webview.setWebChromeClient(new WebChromeClient() {

// For Android < 3.0
public void openFileChooser(ValueCallback<Uri> valueCallback) {
uploadMessage = valueCallback;
openImageChooserActivity();
}

// For Android  >= 3.0
public void openFileChooser(ValueCallback valueCallback, String acceptType) {
uploadMessage = valueCallback;
openImageChooserActivity();
}

//For Android  >= 4.1
public void openFileChooser(ValueCallback<Uri> valueCallback, String acceptType, String capture) {
uploadMessage = valueCallback;
openImageChooserActivity();
}

// For Android >= 5.0
@Override
public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
uploadMessageAboveL = filePathCallback;
openImageChooserActivity();
return true;
}
});
//改成自己的url
String targetUrl = "file:///android_asset/up.html";
webview.loadUrl(targetUrl);
}

private void openImageChooserActivity() {
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("image/*");
startActivityForResult(Intent.createChooser(i, "Image Chooser"), FILE_CHOOSER_RESULT_CODE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == FILE_CHOOSER_RESULT_CODE) {
if (null == uploadMessage && null == uploadMessageAboveL) return;
Uri result = data == null || resultCode != RESULT_OK ? null : data.getData();
if (uploadMessageAboveL != null) {
onActivityResultAboveL(requestCode, resultCode, data);
} else if (uploadMessage != null) {
uploadMessage.onReceiveValue(result);
uploadMessage = null;
}
}
}

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private void onActivityResultAboveL(int requestCode, int resultCode, Intent intent) {
if (requestCode != FILE_CHOOSER_RESULT_CODE || uploadMessageAboveL == null)
return;
Uri[] results = null;
if (resultCode == Activity.RESULT_OK) {
if (intent != null) {
String dataString = intent.getDataString();
ClipData clipData = intent.getClipData();
if (clipData != null) {
results = new Uri[clipData.getItemCount()];
for (int i = 0; i < clipData.getItemCount(); i++) {
ClipData.Item item = clipData.getItemAt(i);
results[i] = item.getUri();
}
}
if (dataString != null)
results = new Uri[]{Uri.parse(dataString)};
}
}
uploadMessageAboveL.onReceiveValue(results);
uploadMessageAboveL = null;
}
}